TO:
All DNP3 User Group Members
RE:
DNP3 Documentation Library
DATE: March 15, 2002
Thank you for your membership in the DNP3 Users Group and for your support of the DNP3
protocol!
This file includes all DNP3-related documents available as of March 13, 2002 and will be
updated on an as-needed basis.
The purpose of this file is to provide a single source document in a universal format for the
convenience of all DNP3 User Group Members. Therefore, this file has been created in Adobe
Portable Document Format (.pdf).
If you do not have access to Adobe Acrobat, you may download a free Acrobat Reader directly
from the Adobe website (www.Adobe.com).
The bookmarks in this document will enable quick navigation through all of the existing DNP3
documentation. Simple character string searches are also allowed (i.e., Object 10) using the
standard Windows key sequence (Ctrl-F).
Please let us know if you have any comments or questions regarding this document.
Sincerely,
The DNP3 Executive Committee
A DNP3 Protocol Primer
This is a primer for people who want a quick understanding of DNP3 without having to comb through the tedious
details of a complex specification.
So let us start with what it is. Protocols define the rules by which devices talk with each other, and DNP3 is a
protocol for transmission of data from point A to point B using serial communications. It has been used primarily by
utilities like the electric companies, but it operates suitably in other areas.
A typical electric company may have a centralized operations center that monitors the state of all the equipment in
each of its substations. In the operations center, a powerful computer stores all of the incoming data and displays
the system for the human operators. Substations have many devices that need monitoring (are circuit breakers
opened or closed?), current sensors (how much current is flowing?) and voltage transducers (what is the line
potential?). That only scratches the surface; a utility is interested in monitoring many parameters, too numerous to
discuss here. The operations personnel often need to switch sections of the power grid into or out of service. One
or more computers are situated in the substation to collect the data for transmission to the master station in the
operations center. The substation computers are also called upon to energize or de-energize the breakers and
voltage regulators.
DNP3 provides the rules for substation computers and master station computers to communicate data and control
commands. DNP3 is a non-proprietary protocol that is available to anyone. Only a nominal fee is charged for
documentation, but otherwise it is available worldwide with no restrictions. This means a utility can purchase master
station and substation computing equipment from any manufacturer and be assured that they will reliably talk to each
other. Vendors compete based upon their computer equipment’s features, costs and quality factors instead of who
has the best protocol. Utilities are not stuck with one manufacturer after the initial sale.
What do the computers talk about? The substation computer gathers data for transmission to the master as
1.
2.
3.
4.
Binary input data that is useful to monitor two-state devices. For example a circuit breaker is closed or
tripped or a pipeline pressure alarm shows normal or excessive.
Analog input data that conveys voltages, currents, power, reservoir water levels and temperatures.
Count input data that reports kilowatt hours of energy.
Files that contain configuration data.
The master station issues control commands that take the form of
1.
2.
Close or trip a circuit breaker, raise or lower a gate, and open or close a valve.
Analog output values to set a regulated pressure or set a desired voltage level.
Other things the computers talk to each other about are synchronizing the time and date, sending historical or logged
data, waveform data, and on and on.
DNP3 was designed to optimize the transmission of data acquisition information and control commands from one
computer to another. It is not a general purpose protocol for transmitting hypertext, multimedia or huge files.
The terms server and client are applicable to DNP3 systems. For our purposes, the definition of a server is a device
or software process that has data or information that someone else wants. Substation computers are servers. A
client is a device or software process that requests data from a server. A master station is a client.
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Master (Client)
Binary
Input
8
7
6
5
4
3
2
1
0
Control
Output
Analog
Input Counter
Input
4
3
3
2
2
1
1
0
0
6
5
4
3
2
1
0
Slave (Server)
Binary
Input
8
7
6
5
4
3
2
1
0
Analog
Output
4
3
2
1
0
Control
Output
Analog
Input Counter
Input
4
3
3
2
2
1
1
0
0
6
5
4
3
2
1
0
DNP3 User's Code
DNP3 User's Code
DNP3
Software
DNP3
Software
Analog
Output
4
3
2
1
0
Physical Media
User Requests
User Responses
Figure 1
Figure 1 shows the client-server relationship and gives a simplistic view of the databases and software processes
involved. The master or client is on the left side of figure 1, and the slave or server is on the right side.
A series of square blocks at the top of the server depicts its databases and output devices. The various data types
are conceptually organized as arrays. An array of binary input values represents states of physical or logical boolean
devices. Values in the analog input array represent input quantities that the server measured or computed. An array
of counters represents count values, such as kilowatt hours, that are ever increasing (until they reach a maximum
and then roll over to zero and start counting again.) Control outputs are organized into an array representing
physical or logical on-off, raise-lower and trip-close points. Lastly, the array of analog outputs represents physical or
logical analog quantities such as those used for setpoints.
The elements of the arrays are labeled 0 through N - 1 where N is the number of blocks shown for the respective
data type. In DNP3 terminology, the element numbers are called the point indexes. Indexes are zero-based in
DNP3, that is, the lowest element is always identified as zero. Some protocols use 1-based indexing.
Notice that the DNP3 client, or master, also has a similar database for the input data types (binary, analog and
counter.) The master, or client, uses values in its database for the specific purposes of displaying system states,
closed-loop control, alarm notification, billing, and much, much more. An objective of the client is to keep its
database updated. It accomplishes this by sending requests to the server (slave) asking it to return the values in the
server’s database. This is termed polling. The server responds to the client’s request by transmitting the contents of
its database. Arrows are drawn at the bottom of figure 1 showing the direction of the requests (toward the server)
and the direction of the responses (toward the client.) Later we will discuss systems whereby the slaves transmit
responses without being asked.
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The client and the server shown in figure 1 each have two software layers. The top layer is the DNP3 user layer. In
the client, it is the software that interacts between the database and initiates the requests for the server’s data. In
the server, it is the software that fetches the requested data from the server’s database for responding to client
requests. It is interesting to note, that if no physical separation of the client and server existed, eliminating the DNP3
might be possible by connecting these two upper layers together. However, since physical, or possibly logical
separation of the client and server exists, DNP3 software is placed at a lower level. The DNP3 user’s code uses the
DNP3 software for transmission of requests or responses to the matching DNP3 user’s code at the other end.
More will be said about data types and software layers later, but first we want to examine a few typical system
architectures where DNP3 is used.
DNP3
Client
(Master)
DNP3
Server
(Slave)
One-on-One
DNP3
Client
(Master)
DNP3
Server
(Slave)
DNP3
Server
(Slave)
DNP3
Server
(Slave)
Multidrop
DNP3
Client
(Master)
DNP3
Server
Client
(Slave)
(Master)
DNP3
Server
(Slave)
Hierarchical
DNP3
Client
(Master)
DNP3
Server
(Slave)
XYZ
Client
(Master)
XYZ
Server
(Slave)
XYZ
Server
(Slave)
DNP3
Server
(Slave)
DNP3
Server
(Slave)
Data Concentrator
XYZ
Client
(Master)
XYZ
Server
(Slave)
DNP3
Client
(Master)
Data Concentrator
Figure 2
Figure 2 shows common system architectures in use today. At the top is a simple one-on-one system having one
master station and one slave. The physical connection between the two is typically a dedicated or dial-up telephone
line.
The second type of system is known as a multidrop design. One master station communicates with multiple slave
devices. Conversations are typically between the client and one server at a time. The master requests data from
the first slave, then moves onto the next slave for its data, and continually interrogates each slave in a round robin
order. The communication media is a multi-dropped telephone line, fiber optic cable, or radio. Each slave can hear
messages from the master and is only permitted to respond to messages addressed to itself. Slaves may or may
not be able to hear each other.
In some multidrop forms, communications are peer-to-peer. A station may operate as a client for gathering
information or sending commands to the server in another station. And then, it may change roles to become a
server to another station.
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The middle row in figure 2 shows a hierarchical type system where the device in the middle is a server to the client at
the left and is a client with respect to the server on the right. The middle device is often termed a sub-master.
Both lines at the bottom of figure 2 show data concentrator applications and protocol converters. A device may
gather data from multiple servers on the right side of the figure and store this data in its database where it is
retrievable by a master station client on the left side of the figure. This design is often seen in substations where the
data concentrator collects information from local intelligent devices for transmission to the master station.
In recent years, several vendors have used TCP/IP to transport DNP3 messages in lieu of the media discussed
above. Link layer frames, which we have not talked about yet, are embedded into TCP/IP packets. This approach
has enabled DNP3 to take advantage of Internet technology and permitted economical data collection and control
between widely separated devices.
Many communication circuits between the devices are imperfect. They are susceptible to noise and signal distortion.
The DNP3 software is layered to provide reliable data transmission and to effect an organized approach to the
transmission of data and commands. Figure 3 shows the layering that was not shown in figure 1.
Master (Client)
Binary
Input
8
7
6
5
4
3
2
1
0
8
7
6
5
4
3
2
1
0
Analog
Counter
4
3
2
1
0
Slave (Server)
Binary
Input
3
2
1
0
Control
Output
Analog
Counter
4
3
2
1
0
3
2
1
0
6
5
4
3
2
1
0
DNP3 User's Code
DNP3 User's Code
DNP3
Application Layer
DNP3
Application Layer
Pseudo Transport Layer
Pseudo Transport Layer
DNP3
Link Layer
DNP3
Link Layer
Analog
Output
4
3
2
1
0
Physical Media
User Requests
User Responses
Figure 3
The link layer has the responsibility of making the physical link reliable. It does this by providing error detection and
duplicate frame detection. The link layer sends and receives packets, which in DNP3 terminology, are called frames.
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Sometimes transmission of more than one frame is necessary to transport all of the information from one device to
another.
A DNP3 frame consists of a header and data section. The header specifies the frame size, which DNP3 station
should receive the frame, which DNP3 device sent the frame and data link control information. The data section is
commonly called the payload and contains the data passed down from the layers above.
DNP3 Frame
Header
Data
Header
Sync
Length
Link Control
Destination
Address
Source Address
CRC
Every frame begins with two sync bytes that help the receivers determine where the frame begins. The length
specifies the number of octets in the remainder of the frame, not including CRC check octets. The link control octet
is used between sending and receiving link layers to coordinate their activities.
A destination address specifies which DNP3 device should process the data, and the source address identifies
which DNP3 device sent the message. Having both destination and source addresses satisfies at least one
requirement for peer-to-peer communications because the receiver knows where to direct its responses. 65520
individual addresses are available. Every DNP3 device must have a unique address within the collection of devices
sending and receiving messages to and from each other. Three destination addresses are reserved by DNP3 to
denote an all-call message; that is, the frame should be processed by all DNP3 devices. Thirteen addresses are
reserved for special needs in the future.
The data payload in the link frame contains a pair of CRC octets for every 16 data octets. This provides a high
degree of assurance that communication errors can be detected. The maximum number of octets in the data
payload is 250, not including CRC octets. (The longest link layer frame is 292 octets if all the CRC and header
octets are counted.)
One often hears the term “link layer confirmation” when DNP3 is discussed. A feature of DNP3's link layer is the
ability for the transmitter of the frame to request the receiver to confirm that the frame arrived. Using this feature is
optional, and it is often not employed. It provides an extra degree of assurance of reliable communications. If a
confirmation is not received, the link layer may retry the transmission. Some disadvantages are the extra time
required for confirmation messages and waiting for multiple timeouts when retries are configured.
It is the responsibility of the transport layer to break long messages into smaller frames sized for the link layer to
transmit, or when receiving, to reassemble frames into the longer messages. In DNP3 the transport layer is
incorporated into the application layer. The transport layer requires only a single octet within the message to do its
work. Therefore, since the link layer can handle only 250 data octets, and one of those is used for the transport
function, then each link layer frame can hold as many as 249 application layer octets.
Application layer messages are broken into fragments. Fragment size is determined by the size of the receiving
device’s buffer. It normally falls between 2048 and 4096 bytes. A message that is larger than a one fragment
requires multiple fragments. Fragmenting messages is the responsibility of the application layer.
Note that an application layer fragment of size 2048 must be broken into 9 frames by the transport layer, and a
fragment size of 4096 needs 17 frames. Interestingly, it has been learned by experience that communications are
sometimes more successful for systems operating in high noise environments if the fragment size is significantly
reduced.
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The application layer works together with the transport and link layers to enable reliable communications. It provides
standardized functions and data formatting with which the user layer above can interact. Before functions, data
objects and variations can be discussed, the terms static, events and classes need to be covered.
In DNP3, the term static is used with data and refers to the current value. Thus static binary input data refers to the
present on or off state of a bi-state device. Static analog input data contains the value of an analog at the instant it is
transmitted. One possibility DNP3 allows is requesting some or all of the static data in a slave device.
DNP3 events are associated with something significant happening. Examples are state changes, values exceeding
some threshold, snapshots of varying data, transient data and newly available information. An event occurs when a
binary input changes from an on to an off state or when an analog value changes by more than its configured
deadband limit. DNP3 provides the ability to report events with and without time stamps so that the client can
generate a time sequence report.
The user layer can direct DNP3 to request events. Usually, a client is updated more rapidly if it mostly polls for
events from the server and only occasionally asks for static data as an integrity measure. The reason updates are
faster is because the number of events generated between server interrogations is small and, therefore, less data
must be returned to the client.
DNP3 goes a step further by classifying events into three classes. When DNP3 was conceived, class 1 events were
considered as having higher priority than class 2 events, and class 2 were higher than class 3 events. While that
scheme can be still be configured, some DNP3 users have developed other strategies more favorable to their
operation for assigning events into the classes. The user layer can request the application layer to poll for class 1, 2
or 3 events or any combination of them.
DNP3 has provisions for representing data in different formats. Examination of analog data formats is helpful to
understand the flexibility of DNP3. Static, current value, analog data can be represented by variation numbers as
follows:
1.
2.
3.
4.
5.
6.
A 32-bit integer value with flag,
A 16-bit integer value with flag,
A 32-bit integer value,
A 16-bit integer value,
A 32-bit floating point value with flag and
A 64-bit floating point value with flag.
The flag referred to is a single octet with bit fields indicating whether the source is on-line, value contains a
restart value, communications are lost with the source, the data is forced and the value is over range.
Not all DNP3 devices can transmit or interpret all six variations. Later, DNP3 levels are discussed, but for now,
suffice it to say that DNP3 devices must be able to transmit the simplest variations so that any receiver can interpret
the contents.
Event analog data can be represented by these variations:
1.
2.
3.
4.
5.
6.
7.
8.
A 32-bit integer value with flag,
A 16-bit integer value with flag,
A 32-bit integer value with flag and event time,
A 16-bit integer value with flag and event time,
A 32-bit floating point value with flag,
A 64-bit floating point value with flag,
A 32-bit floating point value with flag and event time and
A 32-bit floating point value with flag and event time.
The flag has the same bit fields as for the static variations.
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It looks like a variation one or two analog event cannot be differentiated from a variation one or two static analog
value. DNP3 solves this predicament by assigning object numbers. Static analog values are assigned as object 30,
and event analog values are assigned as object 32. Static analog values, object 30, can be formatted in one of 6
variations, and event analog values, object 32, can be formatted in one of 8 variations.
When a DNP3 server transmits a message containing response data, the message identifies the object number and
variation of every value within the message. Object and variation numbers are also assigned for counters, binary
inputs, controls and analog outputs. In fact, all valid data types and formats in DNP3 are identified by object and
variation numbers. Defining the allowable objects and variations helps DNP3 assure interoperability between
devices. DNP3's basic documentation contains a library of valid objects and their variations.
The client’s user layer formulates its request for data from the server by telling the application layer what function to
perform, like reading, and specifying which objects it wants from the server. The request can specify how many
objects it wants or it can specify specific objects or a range of objects from index number X through index number Y.
The application layer then passes the request down through the transport layer to the link layer that, in turn, sends
the message to the server. The link layer at the server checks the frames for errors and passes them up to the
transport layer where the complete message is assembled in the server’s application layer. The application layer
then tells the user layer which objects and variations were requested.
Responses work similarly, in that, the server’s user layer fetches the desired data and presents it to the application
layer that formats the data into objects and variations. Data is then passed downward, across the communication
channel and upward to the client’s application layer. Here the data objects are presented to the user layer in a form
that is native to the client’s database.
Reading data was mentioned in the above two paragraphs, but DNP3 software is designed to handle other functions.
For one the client can set the time in the server. The client can transmit freeze accumulator requests, and it can
transmit requests for control operations and setting of analog output values using select-before-operate or directoperate sequences.
One area that has not been covered yet is transmission of unsolicited messages. This is a mode of operating where
the server spontaneously transmits a response, possibly containing data, without having received a specific request
for the data. Not all servers have this capability, but those that do must be configured to operate in this mode. This
mode is useful when the system has many slaves and the master requires notification as soon as possible after a
change occurs. Rather than waiting for a master station polling cycle to get around to it, the slave simply transmits
the change.
To configure a system for unsolicited messages, a few basics need to be considered. First, spontaneous
transmissions should generally occur infrequently, otherwise, too much contention can occur, and controlling media
access via master station polling would be better. The second basic issue is that the server should have some way
of knowing whether it can transmit without stepping on someone else’s message in progress. DNP3 leaves
specification of algorithms to the system implementor.
One last area of discussion involves implementation levels. The DNP3 organization recognizes that supporting
every feature of DNP3 is not necessary for every device. Some devices are limited in memory and speed and do not
need specific features, while other devices must have the more advanced features to accomplish their task. DNP3
organizes complexity into three levels. At the lowest level, level 1, only very basic functions must be provided and all
others are optional. Level 2 handles more functions, objects and variations, and level 3 is even more sophisticated.
Within each level only certain combinations of request formats and response formats are required. This was done to
limit software code in clients and servers while still assuring interoperability.
It should be apparent by now that DNP3 is a protocol that fits well into the data acquisition world. It transports data
as generic values, it has a rich set of functions, and it was designed to work in a wide area communications network.
The standardized approach of objects and variations, and link, transport and application layers, plus public
availability makes DNP3 a protocol to be regarded.
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Copyright, DNP Users Group, 2000
Author:
Ken Curtis from Woodland Engineering wrote this paper to help the many people who are just getting into or
considering DNP3 for their operation. Ken is a consulting engineer that has been contracted to write software for
DAQ Electronics who also sponsors his participation in the DNP Technical Committee. Valuable editing assistance
was provided by Mike Thesing of Advanced Control Systems.
DNP Users Group:
Mail Address:
DNP Users Group
PO Box 43075, DVPO
Calgary, AB T2J 7A7
Canada
Fax:
403-271-1319
Email:
dnp@home.com
Website:
www.dnp.org
1 June 2000
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Copyright, DNP Users Group, 2000
DOCUMENT REVISION HISTORY
Name of Document: DNP V3.00 Data Link Layer Protocol Description
Network File Name: P009-0PD.DL
Original Author: Malcolm Smith/Jim McFadyen
Date and Version of Preliminary Release: September 1991 Version 0.00
Associated Software Release(s): DNP V3.00
Revisions Since Preliminary Release
Date
Version
By Whom:
Sept. 30/91 0.00A
N. Male
Pages
Affected:
All
Nov. 11/91
Nov. 18/91
Jul. 24/92
0.00B
0.00C
0.00D
J.McFadyen
J. McFadyen
MCH
2-11
Aug. 17/92
Oct. 22/92
0.01A
0.01B
MS
MS
Oct. 27/92
0.01C
MS
Nov. 8/92
0.01D
MS
All
Nov. 24/92
Jan. 22/93
July. 20/93
0.02
0.02
0.02
LA
MS
MS
All
vi,1-1,2-2
i,ii
All
1-1
2-1
Reason for Changes:
Renamed and relocated from
O:\DOCUMENT\OTHER\DOC0361.wp
to N:\APPL\P009 0FS.DL Reformatted
to WINC standards.
Corrected errors
Minor corrections
Reversed MSB and LSB in Figure 2-15
and accompanying text, as per J.
McFadyen.
Changed to meet IEC conventions
Re-added time-sync functionality to
Data Link and fixed a problem with
data frame duplication.
Added time-sync accuracy to TIME OF
DAY messages
Adopted fully-balanced transmission
procedures in order to become more
IEC compliant. Removed timesynchronization functions. Removed
Transport Functions section.
Reformatted to WI standards.
Added marketing comments
Removed IEC conformance section
from Chapter 2 and created new
Chapter 2. Renamed old chapter 2 to
Chapter 3.
Changed 'polling' to 'polled' in last
paragraph
Channel failover section changed 'was
intended to communicate' to
'communicates'
Date
Version
By Whom:
Pages
Affected:
2-2
2-3
2-5
2-7
2-9,2-10
2-11,2-12
2-14
2-15
2-20
2-21
2-23
3-1,3-2
4-4
G-1,G-2
Aug.30/93
0.02
Sept. 01/93 0.02
May 30/97 0.02
J.Bhat
All
AV
S. Tessari
All
All
Reason for Changes:
Paragraph 1 removed 'Chapter 2' of
line 2 to clarify sentence. Removed
paragraph 2 as it is confusing.
Paragraph 3, changed 'spontaneous' to
'unsolicited' and removed 'sub-master
station' references to make it easier to
follow. Paragraph, changed wording to
suggest 'compatible' schemes.
Paragraph 3, explained better.
USER DATA section explained that
there are 16 octets per block except
the last block (previously it was
unclear)
FCB, removed 'properly' from last
paragraph as it is meaningless. FCV
changed 'frame count bit valid bit' to
'frame count valid bit'
Simplified greatly
Simplified greatly
Defined CRC algorithm
Corrected error in diagram
Corrected spelling error
Removed misplaced graphic from page
and corrected error
Removed 'or will not' from line 4 as it is
misleading
Removed all references to
"configurable" parameters as this is
implementation specific. End of 3-2,
removed last sentence as it is
implementation specific.
Added 'DNP Data Link to Physical
Layer Implementation Issues
document' as a section of the Physical
Layer section in order to explain some
of the physical layer issues and usage
of the physical layer in the DNP data
link layer.
Removed some unneeded and
incorrect definitions
Checked for Grammar, Spelling,
Structure and Formatting
Revisions as per C. Heune.
Converted to MSWord 6.0.
DNP Users Group
DNP PRODUCT DOCUMENTATION
DNP V3.00
DATA LINK LAYER
Document Version: 0.02
Internal File: P009-0PD.DL
Associated Software Release: DNP V3.00
NOTICE OF RIGHTS - DNP USERS GROUP
The contents of this manual are the property of the DNP Users Group.
Revisions or additions to the definition and functionality of the
Distributed Network Protocol cannot be made without express written
agreement from the DNP Users Group or its duly authorized party. In
addition, no part of this document may be altered or revised or added to
in any form or by any means, except as permitted by written agreement
with the DNP Users Group or a Party duly authorized by the DNP Users
Group.
As a Party, duly authorized by the DNP Users Group, Harris
Corporation has made every reasonable attempt to ensure the
completeness and accuracy of this document, however, the information
contained in this manual is subject to change without notice, and does
not represent a commitment on the part of Harris Corporation or the
DNP Users Group. An update program for DNP documents is provided
upon request by Harris Corporation on behalf of the DNP Users Group.
TRADEMARK NOTICES
Brand and product names mentioned in this document are trademarks or
registered trademarks of their respective companies.
TABLE OF CONTENTS
ABOUT THIS DOCUMENT
PURPOSE OF THIS SPECIFICATION
WHO SHOULD USE THIS SPECIFICATION
HELP AND ADDITIONAL DOCUMENTATION
HOW THIS SPECIFICATION IS ORGANIZED
CONVENTIONS USED IN THIS SPECIFICATION
v
v
v
v
vi
vi
1. OVERVIEW
1-1
2. IEC CONFORMANCE
2.1 CHANNEL FAILOVER
2.2 FRAME FORMAT AND PROCEDURES
2.3 LENGTH, CONTROL AND ADDRESS FIELDS
2-1
2-1
2-1
2-2
3. DNP DATA LINK DESCRIPTION
3.1 PURPOSE OF THE DATA LINK LAYER
3.2 FT3 FRAME FORMAT
3.3 DATA LINK HEADER FRAME FIELDS
3.4 USER DATA
3.5 CRC FIELDS
3.6 DATA LINK FUNCTION CODES
3.7 TRANSMISSION PROCEDURES
3-1
3-1
3-1
3-2
3-6
3-6
3-7
3-10
4. DATA LINK SERVICES AND RESPONSIBILITIES
4.1 DATA LINK FUNCTIONS
4.2 INTERFACE DESCRIPTION
4-1
4-1
4-2
5. PHYSICAL LAYER INTERFACE
5.1 PHYSICAL LAYER DESCRIPTION
5-1
5-1
6. PHYSICAL LAYER CHARACTERISTICS
6.1 LINE CONFIGURATIONS
6.2 MODES OF TRANSMISSION
6.3 LOCAL LOOP
6-1
6-1
6-1
6-2
DNP V3.00 Data Link Layer (Version 0.02)
i
7. PHYSICAL LAYER PROCEDURES
7.1 GENERAL CONSIDERATIONS
7.2 HALF-DUPLEX PROCEDURES
7.3 FULL-DUPLEX PROCEDURES
7-1
7-1
7-1
7-2
LIST OF ABBREVIATIONS AND ACRONYMS
ii
DNP Users Group
TABLE OF FIGURES
FIGURE 3-1 FT3 FRAME FORMAT
3-2
FIGURE 3-2 CONTROL OCTET BIT DEFINITIONS
3-3
FIGURE 3-3 TABLE OF PRIMARY AND SECONDARY FUNCTION CODES
3-5
FIGURE 3-4 DESTINATION ADDRESS FORMAT
3-5
FIGURE 3-5 SOURCE ADDRESS FORMAT
3-5
FIGURE 3-6 CRC ORDERING
3-7
FIGURE 3-7 RESET OF SECONDARY LINK
3-10
FIGURE 3-8 RESET OF USER PROCESS
3-11
FIGURE 3-9 SEND FROM STATION A/CONFIRM FROM STATION B
3-11
FIGURE 3-10 SEND FROM STATION B/CONFIRM FROM STATION A
3-11
FIGURE 3-11 SEND MULTIPLE FRAMES FROM STATION A/CONFIRM FROM
STATION B
3-12
FIGURE 3-12 FRAME COUNT BIT OPERATION
3-12
FIGURE 3-13 FRAME COUNT BIT OPERATION
3-13
FIGURE 3-14 SEND-NO-REPLY EXPECTED FROM STATION A
3-13
FIGURE 3-15 SEND FROM STATION B/NACK FROM STATION A
3-14
FIGURE 3-16 REQUEST/RESPOND FRAME AND DFC BIT USAGE
3-15
DNP V3.00 Data Link Layer (Version 0.02)
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DNP Users Group
ABOUT THIS DOCUMENT
PURPOSE OF THIS SPECIFICATION
This document specifies the Distributed Network Protocol (DNP) Data Link layer
services, transmission procedures and Link Protocol Data Unit.
WHO SHOULD USE THIS SPECIFICATION
This specification is intended for communication engineers and programmers interested
in knowing the function and message format of the DNP data link layer. This includes
programmers implementing and designing DNP data link layer software/hardware and
quality assurance personnel testing and verifying implementations of the DNP data link
layer. Application programmers may find this specification useful in determining how to
interface with and make use of the DNP data link layer. Familiarity with the ISO-OSI 7layer model, IEC 3-layer EPA and IEC TC-57 standards is helpful.
HELP AND ADDITIONAL DOCUMENTATION
The following documentation may be helpful.
• IEC 870-5-1 and IEC 870-5-2 standards (or drafts), Technical Committee No. 57 for
data transmission in telecontrol systems
• DNP V3.00 Data Object Library (P009-0BL)
• DNP V3.00 Application Layer (P009-0PD.APP)
• DNP V3.00 Transport Functions (P009-0PD.TF).
DNP V3.00 Data Link Layer (Version 0.02)
v
HOW THIS SPECIFICATION IS ORGANIZED
1. OVERVIEW
A general overview of the data link layer.
2. IEC CONFORMANCE
Details the differences between DNP and the IEC TC-57 standards.
3. DNP DATA LINK DESCRIPTION
Describes the DNP data link frame format, function codes and procedures.
4. DATA LINK SERVICES AND RESPONSIBILITIES
Describes the services that the data link provides to higher layers.
5. PHYSICAL LAYER INTERFACE
Describes the service interface provided by the physical layer to the data link.
6. PHYSICAL LAYER CHARACTERISTICS
Describes the physical layer used with the DNP data link.
7. PHYSICAL LAYER PROCEDURES
Describes how the DNP data link uses the physical layer.
LIST OF ABBREVIATIONS AND ACRONYMS
CONVENTIONS USED IN THIS SPECIFICATION
In this document, the octet is a term used to refer to an eight bit data object and is
synonymous with the term byte. The low order bit of an octet is referred to as bit 0 and
the high order bit as bit 7.
Irregular capitalization is used in referencing technical terms which have an associated
verb or noun. For example, data link indications commonly referred to as IND, can also
be described using the word INDication.
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DNP Users Group
1. OVERVIEW
This document defines the Distributed Network Protocol (DNP) V3.00 Data Link layer,
Link Protocol Data Unit (LPDU), as well as data link layer services and transmission
procedures. Master stations, submaster stations, outstations and intelligent electronic
devices (IEDs) can use this data link to pass messages between primary (originating)
stations and secondary (receiving) stations. In this protocol, master stations, submaster
stations, outstations and IEDs are both originators (primary stations) and receivers
(secondary stations).
The IEC 870-5-1 and IEC 870-5-2 standards set out by the International Electrotechnical
Commission (IEC), Technical Committee No. 57 for data transmission in telecontrol
systems were used as a basis for developing the DNP V3.00 Data Link layer.
The DNP V3.00 Data Link layer supports polled and quiescent telecontrol systems and is
designed to operate with connection and connection-less orientated, asynchronous or
synchronous bit-serial physical layers such as RS-232C, RS-485 and fibre transceivers.
Fully-balanced transmission procedures were adopted to support spontaneous
transmissions from outstations, IEDs or submaster stations not designated as master
stations.
The ISO OSI based model supported by this protocol specifies physical, data link and
application layers only. This is termed the Enhanced Performance Architecture (EPA).
However, to support advanced RTU functions and messages larger than the maximum
frame length as defined by the IEC document 870-5-1, the DNP Version 3 Data Link is
intended to be used with a pseudo-transport layer which implements as a minimum
message assembly and disassembly.
This pseudo-transport layer is described in the document, DNP V3.00 Transport
Functions (P009-0PD.TF). It is stressed, however, that these transport functions are not a
part of the data link but are needed to support advanced RTU functions.
DNP V3.00 Data Link Layer (Version 0.02)
1-1
2. IEC CONFORMANCE
This chapter describes the difference between the DNP protocol and the IEC TC-57 (8705) telecontrol data link layer protocol specification.
2.1 CHANNEL FAILOVER
The DNP link layer communicates with only one physical layer (or channel). In the OSI
model, the Session layer is responsible for maintaining channel connections. In DNP, the
layer above the data link is responsible for providing channel failover based on
communications failure at the Data Link. This layer could be a Network/Transport Layer
or the Application Layer. Thus, the IEC requirement, 870-5-1, item 13, for channel
failover is met at the Application Layer.
2.2 FRAME FORMAT AND PROCEDURES
The data link layer uses a standard variable length frame format as defined in the IEC
870-5-1 Transmission Frame Formats document. The FT3 frame format class is well
suited for data transmission between stations that require medium information transfer
rates and low residual error probability. The basic frame format is used and transmission
rules R1, R2, R3 and R4 are followed. Rules R5 and R6 are followed in principle,
although the exact time values suggested are not used but are configurable in each
implementation. The frame definitions outlined in IEC 870-5-2 are followed with the note
that the Address field is 2 octets in length and specifies the destination station address and
the Link User Data field is used as a 2 octet source station address.
Fully-balanced transmission procedures as specified by IEC 870-5-2 were adopted to
handle unsolicited transmissions from stations not designated as masters in a half-duplex
or full-duplex system. Fully-balanced means that each station can act as a primary station
(sending) and a secondary station (receiving) at the same time. This configuration
requires a full-duplex channel to operate properly. In a half-duplex environment, the same
procedures will be used except that a station cannot be both a primary and secondary
station at the same time. That is, an entire data link layer transaction between the master
station and outstation will have to be completed at both stations before any further
transactions can be started from either station. In both half-duplex and full-duplex
configurations, it is the responsibility of each device to implement a compatible collision
avoidance scheme.
DNP V3.00 Data Link Layer (Version 0.02)
2-1
2.3 LENGTH, CONTROL AND ADDRESS FIELDS
The DNP data link uses the same LENGTH field as defined in IEC 870-5-1 clause 6.2.4.
(Refer to Section 3 for more information on this field).
The CONTROL field used is the IEC CONTROL field used for balanced transmission as
defined in IEC 870-5-2 clause 6.1.2. All the function codes specified in IEC 870-5-3
clause 6.1.2 Table III are supported.
The ADDRESS field is a 16-bit (2 octet) field. The DNP data link frame header has two
IEC ADDRESS fields. The first field is the A (Address) field where it is used to represent
the destination station address and the second is in the Link User Data field where it is
used to represent the source station address. (Refer to Section 3 for more information on
these fields).
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DNP Users Group
3. DNP DATA LINK DESCRIPTION
The Data Link Layer is the second layer in the Open System Interconnection (OSI)
model. The data link layer accepts, performs and controls transmission service functions
required by the higher layers.
3.1 PURPOSE OF THE DATA LINK LAYER
The main purpose of the DNP data link layer is twofold. First, the data link layer must
provide transfer of information or Link Service Data Unit (LSDU) across the physical
link as described by the ISO-OSI standard. This means that user data supplied by higher
layers (LSDU) must be converted into one frame (or LPDU as described in Section 2) and
sent to the physical layer for transmission. Conversely, individual LPDUs received by the
data link layer must be assembled into one LSDU and passed to higher layers. The layer
provides for frame synchronization and link control.
Secondly, in DNP V3.00, the data link provides indications of other events such as link
status.
The OSI reference model enforces either a connection-less or a connection oriented
system. However, the EPA model implies neither a connection-less system nor a
connection oriented system. The DNP Version 3 implementation of the IEC data link
handles both connection-less and connection oriented systems (that is, physical networks
that require dialing or logging in before data can be transmitted to the destination device)
but has no need to provide connection services. The actual physical network is
transparent to the application using the data link because the data link layer is responsible
for connecting and disconnecting from any physical network without higher level
interaction (i.e. application layer). That is, the data link (given the station destination
address) will connect to the right physical circuit without control supplied from higher
layers. In this way, the physical medium is totally transparent to the link layer service
user.
3.2 FT3 FRAME FORMAT
This section describes the LPDU format. An FT3 frame is defined as a fixed length
header block followed by optional data blocks. Each block has a 16-bit CRC appended to
it. The IEC specifies that the header fields consist of 2 start octets, 1 octet length, 1 octet
control, a destination address and an optional fixed length user data field. In this
implementation the fixed length user data field is defined as a source address.
DNP V3.00 Data Link Layer (Version 0.02)
3-1
•<•••••••••••••••••••••••••••• Block 0 ••••••••••••••••••••••••>•<- Block 1 ->•
•••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••
• START • START • LENGTH • CONTROL • DESTINATION • SOURCE • CRC • USER • CRC • ...
• 0x05 • 0x64 •
•
•
•
•
• DATA •
•
•••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••
•<••••••••••••••••••• Fixed Length Header •••••••••••••••••••••>•<•••••••••••• Body
10 octets
START
LENGTH
CONTROL
DESTINATION
SOURCE
CRC
USER DATA
|<- Block n ->|
------------| USER | CRC |
| DATA |
|
------------------------->|
2 starting octets of the header (0x0564).
1 octet count of USER DATA in the header and body. This count
includes the CONTROL, DESTINATION and SOURCE fields in
the header. The CRC fields are not included in the count. The
minimum value for LENGTH is 5 indicating only the header is
present and the maximum value is 255.
Frame control octet.
2 octet destination address. The first octet is the LSB and the
second octet is the MSB.
2 octet source address. The first octet is the LSB and the second
octet is the MSB.
2 octet Cyclic Redundancy Check.
Each block following the header has 16 octets of User defined data
except the last block of a frame which contains 1 to 16 octets of
User defined data as needed.
Figure 3-1 FT3 Frame Format
3.3 DATA LINK HEADER FRAME FIELDS
This section describes block 0 (or header) of a data link frame.
3.3.1 Start
The Start field is 2 octets in length. The first octet is a 05 hexadecimal and the second
octet is a 64 hexadecimal.
3.3.2 Length
The length field is 1 octet in length and specifies the count of user octets in the frame.
The CONTROL, DESTINATION and SOURCE field sizes are included in this count.
The minimum value for this field is 5 and the maximum value is 255.
3.3.3 Control
The control field contains the direction of the frame, type of frame and flow control
information.
Figure 3-2 defines the fields of the control octet. Station A is defined as the designated
master station. Station B is not a master station. The primary station is the originator of
the message, the source of the message. The secondary station is the destination station.
3-2
DNP Users Group
•••••••••••••••••••••••••••••••••••••••••••••••••
•
• 1 • FCB • FCV •
•
•
•
• Primary to Secondary
• DIR • PRM •••••••••••••
FUNCTION CODE
•
•
• 0 • RES • DFC •
•
•
•
• Secondary to Primary
•••••••••••••••••••••••••••••••••••••••••••••••••
Bit 7
6
5
4
3
2
1
0
DIR
Physical transmission direction
1 = station A to station B
0 = station B to station A
PRM Primary Message
1 = frame from primary (initiating station)
0 = frame from secondary (responding station)
FCB
Frame count bit
FCV
Frame count bit valid
1 = Frame count bit is valid
0 = ignore frame count bit
DFC
Data flow control bit
RES
Reserved = 0
FUNCTION CODE
Defines the frame type, how the data link will handle the frame
Figure 3-2 Control Octet Bit Definitions
DIR
The direction bit indicates the physical direction of the frame with relation to the
designated master station. Station A is the master.
DIR = 1 indicates a frame from A to B
DIR = 0 indicates a frame from B to A
PRM The primary message bit indicates the direction of the frame in relation to the
initiating station.
PRM =1 indicates a frame from the initiating station
PRM =0 indicates a frame from the responding station.
FCB
The frame count bit is used for suppressing losses and duplication of frames to the
same secondary station. This bit toggles for each successful SEND-CONFIRM
service that is initiated by the same primary station and directed to the same
secondary station.
Initially before communications with a secondary station or after communication
failure, the primary station (in both the master station and outstation) must reset
the data link for each secondary station data link it wishes to communicate with.
This can be done once at data link start-up for all secondary stations or as needed.
DNP V3.00 Data Link Layer (Version 0.02)
3-3
Each secondary station, after data link start-up or transaction failure, must not
accept any primary SEND-CONFIRM messages with FCV set until a RESET
command has been received and a CONFIRM message sent.
FCV
The frame count valid bit enables the functioning of the FCB bit.
FCV =0 indicates the state of the FCB bit is ignored
FCV =1 indicates to a secondary station that the state of the FCB bit must be
checked against the state of the FCB bit of the last frame sent with the FCV bit
set.
DFC
The data flow control bit is used to prevent the overflowing of buffers in a
secondary station. The secondary station returns this bit set to a 1 if further SEND
of user data to this secondary station will cause data link buffers to over flow. The
primary station must interrogate the secondary station using REQUESTRESPOND Request Link Status until the DFC is returned with a value of 0. At
this point the primary station can continue with the sending of user data. Figure 316 illustrates the DFC bit usage.
FUNCTION CODE
The function code identifies the type of frame. The definition of
the values placed in this field are different between primary and
secondary stations. The following tables define the implemented
codes and associated FCV states.
Function Code Field Values of the Control Octet Sent from the Primary Station (PRM =
1)
•••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••
• Function •
Frame Type
•
Service Function
• FCV •
• Code
•
•
• Bit •
•••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••
•
0
• SEND - CONFIRM expected
• RESET of remote link
• 0 •
•
1
• SEND - CONFIRM expected
• Reset of user process
• 0 •
•
2
• SEND - CONFIRM expected
• TEST function for link
• 1 •
•
3
• SEND - CONFIRM expected
• User Data
• 1 •
•
4
• SEND - NO REPLY expected
• Unconfirmed User Data
• 0 •
•
5
•
• Not Used
• - •
•
6
•
• Not used
• - •
•
7
•
• Not Used
• - •
•
8
•
• Not Used
• - •
•
9
• REQUEST - RESPOND expected • REQUEST LINK STATUS
• 0 •
•
10
•
• Not Used
• - •
•
11
•
• Not Used
• - •
•
12
•
• Not Used
• - •
•
13
•
• Not Used
• - •
•
14
•
• Not Used
• - •
•
15
•
• Not Used
• - •
•
•
•
•
•
•
•
•
•
•
•••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••
3-4
DNP Users Group
Function Code Field Values of the Control Octet Sent from the Secondary Station (PRM
= 0)
•••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••
• Function • Frame Type •
Service Function
•
• Code
•
•
•
•••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••
•
0
• CONFIRM
• ACK - positive acknowledgement
•
•
1
• CONFIRM
• NACK - Message not accepted, Link busy
•
•
2
•
• Not Used
•
•
3
•
• Not Used
•
•
4
•
• Not Used
•
•
5
•
• Not Used
•
•
6
•
• Not Used
•
•
7
•
• Not Used
•
•
8
•
• Not Used
•
•
9
•
• Not Used
•
•
10
•
• Not Used
•
•
11
• RESPOND
• Status of Link (DFC = 0 or DFC = 1)
•
•
12
•
• Not Used
•
•
13
•
• Not Used
•
•
14
•
• Link service not functioning
•
•
15
•
• Link service not used or implemented
•
•••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••
Figure 3-3 Table of Primary and Secondary Function Codes
3.3.4 Destination Address
The Destination address field is 2 octets in size and specifies the address of the station
that the frame is directed to. The first octet of the address is the low order octet and the
second octet is the high order.
The address 0xffff is defined as an all stations address. All stations will accept frames
with the destination address set to this value.
•••••••••••••••••••••••••••••••••••••••••••••••••••••••••
•
•
•
•
LOW ORDER OCTET (LSB) •
HIGH ORDER OCTET (MSB) •
•
•
•
•••••••••••••••••••••••••••••••••••••••••••••••••••••••••
Figure 3-4 Destination Address Format
3.3.5 Source Address
The source address field is 2 octets in size and specifies the address of the station that the
frame originated from. The first octet of the address is the low order octet and the second
octet is the high order. Note that this field is not included as USER DATA but must be
passed as a return value to the higher layers by the data link service primitives.
•••••••••••••••••••••••••••••••••••••••••••••••••••••••••
•
•
•
•
LOW ORDER OCTET (LSB)
•
HIGH ORDER OCTET (MSB) •
•
•
•
•••••••••••••••••••••••••••••••••••••••••••••••••••••••••
Figure 3-5 Source Address Format
DNP V3.00 Data Link Layer (Version 0.02)
3-5
3.4 USER DATA
The blocks following the header may contain from 1 to 16 octets of user data. If more
than 16 user data octets follow the header (block 0), each block must contain 16 octets of
data except for the last block. The last block will contain the leftover. Each data block has
a CRC appended to it.
The data link layer passes all of the user data and the source address from the header to
the higher layers when a SEND user data frame is received. The data link service
primitives provide a place to put the source address.
3.5 CRC FIELDS
A two octet cyclic redundancy check is appended to each block in a frame. The START,
LENGTH, CONTROL, DESTINATION and SOURCE fields are all included when
calculating the CRC for the header.
The 2 octet CRC check is generated from the following polynomial and then inverted
before being placed in the block for transmission:
X16 + X13 + X12 + X11 + X10 + X8 + X6 + X5 + X2 + 1
The CRC algorithm used will now be described. In the following discussion, modulo-2
arithmetic (addition and division) is assumed. A message block (M) of k-bits is to be
transmitted (along with other blocks) (k is 64 for the header, 128 for all user data blocks
but the last block where k is 8 to 128). A 16-bit CRC check word (F) is bit-wise inverted
(F') and appended to M. Together M and F' are appended together so that T' = 216M + F'
and T' will be transmitted (additionally we define T = 216M + F). The CRC check
sequence is a pattern (P) of 17 bits as defined above in polynomial form. The CRC
algorithm requires that when T is divided by P at the receiver the remainder is 0. If the
remainder is not 0 then the block is in error. In addition, the remainder (R) of 216M/P is
used as F in the block so that 216M/P = Q + R/P (Equation. 1) (Q is the quotient). This
can be proven to provide a remainder of 0 as follows. If we assume that T=216M + R then,
T/P = (216M + R)/P. If we substitute equation 1 then T/P = Q + (R + R)/P = Q since R
added to itself modulo-2 results in zero.
The transmission and reception procedure is described below:
To transmit a block:
(1)Take the user data block M with k data bits.
(2)Multiply M by 216 to obtain 216M.
(3)Divide this number (module-2) by P (17-bits) to get R (16-bits).
(4)Invert R bit-wise to get R'.
(5)Append R' to 216M and transmit as a block (T').
3-6
DNP Users Group
To receive a block:
(1)Receive a block (T') (k+16 bits).
(2)Invert R'(16-bits) in T'(k+16 bits) to get T (k+16 bits).
(3)Divide T (module-2) by P (17-bits) to get the remainder.
(4)If the remainder is not 0 then there is an error in the block else the block is good.
Using the FT3 frame format class and CRC, the frame has a Hamming distance of 6.
The diagram below shows the ordering of the 16-bit CRC check word with respect to any
blocks (user data or header).
••••••••••••••••••••••••••••••••••••••••••••••••••••••
•
• LSB • MSB •
••••••••••••••••••••••••••••••••••••••••••••••••••••••
•
Block Octets
•
CRC
•
•
•
•
Figure 3-6 CRC Ordering
3.6 DATA LINK FUNCTION CODES
3.6.1 Reset
This function code is used to synchronize a primary and secondary station for further
SEND-CONFIRM transactions. Upon reception and reply to a RESET command, the
secondary station will begin accepting Primary messages from that Primary station with
the FCV bit set. The RESET command only enables communications in one direction,
from the primary to the secondary station. This is because a successful transaction only
guarantees that the primary station transmitter and the secondary station receiver are
communicating. The primary station must send this function code when it wishes to first
communicate with the secondary station or after a communications failure has been
recognized by the primary station. When a secondary station has re-started or when a
communications failure has been recognized by the secondary, the secondary station will
be considered un-reset. In this state, the secondary station will not accept messages from
the primary station until it has received and replied to a RESET command from that
primary station.
The RESET command also synchronizes the FCB bit between primary and secondary
stations. The secondary station after completing the RESET transaction will expect the
FCB bit in the next message (with FCV valid) to be 1 from that primary station. The
primary station after completing the RESET transaction will set the FCB bit to 1 in the
next message (with FCV valid) to that secondary station.
3.6.1.1 Primary Transaction
Do number of configurable tries: (i.e. retries + 1)
Send RESET frame with FCV=0, FCB=x, PRM=1, DIR=x
Wait the pre-determined time-out period for an ACK frame from the secondary station.
DNP V3.00 Data Link Layer (Version 0.02)
3-7
If ACK frame is received, set FCB status to 1 (i.e. next frame sent to secondary with FCV
valid should have FCB=1) and exit loop.
If frame is not received then go to top of loop and re-try
End do loop
If ACK was received then the transaction is considered successful and the secondary
station can be considered on-line. A positive INDication can be returned to the data link
user.
Otherwise, the secondary station should be considered off-line and a negative INDication
should be sent to the data link user.
3.6.1.2 Secondary Transaction
After start-up or after transaction failure do:
Wait for reception of RESET command with FCV=0, FCB=x, PRM=1, DIR=x.
Respond with an ACK confirm frame (DFC=x, PRM=0, DIR=x). The FCB status
(expected value of FCB in next received frame with FCV valid) should be set to 1. A
positive INDication can be sent to the data link user.
During normal operation, if a RESET command with FCV=0, FCB=x, PRM=1 and
DIR=x is received, then the current transaction (if any) can be aborted (possibly with
negative INDication sent to data link user).
In such case, respond with an ACK confirm frame (DFC=x, PRM=0, DIR=x). The FCB
status (expected value of FCB in next received frame with FCV valid) should be set to 1.
A positive INDication can be sent to the data link user.
3.6.2 Reset of User Process
This function code is used to reset the data link user process. Upon reception by a
secondary station, an INDication should be sent to the data link user. The data link user
can use this indication to reset its internal state. If accepted by the data link user, an ACK
confirm frame is sent in reply otherwise a NACK confirm frame is sent in reply.
3.6.3 Test
The TEST command is used to test the state of the secondary data link. Upon reception
by a secondary station, it checks the value of the FCB bit in the primary message and
compares it against the FCB status (expected FCB) for that primary station. If the FCBs
do not match, then the secondary station should send the last secondary confirm frame.
Otherwise, an ACK confirm frame should be sent in reply and the expected FCB status
should be toggled. The secondary station also sets the DFC bit accordingly in the
response.
3.6.4 User Data
3-8
DNP Users Group
The User Data function is used to send confirmed data to a secondary station. Before
communications can begin, the secondary station must have been RESET according to
the rules above (see RESET). The frame sent contains the user data from the primary data
link user that is to be passed to the data link user of the secondary station. The
transmission procedures are described below:
3.6.4.1 Primary Transaction
Do number of configurable tries: (i.e. retries + 1)
Send User Data frame with FCV=1, PRM=1, DIR=x and FCB set to FCB status for the
secondary station (next expected FCB status).
Wait the pre-determined time-out period for a ACK or NACK frame from the secondary
station.
If frame is NACK then wait a pre-determined amount of time until secondary link is NOT
busy or use REQUEST LINK STATUS (below) and go to top of loop to retry.
If correct ACK frame is received, toggle FCB status (i.e. next frame sent to secondary
with FCV valid should have opposite FCB) and exit loop.
If correct frame is not received then go to top of loop and re-try.
If ACK was received then the transaction is considered successful and the secondary
station can be considered on-line. A positive INDication can be returned to the data link
user.
Otherwise, a negative INDication should be sent to the data link user and the secondary
station can be considered off-line or on-line depending on the data link user's
interpretation of the failure.
3.6.4.2 Secondary Transaction
Upon reception of a User Data frame with FCV=1, PRM=1, DIR=x and FCB set to FCB
status (expected FCB state) do the following:
If the data link user is ready to accept user data then respond with an ACK confirm frame
(DFC=x, PRM=0, DIR=x) else respond with a NACK frame (same bit settings as ACK)
and exit this loop.
3.6.5 Unconfirmed User Data
This function is used to send user data to the secondary station without needing
confirmation. In this way, the bandwidth of the system can be more fully utilized if the
user data is low priority. The frame sent contains the user data from the primary data link
user that is to be passed to the data link user of the secondary station. The transmission
procedures are described below:
3.6.5.1 Primary Transaction
DNP V3.00 Data Link Layer (Version 0.02)
3-9
Send Unconfirmed User Data frame with PRM=1, DIR=x, FCV=0, FCB=x.
Announce positive INDication to data link user.
3.6.5.2 Secondary Transaction
Receive Unconfirmed User Data frame as above and send positive INDications with the
data to the data link user.
3.6.6 Request Link Status
This command is used to request the status of the secondary data link. A secondary
station will respond to this request with a LINK STATUS confirm frame with the DFC
bit set to 1 if the data link is busy or the data link user cannot accept any more user data
and 0 indicating that the data link is not busy and the data link user can accept more user
data. The transmission procedures are similar to TEST except that the primary station will
typically only use this command when a NACK frame is received during a User Data
transaction.
3.7 TRANSMISSION PROCEDURES
This section illustrates the usage of the defined frame types.
3.7.1 Reset of Secondary Link
In Figure 3-7, a primary station sends a SEND-CONFIRM RESET frame to a secondary
station. The secondary station receives the message and responds with an ACK confirm
frame.
Reset
(REQ)
(IND)
Positive
•••••••••••
•
•
• SEND
•
• FCB=0 •
••••••••••••••••••••••> ••••••••••••••• Expected FCB=x
• CONFIRM
•
<•••••••••••••••••••••••••••• (IND)
Reset
Next FCB=1
Expected FCB=1
Figure 3-7 Reset of Secondary Link
3.7.2 Reset of User Process
In Figure 3-8, a primary station sends a SEND-CONFIRM Reset User Process frame to a
secondary station. The secondary station receives the message and responds with an ACK
confirm frame.
3-10
DNP Users Group
Reset User
(REQ)
(IND)
Positive
•••••••••••
•
•
• SEND
•
•
•
••••••••••••••••••••••> •••••••••••••••
• CONFIRM
•
<•••••••••••••••••••••••••••• (IND)
Reset User
Figure 3-8 Reset of User Process
3.7.3 Send/Confirm User Data
In Figure 3-9, the designated master station acting as a primary station sends a SENDCONFIRM frame to a non-master station acting as a secondary station. This is the first
frame with FCV valid after the secondary link was reset (above) so FCB = 1 in the SEND
frame. The secondary station expects FCB to be 1 since this is the first frame (with FCV
valid) after the link was reset (above) and sends a CONFIRM frame. The master station
upon receiving the CONFIRM assumes the message was correctly received and
INDicates success to the master station data link user.
STATION A
(REQ)
STATION B
•••••••••••••
•
•
• SEND
•
• FCB=1
•
••••••••••••••••••••••••> •••••••••••••••
• CONFIRM
•
•
•
<••••••••••••••••••••••••••••
(IND)
Positive
Expected FCB=1
(IND)
Data
Figure 3-9 SEND From Station A/CONFIRM From Station B
In Figure 3-10, a non-master station acting as a primary station sends a SEND-CONFIRM
frame to a designated master station acting as a secondary station. Since this is the second
frame after the secondary link has been reset the FCB = 0 in the SEND frame. The
secondary expects FCB to be 0 since this is the second frame received after the link was
reset. A CONFIRM frame is sent in response. The non-master station upon receiving the
CONFIRM INDicates success to the non-master station data link user.
••••••••••••
•
•
•
SEND
•(REQ)
Expected FCB=0
• FCB=0
•
•••••••••••••••<••••••••••••••••••••••••
• CONFIRM
•
•
•
••••••••••••••••••••••••••>
(IND) Positive
(IND) User Data
Figure 3-10 SEND From Station B/CONFIRM From Station A
DNP V3.00 Data Link Layer (Version 0.02)
3-11
In Figure 3-11, a designated master station sends 3 consecutive frames to the same nonmaster station.
(REQ 1)
•••••••••••
• SEND
•
• FCB=1 •
••••••••••••••••••••••> •••••••••••••
• CONFIRM •
•
•
(IND) Positive
<•••••••••••••••••••••••••
(REQ 2)
•••••••••••
• SEND
•
• FCB=0 •
••••••••••••••••••••••••>
•••••••••••••
• CONFIRM •
•
•
(IND) Positive
<•••••••••••••••••••••••••
(REQ 3)
•••••••••••
• SEND
•
• FCB=1 •
••••••••••••••••••••••••>
•••••••••••••
• CONFIRM •
•
•
(IND) Positive
<•••••••••••••••••••••••••
Expected FCB=1
(IND) User Data
Expected FCB=0
(IND) User Data
Expected FCB=1
(IND) User Data
Figure 3-11 SEND Multiple Frames From Station A/CONFIRM From Station B
In Figure 3-12, the designated master acting as primary sends a one frame message to the
secondary non-master. This example illustrates what happens when the CONFIRM from
the secondary station is lost.
•••••••••••
•
•
• SEND
•
• FCB=1 • t DAB
•••
••••••••••••••••••••••> •••••••••••••
•
t DBA
• CONFIRM •
•
•
•
•
garbled
•••••••••••••••••••••••••••
•
or not received
retry delay > t DAB + t DBA + t CONFIRM duration
•
•••
•••••••••••
•
•
(same data)• SEND
•
• FCB=1 •
••••••••••••••••••••••> •••••••••••••
•
•
• CONFIRM •
•
•
<•••••••••••••••••••••••••
(IND) Positive
(REQ)
Expected FCB=1
(IND) User Data
+ t SEND message processing time at station B
Expected FCB = 0
send data is ignored, unexpected FCB
but another confirm is sent
Figure 3-12 Frame Count Bit Operation
In Figure 3-13, the designated master acting as primary sends a two frame message to the
secondary non-master. This example illustrates what happens when the SEND frame
from the primary station is lost.
3-12
DNP Users Group
•••••••••••
•
•
• SEND
•
Expected FCB = 0
• FCB=0 •
••••••••••••••••••••••> •••••••••••••
• CONFIRM •
tBA •
•
(IND) Positive•••••••••••<••••••••••••••••••••••••• (IND) User Data
• SEND
•
• FCB=1 • tAB
•••••••••••••> (lost or garbled)
(REQ)
retry delay > tBA + tAB + CONFIRM time + CONFIRM processing time at Station B
•••••••••••
• SEND
•
• FCB=1
•
Expected FCB=1
••••••••••••••••••••••> •••••••••••••
• CONFIRM •
•
•
(IND) Positive ••••••••• <••••••••••••••••••••••••• (IND) User Data
Figure 3-13 Frame Count Bit Operation
NOTE:
Both a master station and non-master station acting as primary stations can
re-try SEND frames.
3.7.4 Send/No Reply Expected
In Figure 3-14, the master or non-master primary station sends 3 frames to the secondary
master or non-master. Upon successfully transmitting the SEND frame, the primary
station INDicates success to the data link user. The secondary station, upon reception of a
valid frame INDicates data availability to the data link user.
(REQ)
•••••••••••••
• SEND
•
• NO REPLY •
•
•
••••••••••••••••••••••••> (IND) Positive with user data
•••
•
delay before next frame = t SEND message processing at station B
•
•••
•••••••••••••
(REQ 2)
• SEND
•
• NO REPLY •
•
•
••••••••••••••••••••••••> (IND) Positive with user data
•••
•
delay
•
•••
•••••••••••••
(REQ 3)
• SEND
•
• NO REPLY •
•
•
••••••••••••••••••••••••> (IND) Positive with user data
Figure 3-14 SEND-NO-REPLY Expected From Station A
3.7.5 Send/NACK
In Figure 3-15, a non-master primary station sends a frame to the master secondary. Upon
reception of the first CONFIRM, the primary INDicates success to the data link user. The
DNP V3.00 Data Link Layer (Version 0.02)
3-13
primary sends a second frame to the secondary. The secondary master decides that it
cannot accept any frames at this time and sends a NACK frame back. The primary, after
receiving this NACK, will fail the transaction and send a negative INDication to the data
link user.
•••••••••••
•
SEND •
• FCB=1 •
•••••••••••••<•••••••••••••••••••••••
• CONFIRM •
•
•
(IND) Positive ••••••••••••••••••••••••>
•••••••••••
• SEND
•
• FCB=0 •
•••••••••••••••••••••••••••••••••••••
•
NACK
•
••••••••••••••••••••••••>
(IND) Negative
(REQ 1)
Expected FCB=1
(IND) Positive
(REQ 2)
(IND) Negative
Figure 3-15 SEND From Station B/NACK From Station A
3.7.6 Request/Respond
In Figure 3-16, a primary station SENDs consecutive frames to a secondary station. When
the secondary station cannot receive any more frames, the CONFIRM message contains
the DFC bit set. The primary station will, upon reception of the CONFIRM, stop
SENDing data frames to the secondary station but will instead periodically REQUEST
the status of the secondary by sending a REQUEST-RESPOND frame. The secondary
will RESPOND to the REQUEST frame with the current state of the DFC. If the
secondary is ready to receive more data, the DFC returned will be 0 otherwise the DFC
returned will be 1. When the primary station recognizes DFC = 0 in the RESPOND
frame, the transmission of SEND frames will continue.
3-14
DNP Users Group
(REQ 1)
(IND) Positive
Receipt of CONFIRM frame
with DFC = 0 is the
condition for
transmission of the next
SEND user data frame.
(IND) Positive
(REQ 3)
Receipt of CONFIRM frame
with DFC = 0 is the
condition for
transmission of the next
SEND user data frame.
•••••••••••••
•
•
•
SEND
•
•
FCB=0
•
••••••••••••••••••••••••> •••••••••••••
• CONFIRM •
• DFC=0
•
•••••••••••••<•••••••••••••••••••••••••
• SEND
•
•
•
• FCB=1
•
••••••••••••••••••••••••> •••••••••••••
• CONFIRM •
• DFC=1
•
•••••••••••••<•••••••••••••••••••••••••
• REQUEST •
• RESPOND •
•
•
••••••••••••••••••••••••> •••••••••••••
• CONFIRM •
• DFC=1
•
•••••••••••••<•••••••••••••••••••••••••
• REQUEST •
• RESPOND •
•
•
••••••••••••••••••••••••> •••••••••••••
• CONFIRM •
•
DFC=0
•
•••••••••••••••••••••••••••••••••••••••
• SEND
•
•
•
• FCB=0
•
••••••••••••••••••••••••> •••••••••••••
• CONFIRM •
• DFC=0
•
<•••••••••••••••••••••••••
(IND) User Data
(IND) User Data
but buffers full now
(IND)
(IND) User Data
Figure 3-16 REQUEST/RESPOND Frame and DFC Bit Usage
DNP V3.00 Data Link Layer (Version 0.02)
3-15
4. DATA LINK SERVICES AND
RESPONSIBILITIES
4.1 DATA LINK FUNCTIONS
This section describes the services offered by the data link and its functions. The
communication requirements of the network layer and the pseudo-transport layer are
satisfied by the data link layer service primitives.
The data link is responsible for performing the following functions:
• Performing message retries
• Synchronizing and handling of the FCB bit in the control word
• Setting and clearing the DFC bit based on buffer availability
• Automatically establishing a connection based on the destination parameter in a dial
up environment when a directed service is requested by the user
• Disconnection in a dial-up environment
• Packing user data into the defined frame format and transmitting the data to the
physical layer
• Unpacking the frames that are received from the physical layer into user data
• Controlling all aspects of the physical layer
• Performing collision avoidance/detection procedures to ensure the reliable transfer of
data across the physical link
• Responding to all valid frames (function codes) received from the physical layer.
The data link is responsible for providing the following services:
• Exchange of SDUs between peer DNP data links
• Error notification to data link user
• Sequencing of SDUs
• Prioritized SDU delivery
• Quality SDU delivery.
SDUs will only be exchanged between peer DNP data links.
Priority delivery can be EXPEDITED or NORMAL to indicate a high or low priority
request.
DNP V3.00 Data Link Layer (Version 0.02)
4-1
Quality delivery can be SEND-NO-REPLY or SEND-CONFIRM to indicate whether or
not message acknowledgment is required.
Error notification will be given to the data link user when a response to a request has not
been received.
4.2 INTERFACE DESCRIPTION
The data link service primitives are illustrated in pseudo code to illustrate the
requirements and behavior in a real implementation and are not intended as an exact
interface definition.
Data link request (REQ) services can be used at any time after the data link has been
initialized and configured by the system.
confirm = request_data_link_service(
SERVICE,
TIME_SERVICE,
destination,
source,
send_data_buffer,
send_count,
retry_flag,
time_of_transmission
)
Input:
SERVICE
Service to perform
TIME_SERVICE
Guaranteed time service to perform
source Source address to use in sent message
destination
Destination address to use in sent message
send_data_buffer
Data to send in message
send_count Number of octets in message
retry_flag
Instructs data link layer to retry unacknowledged frames or not
time_of_transmission Time that first bit of first octet of message is to be sent
Output:
time_of_transmission Time that first bit of first octet of message was sent
4-2
DNP Users Group
Confirm =
0
1
2
3
4
Service =
0
1
2
3
4
Time_service 0
1
Requested service was successful
Requested service has failed
Requested SEND data service was terminated by the current
primary station. (reception of a NACK frame from the secondary
station)
Service code is not implemented
Requested service cannot proceed at this time because the data link
is busy either with a previous requested transaction, current
unrequested transaction or waiting for physical layer availability
Send a message specified in parameters using SEND-CONFIRM
frames. Fails if the data link is busy
Send a message specified in parameters using SEND-NO- REPLY
frames. Fails if the data link is busy
Expedited send a message specified in parameters using SENDCONFIRM frames. May necessitate cancelling the current
secondary transaction if a half-duplex system is used (i.e. forces the
data link to send a NACK frame instead of a CONFIRM frame in
the next secondary transaction). This action only takes place if the
primary station is using SEND-CONFIRM frames.
Expedited send a message specified in parameters using SENDNO-REPLY expected frames. In a half-duplex system, this may
mean cancelling the current secondary transaction (as above).
Return link status. Return successful if the data link is not busy.
Send message at time specified in time_of_transmission. This
service should have the highest priority.
Send message at any time with priority specified.
Data link indications (IND) can be requested at any time by the service user but should be
checked as often as possible in order to obtain received data.
indications = request_data_link_indications(
source_address,
destination_address,
received_data_buffer,
received_data_count,
time_of_reception)
Output:
source_address
destination_address
received_data_buffer
received_data_count
time_of_reception
Source address of received message
Destination address of received address
Received message
Number of octets in message
Time at which first bit of first octet of message was received
DNP V3.00 Data Link Layer (Version 0.02)
4-3
Indications = 0
1
2
4-4
No indications to report
Data link has received a valid message that has been placed in
received_data_buffer and the number of octets received has been
placed in received_data_count. The source address of the received
message has been placed in source_address. If the data link is
configured as a master station then the time that the first bit of the
first octet of the message was received has been placed in
time_of_reception. If the data link is configured as an outstation
then the time_of_reception will still be returned but the service
user has to be aware of the possibility of inaccurate times received
before the outstation has been time-synchronized.
Data link has detected a transaction failure.
DNP Users Group
5. PHYSICAL LAYER INTERFACE
This section describes the DNP Version 3 Data Link to physical layer interface. The
interface describes the necessary services that ANY physical layer must provide in order
to accommodate the DNP V3.00 Data Link.
5.1 PHYSICAL LAYER DESCRIPTION
The physical layer that is recommended for the data link is a bit-serial oriented
asynchronous physical layer supporting 8 bit data, 1 start bit, 1 stop bit, no parity and RS232C voltage levels and control signals. The CCITT V.24 standard describes the DTE
(Data Terminal Equipment) which is used for communication with a DCE (Data
Communication Equipment) and is usually a frequency-switched modem (FSK). This
type of circuit connection to a PSN (Public Switching Network) or to private leased lines
can be used. In each case, the appropriate modem must be used and must conform
(minimally) to the V.24 standard DCE definition.
The physical layer must provide 5 basic services: Send, Receive, Connect, Disconnect,
and Status. The Send service converts data octets into bit-serial data for transmission
between the DTE and DCE. It must provide the proper signal control in order to
communicate with the given DCE. The Receive service must be able to accept data from
the DCE and therefore provide the correct signaling to the DCE in order to receive data
and not noise. The Connect and Disconnect services provide connection and
disconnection from the PSN (if applicable). The Status service must be able to return the
state of the physical medium. As a minimum, the service must indicate whether or not the
medium is busy.
The physical link service primitives are illustrated in pseudo code to illustrate the
requirements and behavior in a real implementation and are not intended as an exact
interface definition.
Physical layer requests can be sent at any time after the physical layer has been started
and configured with all relevant parameters.
confirm = request ( SERVICE,
data_buffer,
data_count,
modem_string,
time_of_transmission)
DNP V3.00 Data Link Layer (Version 0.02)
5-1
Input:
data_buffer Data to send
data_count
Number of octets to send
modem_string Command string for DCE
Output:
time_of_transmission Time that first bit of first octet of message was transmitted
Confirm =
0
1
2
3
Requested service was successful
Requested service has failed
Service code is not implemented
Requested service cannot proceed at this time because the physical
link is busy either with a previous requested transaction, current
unrequested transaction or waiting for DCE availability
Service =
0
Send a message specified in data_buffer of size specified in
data_count
Initialize DCE using string specified in modem_string
Connect to PSN using string specified in modem_string
Disconnect from PSN
Request physical link status, returns 0 if busy and 1 if not busy
1
2
3
4
Physical layer indications (IND) can be requested at any time by the service user but
should be checked as often as possible in order to obtain received data.
indications = indicate(received_data_buffer,
received_data_count,
time_of_reception)
Output:
received_data_buffer Received message
received_data_count Number of octets in message
time_of_reception
Time at which first bit of first octet of message was received
Indications =
0
1
2
3
4
5-2
No indications to report.
Physical layer has received a message that has been placed
in received_data_buffer and the number of octets received
has been placed in received_data_count.
DCE has connected to PSN (incoming call).
DCE has disconnected from PSN (hang up).
Physical layer has detected problems with the link or DCE
that makes communication inadvisable or impossible until
some later time. Re-initialization of the DCE may be
required.
DNP Users Group
6. PHYSICAL LAYER
CHARACTERISTICS
6.1 LINE CONFIGURATIONS
Regardless of the physical layer used, there are two physical topologies used to construct
a SCADA communications network. These are direct and serial bus topologies.
The direct topology has two physical nodes with each physical node connected directly to
the other. This is often referred to as point-to-point and can be a direct physical cable
from point-to-point, a two node radio or modem network or a dial-up connection through
a PSN (Public Switched Network).
The serial bus topology has more than two physical nodes with each node connected to
the same channel or communication line as every other node in the serial bus network.
This is often referred to as a multi-drop configuration and is commonly made up of many
Bell 202 modems with their outputs/input tied together. In this configuration, there is one
node which is deemed to be in control of the physical network. This is often the SCADA
master. This node transmits to multiple-nodes and receives from multiple nodes. All other
nodes in the bus receive from the master node and transmit to the master node.
The DNP data link supports multiple-master, multiple-slave and peer-to-peer
communications.
In peer-to-peer communications, all devices act as slave data links and collision
avoidance should be turned on as no one device has a higher priority and all can transmit
spontaneously.
In a multiple-master configuration, the master devices are higher priority than the slave
devices. However, priority has to be assigned amongst the masters.
6.2 MODES OF TRANSMISSION
The physical layer supported by DNP must transmit/receive data in serial mode.
Generally, the data unit transferred will be 8 bits in length. The transmission can be
asynchronous, synchronous or isochronous allowing for higher throughput with a
DNP V3.00 Data Link Layer (Version 0.02)
6-1
synchronous modem. The actual mechanism used has no affect on the operation of the
data link.
6.3 LOCAL LOOP
The termination of the data communications circuit at the communication node (i.e. NOT
at the modem) can be accomplished using a two-wire or four-wire circuit (i.e. TX/RX
pair or independent TX and RX pairs).
The DNP data link can use half-duplex procedures with a 2-wire circuit and full-duplex
or half-duplex procedures with a 4-wire circuit.
The DNP data link can support both full-duplex and half-duplex procedures at the local
loop. Both cases, however will be handled quite differently.
6-2
DNP Users Group
7. PHYSICAL LAYER PROCEDURES
7.1 GENERAL CONSIDERATIONS
The purpose of the data link to physical layer interface is to allow the data link to send or
receive a message to or from another data link. To accomplish this, the data link must be
able to control when the transmission of data takes place, detect the presence of data on
the physical communication circuit and use control line signaling for control of the
physical circuit. In addition, the master station (or highest priority device) needs to be
able to take control of the communication circuit and block other stations from
transmitting.
In a direct connection type topology, the primary station (initiating station) can only
communicate with one station. If this circuit is four-wire then full-duplex procedures will
be used and there will be no chance of message collisions on the circuit. However, if the
circuit is two-wire then half-duplex procedures will be used. In this case, a collision can
occur if both stations attempt to transmit data at the same time. A direct connect to a dialup PSN is typically 2-wire but the circuit from the station to the modem is a 4-wire fullduplex circuit and should be used in a full-duplex fashion. The dial-up modem must use
CTS to hold off the transmitter after RTS is asserted.
In a multi-drop topology, the designated master station can act as a primary station to
many secondary stations. In this case there is a chance of collision in a two-wire or four
wire circuit.
In a two-wire circuit, the designated master station messages can collide with any other
stations message and the slave station messages can collide with each other at any time.
In a four wire circuit, the master station messages cannot collide with the slave station
messages but the slave station messages can collide with each other.
7.2 HALF-DUPLEX PROCEDURES
When half duplex procedures are used in a two-wire system, there are several ways to
avoid or recover from a collision on the communication circuit. Regardless of the
physical layer used, all physical layers should be able to return a data carrier detection
indication (DCD) which indicates if there is traffic on the circuit. In a two-wire system,
the indication appears when the master or slave is transmitting on the circuit. When this
DNP V3.00 Data Link Layer (Version 0.02)
7-1
indication is present, a station is transmitting on the circuit. During this time, no other
station should attempt to transmit on the circuit. When the indication disappears, the
circuit is free for someone to use. The question now is, which station is allowed to
transmit on the circuit.
In the point-to-point configuration, either the master or slave station could transmit. In the
multi-drop configuration, either the master or any of many slave stations could transmit.
The DNP data link protocol does not assign priority to either the master or slave message
but it is generally accepted in SCADA that the master should have control of the
communication circuit and therefore should transmit the message (if one is to be sent).
Any slave station, if allowed to transmit at this point, could possibly cause a collision so
the slave station must wait some time after detecting the loss of a data carrier before
attempting to send. Before sending, the indication is checked again and if the circuit is
still idle then the transmission can take place. If the circuit is busy then the station must
wait again until the indication disappears and perform the procedure again. The insertion
of the time delay after the loss of data carrier allows the master to take control of the
circuit (if needed at that time) and shuts out the other station (because the carrier
indication is caused by the masters transmission).
7.2.1 Point-to-Point
In a point-to-point configuration this time delay only needs to be as long as the time
needed for the master to detect the loss of data carrier and begin the transmission of the
message (plus any propagation delays in the system) (Master_min time).
7.2.2 Multi-Point
In a multi-drop configuration, this time delay needs to be different for each slave station.
One possibility is to configure each slave station to wait a steadily increasing amount of
time (no duplicate times and all greater than Master_Min time) hence assigning priorities
to the stations. In this way, stations which are important in the system can be given higher
priority and collisions will rarely happen (only if device timing is bad or the system is
poorly configured). However, if the high priority slave stations have nothing to transmit,
then there is a lot of time (and hence bandwidth) wasted.
Another scheme is to configure each slave station to wait a random time between
Master_Min and Max. This Max is a function of the number of slave stations in the
system. In this way, each station can be configured in the same way and the average time
wasted is about (Max - Master_Min) / 2. However, a collision is still possible if two
stations decide to wait for the same amount of time. The smaller the Max value the
greater the chance of this happening.
7.3 FULL-DUPLEX PROCEDURES
When full-duplex procedures are used in a four-wire direct connection circuit, there is no
chance of collision because there exists two independent channels for both the reception
7-2
DNP Users Group
and transmission of messages. In this case, both the master and slave stations can transmit
data at any time when needed. The master still has control of the circuit because there is
only one station to talk to, hence no need to block out other stations.
When full-duplex procedures are used in a four-wire multi-drop system the problem of
collision avoidance increases in complexity. The reason for this lies in the fact that a
physical communication circuit that has two independent channels usually can only detect
traffic in the receive direction. In a two-wire system, any traffic in the receive or transmit
direction can be detected because they are both on the same circuit but in a four-wire
system the transmitted and received messages travel on different circuits.
7.3.1 Point-to-Point
In a point-to-point, full-duplex system both master and slave can transmit at the same
time without collision so there is no need for collision detection/avoidance or access
mechanisms in this case.
7.3.2 Multi-Point
In a full-duplex, multi-drop system, the master station can transmit messages at any time
without collision but may not receive the data link confirmation immediately because
another station (acting as a primary station) may have taken control of the master's
receive circuit before the secondary station or a collision occurred.
The slave station's messages will collide at random because there is no way for the station
to know if another station has control of the master's receive circuit. The solution is to
make use of a control circuit (RTS in the case of RS-232) to signal the slave stations
when another slave station has taken control of the master's receive circuit. This signal
must be an input to the slave stations which indicates a request to take control of the
master's receive circuit.
One simple solution is to allow slave messages to collide. In this way, the master can still
send out high priority messages but there may be a collision which will cause a secondary
station to time-out.
7.3.3 Dial-Up Modem
A dial-up modem uses a four-wire full-duplex circuit that typically requires several
control signals (other than DCD) in order to operate. The dial-up circuit is a point-topoint circuit. However, the meaning of the data carrier signal is quite different than with a
direct circuit. The data carrier (DCD) indicates that the modem is electrically connected
to another modem across the PSN. It does not necessarily mean that data is being
transmitted on the circuit. The CTS (Clear To Send) line indicates to the data link when it
is safe to transmit. The DNP data link will assert the RTS (Request To Send) line before
transmitting each frame and wait for the CTS line to go high before transmitting the data.
The RTS line will then be de-asserted. If the DCD line goes low, the data link will
assume that a connection has been lost and attempt to re-dial if needed.
7-3
DNP V3.00 Data Link Layer (Version 0.02)
7-4
DNP Users Group
LIST OF ABBREVIATIONS AND
ACRONYMS
CRC
cyclic redundancy check
DFC
DIR
DNP
data flow control
direction of physical transmission
Distributed Network Protocol
EPA
enhanced protocol architecture
FCB
FCV
frame control bit
frame count valid
IEC
IED
ISO
International Electrotechnical Commission
intelligent electronic device
International Organization for Standardization
LPDU
LSDU
link protocol data unit
link service data unit
octet
OSI
8-bit data object (byte)
Open System Interconnection
PRM
primary
DNP V3.00 Data Link Layer (Version 0.02)
1
DOCUMENT REVISION HISTORY
Name of Document: DNP V3:00 Transport Functions
Network File Name: P009-0PD.TF
Original Author: Malcolm Smith
Date and Version of Preliminary Release: November 8, 1992 Version 0.00A
Associated Software Release(s): DNP V3.00
Revisions Since Preliminary Release
Date
Version
By Whom
Nov. 08/92
Aug. 20/93
Sep 01/93
May 30/97
0.00A
0.01
0.01
0.01
M. Smith
J. Bhat
AV
S. Tessari
Pages
Affected
All
All
All
All
Reason for Changes
Created
Revised after review
Corrections as per C. Huene
Converted to MSWord 6.0
DNP Users Group
DNP PRODUCT DOCUMENTATION
DNP V3.00
TRANSPORT FUNCTIONS
Document Version: 0.01
Internal File: P009-0PD.TF
Associated Software Release: DNP V3.00
NOTICE OF RIGHTS - DNP USERS GROUP
The contents of this manual are the property of the DNP Users Group.
Revisions or additions to the definition and functionality of the
Distributed Network Protocol cannot be made without express written
agreement from the DNP Users Group or its duly authorized party. In
addition, no part of this document may be altered or revised or added to
in any form or by any means, except as permitted by written agreement
with the DNP Users Group or a Party duly authorized by the DNP Users
Group.
As a Party, duly authorized by the DNP Users Group, Harris
Corporation has made every reasonable attempt to ensure the
completeness and accuracy of this document, however, the information
contained in this manual is subject to change without notice, and does
not represent a commitment on the part of Harris Corporation or the
DNP Users Group. An update program for DNP documents is provided
upon request by Harris Corporation on behalf of the DNP Users Group.
TRADEMARK NOTICES
Brand and product names mentioned in this document are trademarks or
registered trademarks of their respective companies.
TABLE OF CONTENTS
ABOUT THIS DOCUMENT
PURPOSE OF THIS SPECIFICATION
WHO SHOULD USE THIS SPECIFICATION
HELP AND ADDITIONAL DOCUMENTATION
HOW THIS SPECIFICATION IS ORGANIZED
CONVENTIONS USED IN THIS SPECIFICATION
iii
iii
iii
iii
iv
iv
1. OVERVIEW
1-1
2. TRANSPORT FUNCTIONS
2.1 TRANSPORT HEADER
2.2 TRANSPORT HEADER FIELD DEFINITIONS
2.3 FRAME ASSEMBLING
2.4 TRANSMISSION OF MESSAGES
2-1
2-1
2-2
2-3
2-4
3. TRANSPORT SERVICES AND RESPONSIBILITIES
3.1 TRANSPORT FUNCTIONS
3.2 INTERFACE DESCRIPTION
3-1
3-1
3-2
LIST OF ABBREVIATIONS AND ACRONYMS
DNP V3.00 Transport Functions (Version 0.01)
i
TABLE OF FIGURES
FIGURE 2-1
FIGURE 2-2
FIGURE 2-3
FIGURE 2-4
FIGURE 2-5
ii
TRANSPORT LAYER MESSAGE LAYOUT
TH BIT DEFINITIONS
ASSEMBLING OF DATA FROM THREE DATA FRAMES
TRANSMISSION OF A SINGLE FRAME MESSAGE
FRAGMENTING OF A MULTI-FRAME APPLICATION MESSAGE
2-2
2-2
2-3
2-4
2-4
DNP Users Group
ABOUT THIS DOCUMENT
PURPOSE OF THIS SPECIFICATION
This document specifies the Distributed Network Protocol (DNP) V3.00 Transport
Functions, transmission procedures and Transport Protocol Data Unit.
WHO SHOULD USE THIS SPECIFICATION
This specification is intended for communication engineers and programmers interested
in knowing the function and message format of the DNP V3.00 Transport Functions. This
includes programmers implementing and designing DNP V3.00 Transport Functions
software/hardware and quality assurance personnel testing and verifying implementations
of the DNP V3.00 Transport Functions. Application programmers may find this
specification useful in determining how to interface with and make use of the DNP V3.00
Transport Functions. Familiarity with the ISO-OSI 7-layer model, IEC 3-layer EPA and
IEC TC-57 standards is helpful.
HELP AND ADDITIONAL DOCUMENTATION
The following documentation may be helpful.
• IEC 870-5-1 and IEC 870-5-2 standards (or drafts), Technical Committee No. 57 for
data transmission in telecontrol systems
• DNP V3.00 Data Object Library (P009-0BL)
• DNP V3.00 Application Layer (P009-0PD.APP)
• DNP V3.00 Data Link Layer (P009-0PD.DL).
DNP V3.00 Transport Functions (Version 0.01)
iii
HOW THIS SPECIFICATION IS ORGANIZED
1. OVERVIEW
A general overview of the transport functions.
2. TRANSPORT FUNCTIONS
A detailed description of the packet formats and transmission procedures.
3. TRANSPORT SERVICES AND RESPONSIBILITIES
Services provided by an interface to the transport functions.
LIST OF ABBREVIATIONS AND ACRONYMS
CONVENTIONS USED IN THIS SPECIFICATION
In this document, the octet is a term used to refer to an eight bit-data object and is
synonymous with the term byte. The low order bit of an octet is referred to as bit 0 and
the high order bit as bit 7.
Irregular capitalization is used in referencing technical terms which have an associated
verb or noun. For example, data link indications commonly referred to as IND, can also
be described using the word INDication.
iv
DNP Users Group
1. OVERVIEW
This document defines the Distributed Network Protocol (DNP) V3.00 Transport
Functions, Transport Protocol Data Unit (TPDU), as well as transport services and
transmission procedures. Master stations, submaster stations and outstations or intelligent
electronic devices (IEDs) can use these transport functions to pass messages between
primary (originating) stations and secondary (receiving) stations. In this protocol, master
stations, submaster stations and outstations are both originators (primary stations) and
receivers (secondary stations).
The ISO (International Organization for Standardization) OSI (Open System
Interconnection) model supported by this protocol specifies physical, data link and
application layers only. This is termed the Enhanced Protocol Architecture (EPA).
However, to support advanced RTU functions and messages larger than the maximum
frame length as defined by the IEC (International Electrotechnical Committee) document
870-5-1, the DNP V3.00 Data Link is intended to be used with this pseudo-transport layer
which implements message assembly and disassembly.
This pseudo-transport layer is actually a super-data link transport protocol which is
normally found as part of some OSI data links. However, because the IEC data link (DNP
V3.00 Data Link Layer) does not support these functions in the data link, it is necessary
to move them out of the data link in order to maintain compliance.
DNP V3.00 Transport Functions (Version 0.01)
1-1
2. TRANSPORT FUNCTIONS
This section describes the Transport layer functions which act as a pseudo-transport layer
to the DNP data link layer. The pseudo-transport layer function is specific only for those
messages that are larger than one Link Protocol Data Unit (LPDU) between primary and
secondary stations. This pseudo-transport layer acts as the DNP data link user in a
protocol stack consisting of only the DNP Data Link and DNP Application Layer. This
functionality allows the pseudo-transport layer to disassemble one Transport Service Data
Unit (TSDU) into multiple (more than one) Transport Protocol Data Units (TPDUs), or
frames, and assemble multiple (more than one) TPDUs into one TSDU.
This process works as follows:
The pseudo-transport layer takes one TSDU (user data) and breaks it into several
sequenced TPDUs (each with Transport Protocol Control Information (TPCI)). Each
TPDU is sent to the data link layer as Link Service Data Unit (LSDU) for transmission.
It also works in the reverse fashion. The pseudo-transport layer receives multiple TPDUs
from the data link layer and assembles them into one TSDU.
LSDUs are user data fragments which are small enough to fit into the defined FT3 frame
format. When a primary station transmits a message to a secondary station, the transport
functions break the message into LSDUs. These functions add a Transport layer Header
(TH) octet at the beginning of the user data fragments that contain the information for the
secondary station to reconstruct the complete message. All pseudo-transport layer
messages have a TH.
The secondary station checks the TH octet on reception of each LSDU for the correct
sequence and builds a TSDU message for higher layers.
The TH contains information that can identify the first frame, last frame and give every
frame a six-bit sequence number. This information is required to reconstruct a message
and also to guard against higher layers from receiving misdirected or incomplete
messages.
2.1 TRANSPORT HEADER
After the data link receives a complete frame, the data is presented to the transport
functions in a format illustrated below. The TH field is stripped out before the frame is
combined with other frames belonging to the same message. Figure 2-1 shows the
structure of a TPDU.
DNP V3.00 Transport Functions (Version 0.01)
2-1
----------------|
|
|
| TH | USER DATA |
|
|
|
-----------------
Figure 2-1 Transport Layer Message Layout
TH
Transport control octet. One octet in length.
USER DATA 1 to 249 octets in length.
When an application requests the transmission of a long message, the message is broken
into fragments small enough to fit in a single DNP V3.00 Data Link frame. The
maximum size of a fragment is 249 octets of user data. The TH is added to the head of the
fragment and the maximum number of octets to be framed becomes 250 octets.
Maximum data link data count
Data link header data count
Transport header
Application user data
+ 255
-5
-1
= 249
octets
octets
octet
octets
2.2 TRANSPORT HEADER FIELD DEFINITIONS
BIT
----------------------------------------------|
|
|
|
|
|
|
|
|
| FIN | FIR |
|
| SEQUENCE |
|
|
|
|
|
|
|
|
|
|
|
----------------------------------------------7
6
5
4
3
2
1
0
Figure 2-2 TH Bit Definitions
FIN
The final bit indicates that this frame of user data is the last frame of a
sequence which compromises a complete user message.
FIN = 0
More frames follow.
1
Final frame of a sequence.
FIR
The first bit indicates that the frame is the first in a sequence of frame(s)
which comprise a complete message. When a secondary station receives a
frame with the FIR bit set, all previously received unterminated frame
sequences are discarded. The first frame of a sequence may have any
sequence from 0 to 63.
If a frame is received without the FIR bit set and no message sequence is
currently in progress, then the frame is ignored.
If a complete user message is only one frame in length, both the FIR and
FIN bits are set.
FIR = 1
First frame of a sequence.
0
Not the first frame of a sequence.
2-2
DNP Users Group
SEQUENCE The sequence number of the frame is used to check that each frame is
being received in sequence. It guards against missing or duplicated frames.
All user messages start off with a sequence specified in the first frame
which has the FIR bit set (each message may start with any sequence
number between 0 and 63). After sequence number 63 the next sequence
number will be 0.
The sequence number increments for each frame sent to or received from
the same address belonging to the same message and resets at the
beginning of a new message. The sequence number does not have to
increment across message boundaries, i.e. any sequence number is valid
when the FIR bit is set.
2.3 FRAME ASSEMBLING
Figure 2-3 illustrates the assembling of a three-frame message. The first frame of the
message identified by having the FIR bit set in the TH field. The last frame is identified
by having the FIN bit set in the TH field.
USER DATA FRAMES
TRANSPORT DATA BUFFER
-------------| SOURCE = n |
--------------------------| FIR = 1
|
| FIN = 0
|
| SEQUENCE = 3| Note sequence starts with the value in the frame that has the FIR bit = 1
| USER DATA 0 |
-------------- -----------> ------------| USER DATA 0 |
-------------------------| SOURCE = n |
--------------------------| FIR = 0
|
| FIN = 0
|
| SEQUENCE = 4|
| USER DATA 1 |
-------------- -----------> ------------| USER DATA 1 |
------------| USER DATA 0 |
-------------------------| SOURCE = n
|----------------------------------->
-------------SOURCE ADDRESS passed to application
-------------| FIR = 0
|
| FIN = 1
| FIN indicates last frame
| SEQUENCE = 5|
| USER DATA 2 |
-------------- -----------> ------------| USER DATA 2 | FIN indicated this is the last frame of message
------------| USER DATA 1 |
------------| USER DATA 0 | complete message passed to application
------------- ----------->
Figure 2-3 Assembling of Data From Three Data Frames
DNP V3.00 Transport Functions (Version 0.01)
2-3
2.4 TRANSMISSION OF MESSAGES
Figure 2-4 illustrates the transmission of a single frame message using the SEND CONFIRM frame service. Figure 2-5 illustrates the transmission of a multi-frame
message using the SEND - CONFIRM frame service.
FRAMES SENT FROM DATA LINK
CONFIRM FRAMES RECEIVED
COMPLETE MESSAGE FROM APPLICATION
|
--------------DESTINATION | parameter from application
---------------
|
|
|
--------------USER DATA
|
|
30 octets
|
---------------
-------------| DESTINATION | parameter to data link
--------------------------| FIR = 1
|
| FIN = 1
| 1 TH octet
| SEQUENCE = 1 |
| USER DATA 0 | send 30 user octets plus 1 TH = 31 octets
SEND
<----- -------------CONFIRM ------->
--------------------> SUCCESS to application layer
Figure 2-4 Transmission of a Single Frame Message
|
-------------DESTINATION | parameter from application
--------------
|
|
|
-------------USER DATA
|
|
598 octets |
--------------
-------------| DESTINATION | parameter to data link
--------------------------| FIR = 1
|
| FIN = 0
| 1 TH octet
| SEQUENCE = 2 |
| USER DATA 0 | send 249 octets (1 to 249 is the valid range for this count)
SEND
<------- -------------CONFIRM --------> -------------| DESTINATION | parameter to data link
--------------------------| FIR = 0
|
| FIN = 0
|
| SEQUENCE = 3 |
| USER DATA 1 | send 249 octets
SEND
<------- -------------CONFIRM --------> -------------| DESTINATION | parameter to data link
--------------------------| FIR = 0
|
| FIN = 1
|
| SEQUENCE = 4 |
| USER DATA 2 | send last 100 octets (249 + 249 + 100 = 598)
SEND
<------- -------------CONFIRM -------->
--------------------> SUCCESS to application layer
Figure 2-5 Fragmenting of a Multi-Frame Application Message
2-4
DNP Users Group
3. TRANSPORT SERVICES AND
RESPONSIBILITIES
3.1 TRANSPORT FUNCTIONS
This section describes the services offered by the pseudo-transport layer and its function.
The communication requirements of the network layer and the application layer are
satisfied by the pseudo-transport layer service primitives.
The pseudo-transport layer is responsible for performing the following functions:
• Packing user data into multiple frames (more than one) of the defined DNP V3.00
Data Link frame format and using the services of the DNP V3.00 Data Link for
transmitting the data
• Unpacking multiple frames that are received from the data link into user data
• Controlling all aspects of the data link excluding data link configuration.
The pseudo-transport layer is responsible for providing the following services:
• Exchange of SDUs between peer DNP V3.00 pseudo-transport layers
• Error notification to transport user
• Sequencing of SDUs
• Prioritized SDU delivery
• Quality SDU delivery.
SDUs will only be exchanged between peer DNP V3.00 pseudo-transport layers.
Error notification is given to the transport user when a response to a request has not been
received.
Priority delivery can be set to EXPEDITED or NORMAL to indicate a high or low
priority request.
Quality delivery can be set to SEND-NO-REPLY or SEND-CONFIRM to indicate
whether or not message acknowledgment is required.
DNP V3.00 Transport Functions (Version 0.01)
3-1
3.2 INTERFACE DESCRIPTION
The pseudo-transport layer service primitives are illustrated in pseudo code to illustrate
the requirements and behavior in a real implementation and are not intended as an exact
interface definition.
Transport request (REQ) services can be used at any time after the transport functions
have been initialized and configured by the system.
confirm =
request_transport_service(
SERVICE,
TIME_SERVICE,
destination,
source,
send_data_buffer,
send_count,
retry_flag,
time_of_transmission)
Input:
SERVICE
TIME_SERVICE
source
destination
send_data_buffer
send_count
retry_flag
time_of_transmission
Service to perform.
Guaranteed time service to perform.
Source address to use in sent message.
Destination address to use in sent message.
Data to send in message.
Number of octets in message.
Instructs data link layer to retry unacknowledged frames or not.
Time that first bit of first octet of message is to be sent.
Output:
time_of_transmission Time that first bit of first octet of message was sent
confirm =
0
1
2
3
4
3-2
Requested service is successful.
Requested service has failed.
Requested SEND data service is terminated by the current primary
station. (reception of a NACK frame from the secondary station).
Service code is not implemented.
Requested service cannot proceed at this time because the data link
is busy either with a previous requested transaction, current
unrequested transaction or waiting for physical layer availability.
DNP Users Group
service =
0
1
2
3
4
time_service =0
1
Send a message specified in parameters using SEND-CONFIRM
frames. Fails if the data link is busy.
Send a message specified in parameters using SEND-NO- REPLY
frames. Fails if the data link is busy.
Expedited send a message specified in parameters using SENDCONFIRM frames. May necessitate canceling the current
secondary transaction if a half-duplex system is used.(i.e. forces the
data link to send a NACK frame instead of a CONFIRM frame in
the next secondary transaction). This action only takes place if the
primary station is using SEND-CONFIRM frames.
Expedited send a message specified in parameters using SENDNO-REPLY expected frames. In a half-duplex system, this may
mean canceling the current secondary transaction. (as above).
Return link status. Return successful if the data link is not busy.
Send message at time specified in time_of_transmission. This
service should have the highest priority.
Send message at any time with priority specified.
Data link indications (IND) can be requested at any time by the service user but should be
checked as often as possible in order to obtain received data.
indications = request_data_link_indications(
source_address,
destination_address,
received_data_buffer,
received_data_count,
time_of_reception)
Output:
source_address
destination_address
received_data_buffer
received_data_count
time_of_reception
Source address of received message.
Destination address of received address.
Received message.
Number of octets in message.
Time at which first bit of first octet of message was received.
DNP V3.00 Transport Functions (Version 0.01)
3-3
Indications = 0
1
2
3-4
No indications to report.
Data link has received a valid message that has been placed in
received_data_buffer and the number of octets received has been
placed in received_data_count. The source address of the received
message has been placed in source_address. If the data link is
configured as a master station then the time that the first bit of the
first octet of the message was received has been placed in
time_of_reception. If the data link is configured as an outstation
then the time_of_reception will still be returned but the service
user has to be aware of the possibility of inaccurate times received
before the outstation has been time-synchronized.
Pseudo-transport layer has detected a transaction failure.
DNP Users Group
LIST OF ABBREVIATIONS AND
ACRONYMS
CRC
cyclic redundancy check
DNP
Distributed Network Protocol
EPA
enhanced protocol architecture
IEC
ISO
International Electrotechnical Commission
International Organization for Standardization
octet
OSI
8-bit data object (byte)
Open System Interconnection
RTU
remote terminal unit
DNP V3.00 Transport Functions (Version 0.01)
1
DOCUMENT REVISION HISTORY
Name of Document: DNP V3.00 Application Layer Protocol Description
Network File Name: P009-0PD.APP
Original Author: Malcolm Smith/Jim McFadyen
Date and Version of Preliminary Release: August 7, 1991 Version 0.00
Associated Software Release(s): DNP V3.00
Revisions Since Preliminary Release
Date
Version
By Whom:
Sept. 30/91 0.00A
NFM
Pages
Affected:
All
Nov. 11/91
Nov. 18/91
Jan. 13/92
Apr. 30/92
Jul. 24/92
0.00B
0.00C
0.01A
0.01B
0.01C
J. McFadyen
J. McFadyen
J. McFadyen
NFM
MCH
Section 3
All
3-11
Sep. 8/92
0.02A
M. Smith
ALL
Oct. 22/92
0.02B
M.Smith
Timesync
Oct. 27/92
0.02C
M.Smith
Section 3
Nov.8/92
0.02D
MS
Nov.25/92
July 7/93
Jul.21/93
Aug.20/93
Aug.30/93
Sept.01/93
0.03
0.03
0.03
0.03
0.03
0.03
LA
P. Morton
J. Bhat
J. Bhat
J. Bhat
AV
Sections
3, 4
All
All
All
All
All
All
Reason for Changes:
Document renamed and relocated from
O:\Document\Other\DOC0362.wp to
P009-0FS.APP Reformatted to WI
standards
Corrections
Minor corrections
Addition of Application Control fields
Minor fixes per J. McFadyen.
Reversed MSB and LSB in Figure 3-7
as per J. McFadyen.
Re-design of qualifier, clarification of
function code usage, added support of
multi-fragment objects, changed
terminology to match IEC definitions.
Removed all references to TIMESYNCHRONIZATION in the
Application Layer as this is a Data Link
function.
Re-defined Application Control (AC)
octet to handle sequencing of
fragments and added diagrams to
illustrate this. Changed name of
document.
Re-added TIME-SYNC and made
some technical corrections.
Reformatted to WI standards.
Reformatted, added chapters.
Removed Section 9, Reformatted.
Re-edited and reformatted.
Re-edited and reformatted.
Format check, glossary, footers.
Date
Version
By Whom:
May 28/97
0.03
S. Tessari
Pages
Affected:
All
Reason for Changes:
Converted to MS Word 6.0
DNP Users Group
DNP PRODUCT DOCUMENTATION
DNP V3.00
APPLICATION LAYER
Document Version: 0.03
Internal File: P009-0PD.APP
Associated Software Release: DNP V3.00
NOTICE OF RIGHTS - DNP USERS GROUP
The contents of this manual are the property of the DNP Users Group.
Revisions or additions to the definition and functionality of the
Distributed Network Protocol cannot be made without express written
agreement from the DNP Users Group or its duly authorized party. In
addition, no part of this document may be altered or revised or added to
in any form or by any means, except as permitted by written agreement
with the DNP Users Group or a Party duly authorized by the DNP Users
Group.
As a Party, duly authorized by the DNP Users Group, Harris
Corporation has made every reasonable attempt to ensure the
completeness and accuracy of this document, however, the information
contained in this manual is subject to change without notice, and does
not represent a commitment on the part of Harris Corporation or the
DNP Users Group. An update program for DNP documents is provided
upon request by Harris Corporation on behalf of the DNP Users Group.
TRADEMARK NOTICES
Brand and product names mentioned in this document are trademarks or
registered trademarks of their respective companies.
TABLE OF CONTENTS
ABOUT THIS DOCUMENT
PURPOSE OF THIS SPECIFICATION
WHO SHOULD USE THIS SPECIFICATION
HELP AND ADDITIONAL DOCUMENTATION
HOW THIS SPECIFICATION IS ORGANIZED
CONVENTIONS USED IN THIS SPECIFICATION
ix
ix
ix
ix
x
x
1. OVERVIEW
1.1 DESCRIPTION AND IEC RELATIONSHIP
1-1
1-2
2. MESSAGE FORMATS
2.1 APPLICATION REQUEST FORMAT
2.2 APPLICATION RESPONSE FORMAT
2-1
2-2
2-2
3. DEFINITION OF DNP MESSAGE FIELDS
3.1 APPLICATION HEADERS
3.2 COMMUNICATION FLOW CONTROL
3.3 MASTER REQUEST & UNSOLICITED RESPONSE COLLISIONS
3.4 ERROR RECOVERY
3.5 FUNCTION CODES
3.6 INTERNAL INDICATIONS
3.7 OBJECT HEADER
3-1
3-1
3-3
3-8
3-11
3-12
3-14
3-16
4. DETAILED FUNCTION CODE DESCRIPTIONS
4-1
4.1 CONFIRM (FUNCTION CODE 0)
4-1
4.2 READ (FUNCTION CODE 1)
4-2
4.3 WRITE (FUNCTION CODE 2)
4-14
4.4 SELECT (FUNCTION CODE 3)
4-16
4.5 OPERATE (FUNCTION CODE 4)
4-18
4.6 DIRECT OPERATE (FUNCTION CODE 5)
4-19
4.7 DIRECT OPERATE - NO ACKNOWLEDGEMENT (FUNCTION CODE 6) 4-19
4.8 IMMEDIATE FREEZE (FUNCTION CODE 7)
4-20
4.9 IMMEDIATE FREEZE - NO ACKNOWLEDGEMENT (FUNCTION CODE 8)4-20
4.10 FREEZE AND CLEAR (FUNCTION CODE 9)
4-20
4.11 FREEZE AND CLEAR - NO ACKNOWLEDGEMENT (FUNCTION CODE 10)4-21
DNP V3.00 Application Layer (Version 0.03)
v
4.12 FREEZE WITH TIME (FUNCTION CODE 11)
4-21
4.13 FREEZE WITH TIME - NO ACKNOWLEDGEMENT (FUNCTION CODE 12)4-22
4.14 COLD RESTART (FUNCTION CODE 13)
4-22
4.15 WARM RESTART (FUNCTION CODE 14)
4-23
4.16 INITIALIZE DATA (FUNCTION CODE 15)
4-23
4.17 INITIALIZE APPLICATION (FUNCTION CODE 16)
4-24
4.18 START APPLICATION (FUNCTION CODE 17)
4-25
4.19 STOP APPLICATION (FUNCTION CODE 18)
4-25
4.20 SAVE CONFIGURATION (FUNCTION CODE 19)
4-26
4.21 ENABLE SPONTANEOUS MESSAGES (FUNCTION CODE 20)
4-26
4.22 DISABLE SPONTANEOUS MESSAGES (FUNCTION CODE 21)
4-27
4.23 ASSIGN CLASSES (FUNCTION CODE 22)
4-27
4.24 DELAY MEASUREMENT (FUNCTION CODE 23)
4-28
5. CLASSES
5-1
6. TIME SYNCHRONIZATION
6-1
7. BINARY INPUT WITH TIME EVENTS
7-1
8. FILE TRANSFER
8.1 FILE IDENTIFIER OBJECTS PERFORMING WRITE FUNCTIONS
8.2 FILE IDENTIFIER OBJECT PERFORMING READ FUNCTIONS
8-1
8-1
8-5
LIST OF ABBREVIATIONS AND ACRONYMS
vi
DNP Users Group
TABLE OF FIGURES
FIGURE 1-1 CONTEXT OF EPA
1-2
FIGURE 2-1 MESSAGE SEQUENCE
2-1
FIGURE 2-2 APPLICATION REQUEST FORMAT
2-2
FIGURE 2-3 APPLICATION RESPONSE FORMAT
2-3
FIGURE 3-1 REQUEST HEADER
3-1
FIGURE 3-2 RESPONSE HEADER
3-1
FIGURE 3-3 APPLICATION CONTROL FIELD
3-2
FIGURE 3-4 TYPICAL MESSAGE TRANSACTION FLOW
3-4
FIGURE 3-5 MULTI-FRAGMENT RESPONSE & RTU CONFIRMATION
TIMEOUT
3-5
FIGURE 3-6 MESSAGE TRANSACTIONS WITH RESPONSE TIMEOUTS
3-6
FIGURE 3-7 MESSAGE FLOW WHEN RESPONSE DELAYED ON A
NETWORK
3-7
FIGURE 3-8 RESENDING UNSOLICITED RESPONSES DUE TO NETWORK
DELAYS
3-7
FIGURE 3-9 SIMULTANEOUS TRANSMISSIONS, IMMEDIATE_PROCESS
MODE
3-9
FIGURE 3-10 SIMULTANEOUS TRANSMISSIONS, IMMEDIATE_PROCESS
MODE
3-10
FIGURE 3-11 SIMULTANEOUS TRANSMISSIONS, PROCESS_AFTER_CONFIRM
MODE
3-11
FIGURE 3-12 OBJECT HEADER
3-16
FIGURE 3-13 OBJECT FIELD
3-17
FIGURE 3-14 QUALIFIER FIELD
3-18
FIGURE 3-15 MESSAGES WITHOUT DATA OBJECTS
3-23
FIGURE 3-16 MESSAGES WITH DATA OBJECTS
3-26
FIGURE 4-1 CONFIRMATION MESSAGE
4-1
FIGURE 4-2 SINGLE OBJECT REQUEST
4-3
FIGURE 4-3 MULTIPLE OBJECTS OR RANGES
4-3
FIGURE 4-4 SINGLE OBJECT RANGE WRITE
4-15
FIGURE 4-5 MULTIPLE OBJECT OR MULTIPLE RANGES
4-15
FIGURE 4-6 MASTER SELECTION OF TWO CONTROL OR ANALOG
OUTPUTS
4-17
FIGURE 4-7 OUTSTATION RESPONSE
4-17
FIGURE 4-8 MASTER SELECTION OF A PATTERN OUTPUT
4-17
FIGURE 4-9 OUTSTATION RESPONSE TO THE PATTERN SELECT
MESSAGE
4-18
DNP V3.00 Application Layer (Version 0.03)
vii
FIGURE 4-10 MASTER SELECTION OF TWO OUTPUTS OR SETPOINTS
4-18
FIGURE 4-11 OUTSTATION RESPONSE
4-18
FIGURE 4-12 MASTER SELECTION OF TWO OUTPUTS OR SETPOINTS
4-19
FIGURE 4-13 OUTSTATION RESPONSE
4-19
FIGURE 4-14 MASTER SELECTION OF TWO OUTPUTS OR SETPOINTS
4-19
FIGURE 4-15 MASTER IMMEDIATE FREEZE CONTROL MESSAGE
4-20
FIGURE 4-16 OUTSTATION RESPONSE TO IMMEDIATE FREEZE
4-20
FIGURE 4-17 MASTER IMMEDIATE FREEZE NO-ACK CONTROL MESSAGE 4-20
FIGURE 4-18 MASTER FREEZE AND CLEAR CONTROL MESSAGE
4-21
FIGURE 4-19 OUTSTATION RESPONSE TO FREEZE AND CLEAR REQUEST 4-21
FIGURE 4-20 MASTER FREEZE AND CLEAR NO-ACK CONTROL MESSAGE 4-21
FIGURE 4-21 MASTER FREEZE WITH TIME MESSAGE
4-22
FIGURE 4-22 OUTSTATION RESPONSE TO FREEZE WITH TIME
4-22
FIGURE 4-23 MASTER FREEZE WITH TIME NO-ACK MESSAGE
4-22
FIGURE 4-24 MASTER COLD RESTART CONTROL MESSAGE
4-23
FIGURE 4-25 OUTSTATION RESPONSE TO COLD RESTART REQUEST
4-23
FIGURE 4-26 MASTER WARM RESTART CONTROL MESSAGE
4-23
FIGURE 4-27 OUTSTATION RESPONSE TO WARM RESTART REQUEST
4-23
FIGURE 4-28 MASTER INITIALIZE DATA CONTROL MESSAGE
4-24
FIGURE 4-29 OUTSTATION RESPONSE TO INITIALIZE DATA REQUEST
4-24
FIGURE 4-30 MASTER INITIALIZE APPLICATION CONTROL MESSAGE
4-24
FIGURE 4-31 OUTSTATION RESPONSE AFTER INITIALIZING
APPLICATION(S)
4-24
FIGURE 4-32 MASTER START APPLICATION CONTROL MESSAGE
4-25
FIGURE 4-33 OUTSTATION RESPONSE AFTER STARTING
APPLICATION(S)
4-25
FIGURE 4-34 MASTER STOP APPLICATION CONTROL MESSAGE
4-25
FIGURE 4-35 OUTSTATION RESPONSE AFTER STOPPING
APPLICATION(S)
4-26
FIGURE 4-36 MASTER SAVE CONFIGURATION CONTROL MESSAGE
4-26
FIGURE 4-37 OUTSTATION RESPONSE AFTER SAVING
CONFIGURATION(S)
4-26
FIGURE 4-38 MASTER REQUEST TO ENABLE SPONTANEOUS MESSAGES 4-27
FIGURE 4-39 OUTSTATION RESPONSE
4-27
FIGURE 4-40 MASTER REQUEST TO DISABLE SPONTANEOUS MESSAGES 4-27
FIGURE 4-41 OUTSTATION RESPONSE TO DISABLE SPONTANEOUS
MESSAGE
4-27
FIGURE 4-42 MASTER REQUEST TO ASSIGN CLASSES TO DATA
4-28
FIGURE 4-43 OUTSTATION RESPONSE TO ASSIGN CLASSES
4-28
FIGURE 4-44 MASTER REQUEST TO INITIATE DELAY MEASUREMENT
4-28
FIGURE 4-45 OUTSTATION REPONSE TO DELAY MEASUREMENT
REQUEST
4-29
FIGURE 8-1 PASSING A FILE IDENTIFIER OBJECT VIA DATA
CONCENTRATORS
8-4
viii
DNP Users Group
ABOUT THIS DOCUMENT
PURPOSE OF THIS SPECIFICATION
This document specifies the Distributed Network Protocol (DNP) application layer
services and message format. This document specifies the Application Protocol Data Unit
(APDU), application data flow control and any specific information pertaining to DNP
application layer services.
WHO SHOULD USE THIS SPECIFICATION
This specification is for people who need to know the structure and meaning of the fields
that make up the application layer message.
This includes programmers implementing and designing an application and Quality
Assurance personnel testing and verifying implementations of the application layer.
HELP AND ADDITIONAL DOCUMENTATION
The following documentation may be helpful.
• DNP V3.00 Data Object Library (P009-0BL).
DNP V3.00 Application Layer (Version 0.03)
ix
HOW THIS SPECIFICATION IS ORGANIZED
1. OVERVIEW
A general overview of the application layer.
2. MESSAGE FORMATS
A definition of the request and response formats.
3. DEFINITION OF THE DNP MESSAGE FIELDS
A detailed explanation of the message field.
4. DETAILED FUNCTION CODE DESCRIPTION
A description of the function codes.
5. CLASSES
A description of the classes.
6. TIME SYNCHRONIZATION
A description of time synchronizing.
7. BINARY INPUT WITH TIME EVENTS
A description of binary input with time events.
8. FILE TRANSFER
A description of file transfer.
LIST OF ABBREVIATIONS AND ACRONYMS
CONVENTIONS USED IN THIS SPECIFICATION
The term octet used in this document refers to an eight-bit data object and is synonymous
with the term byte. The low order bit of an octet is numbered as bit zero (0) and the high
order is bit seven (7). Data octets illustrated in this document are received and transmitted
from left to right.
x
DNP Users Group
1. OVERVIEW
This document defines the Harris Distributed Network Protocol (DNP) application layer
APDU format and services.
The ISO OSI (International Standards Organization Open System Interconnection) model
specifies seven layers. The International Electrotechnical Commission (IEC) specifies a
simplified model consisting of the physical, data link and application layers only. This is
termed the Enhanced Performance Architecture (EPA). This document defines the third
layer of this EPA or the Application Layer. The data link layer is defined in:
Distributed Network Protocol Version 3.00: Data Link Layer (P009-0PD.DL).
Harris Canada Inc. has developed the DNP for application in both SCADA and
distributed automation (DA) systems. Primary focus has been on the current and future
needs of these areas. The DNP is suitable for use in highly secure, moderate speed and
moderate throughput applications. The protocol is highly flexible and open-ended
without any target hardware specific constructs.
Figure 1-1 on the following page shows the EPA structure and how it fits into the entire
communication system. As shown, the User Layer interfaces to the Application Layer in
one place only implying that the user has no need to know of the other elements of the
communication system except the Application Layer interface. The User Layer makes
use of the Application Layer to send/receive complete SCADA/DA messages to/from a
master station or outstation.
DNP V3.00 Application Layer (Version 0.03)
1-1
User Layer
Application Layer
Data Link Layer
Physical Layer
Communication Medium
Figure 1-1 Context of EPA
1.1 DESCRIPTION AND IEC RELATIONSHIP
The DNP Application Layer APDU is based in principle on the IEC 870-5-3 and 870-5-4
draft documents as prepared by TC-57 WG 03. Structurally, the Application Layer PDU
(Protocol data Unit) fits the IEC description of an APDU. The user sends Application
User Data to the Application Layer where it is converted to ASDU (Application Service
Data Unit). In DNP, the Application User Data is converted into multiple ASDUs. Each
ASDU is then prefixed by APCI (Application Protocol Control Information) which is
then packaged as an APDU. In DNP, each APDU that is part of the larger multi-APDU is
referred to as a fragment and there is a restriction that each fragment contains complete
data objects only and that the function code portion of the APCI (Application Protocol
Control Information) is identical in each fragment of the same message or multi-APDU.
That is, there will be no fragmentation of information objects between APDUs and the
same operation must be requested of each object in the message. This is to ensure that
each fragment on its own can be processed and also implies that each ASDU contains
only complete data objects. In reverse, the Application Layer receives multiple APDU
(one at a time) where it removes the APCI to obtain the ASDU and assembles the ASDUs
into Application User Data.
1-2
DNP Users Group
2. MESSAGE FORMATS
This section defines the formats of the application layer messages (APDU). The terms
APDU and fragment are interchangeable. In this specification the master station is
defined as the station sending a request message and the Outstation is the slave device,
Remote Terminal Unit (RTU) or Intelligent End Device (IED) to which the requested
messages is destined. In DNP, only designated master stations can send Application
Layer request messages and only Outstations can send Application Layer Response
messages.
Figure 2-1 below shows the sequence of Application Layer messages between one master
and one Outstation.
Master
Outstation
Send Request
-------------------->
<--------------------
Accept response
<-----------------
Optional confirmation
Accept request and process
Optional confirmation
Send Response
--------------------------------->
Important change detected
Accept response
<-----------------
Optional confirmation
Send Unsolicited Response
--------------------------------->
Figure 2-1 Message Sequence
As shown above, the master station sends an Application Layer Request to the outstation
which returns an Application Layer Response. The outstation can decide to
spontaneously transmit data using an Application Layer Unsolicited Response message.
For a master, a request/response transaction with a particular outstation must be
completed before another requests can be sent to that outstation. A master station may
accept unsolicited responses while the request transaction is in progress. For an
outstation, a request/response transaction must be completed before any other requests are
accepted or unsolicited responses are sent. Unsolicited responses can be sent before or
after the request/response transaction but not during. If an outstation is presently in the
middle of an unsolicited transaction (i.e. waiting for a confirmation), it may conditionally
accept one request command from the master. (For detailed information, see Section 3.3 Master Request and Unsolicited Response Collisions).
In addition, each response or request can consist of 1 or more individual fragments.
Each fragment however should be digestible (parsable) and therefore executable (because
DNP V3.00 Application Layer (Version 0.03)
2-1
the function code is part of every fragment). It is advised that devices with limited
message storage capabilities should only be sent single fragment message requests when
the expected response (from all fragments sent) is larger than one fragment. This is to
ensure that devices can process a request and build and more importantly send a response
before the next request is received. Otherwise, multi-fragment messages may require
multi-fragment responses which may require more message storage than the device has
available.
2.1 APPLICATION REQUEST FORMAT
The application request message format (APDU) is illustrated in Figure 2-2. The APDU
is made up of an APCI block which contains message control information and an ASDU
which contains information to be processed by the receiving station. The APCI is often
called a request header in an application request message. In DNP, the ASDU is optional
and is used when the message meaning is not conveyed completely in the request header.
The request header contains information on how to assemble a multi-fragment message
and on the purpose of the message. The request header is present in all application layer
request APDUs. If the request header implies all the needed information required to carry
out the request, the ASDU is not present.
Each ASDU consists of one or more Data Unit Identifiers (DUI) or object headers and
optional associated Information Objects (IO) or data fields. The object header can specify
0 or more en that returned by the receiving station or that follow the header in the
message.
•
DUI
• IO .. IO •
DUI
• IO •
•••••••••••••••••••••••••••••••••••••••••• ....••••••••••••••••••••••••
• Request Header • Object Header • data •
• Object Header • data •
•
•
•
•
•
•
•
••••••••••••••••••••••••••••••••••••••••••.....••••••••••••••••••••••••
•
APCI
•
ASDU
•
Figure 2-2 Application Request Format
Request Header
Object Header
Data
The request header identifies the purpose of the message and
consists of APCI (Application Protocol Control Information).
This header identifies the data objects that follow.
Data object(s) of the type specified in the object header.
2.2 APPLICATION RESPONSE FORMAT
The response from an Outstation to an application layer request APDU or the unsolicited
response from an outstation have the format illustrated in Figure 2-3. The format is
identical in form to the request. The APCI is often called a response header in an
application response message. The response header contains the same information as the
request header plus an additional field containing internal indications of the outstation.
The response header is always part of the application response. The response ASDU has
2-2
DNP Users Group
the same format of the request message with one notable exception (explained in Section
3).
•
DUI
• IO .. IO •
DUI
• IO •
•••••••••••••••••••••••••••••••••••••••••• ....••••••••••••••••••••••••
• Response Header• Object Header • data •
• Object Header • data •
•
•
•
•
•
•
•
••••••••••••••••••••••••••••••••••••••••••.... ••••••••••••••••••••••••
•
APCI
•
ASDU
•
Figure 2-3 Application Response Format
Response Header
Object Header
Data
The response header identifies the purpose of the message and
consists of APCI (Application Protocol Control Information).
This header identifies the data objects that follow.
Data object(s) of the type specified in the object header.
DNP V3.00 Application Layer (Version 0.03)
2-3
2-4
DNP Users Group
3. DEFINITION OF DNP MESSAGE
FIELDS
This section describes the request and response headers (APCIs) which control the
sequence and flow of application messages between a master station and an Outstation,
and the ASDU which include DUI or data object headers. The headers are used to
assemble multi-fragment (multi-APDU) messages into Application User Data. The
object headers are used to identify uniquely the information object(s) that optionally
follow the header.
3.1 APPLICATION HEADERS
3.1.1 Request Header
The request header or APCI has two fields. Each field is one octet in length and is
illustrated below.
•••••••••••••••••••••••••••••••••••••••
• Application Control • Function Code •
•
AC
•
FC
•
•••••••••••••••••••••••••••••••••••••••
Figure 3-1 Request Header
3.1.2 Response Header
The response header has three fields as illustrated below.
••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••
• Application Control • Function Code • Internal Indications •
•
AC
•
FC
•
IIN
•
•
•
•
•
••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••
Figure 3-2 Response Header
3.1.3 Application Control
The application control field has a size of one octet. It provides information needed to
construct multi-fragment application messages.
DNP V3.00 Application Layer (Version 0.03)
3-1
Application messages may be packaged into fragments, with each fragment small enough
to fit into the application's message buffer. The recommended size of the fragment buffer
is 2048 bytes in order to maintain compatibility with current DNP devices. Each fragment
has an application header and appropriate object headers so that each fragment can be
processed as individual messages which can then be discarded making room for the next
fragment.
7
6
5
4
3
2
1
0 bit
••••••••••••••••••••••••••••••••••••••••••••••••••
• FIR • FIN • CON
•
SEQUENCE
•
•
•
•
•
•
••••••••••••••••••••••••••••••••••••••••••••••••••
Figure 3-3 Application Control Field
FIR
If set to one (1), this bit indicates the message fragment is the first fragment of a
complete application message.
FIN
If set to one (1), this bit indicates the message fragment is the final fragment of a
complete application message.
CON If set to one (1) in a received message, indicates the sending application is
expecting a confirmation from the receiving application of the reception of the
fragment. An application function code zero (0) is used in the confirmation
message.
SEQUENCE Indicates the fragment number. Fragment numbers 0 to 15 are reserved for
master station requests and all Outstation responses (NOT Unsolicited
Responses). Fragment numbers 16 to 31 are reserved for unsolicited
responses from Outstations. For unsolicited responses, each consecutive
fragment from an Outstation must have an increasing sequence number
(the number overflows from 31 to 16). For requests to an Outstation and
the Outstation responses (not unsolicited responses), each consecutive
fragment received from or transmitted to the same Outstation must have an
increasing sequence number (the number overflows from 15 to 0).
NOTE:
An Unsolicited Response is a message generated by an Outstation,
usually containing event data, which is sent automatically to the master.
The master does not need to poll the Outstation for this data.
NOTE:
It is recommended that any changed data that is reported from an
Outstation be sent with a confirmation requested in the response.
3-2
DNP Users Group
3.2 COMMUNICATION FLOW CONTROL
The flow of requests and responses between the master and the Outstation is controlled
by fields in the response and request headers as well as application timers and parameters.
The fields, timers and parameters controlling message flow are:
1)
2)
3)
4)
5)
CON bit field. Setting/clearing this bit enables/disables message CONFIRMation
responses. A CONFIRMation response is an application acknowledgments of the
previous request or response message.
FIR and FIN bit fields.
Sequence Number field. This number is used to assemble multi-fragment
messages and identify which responses match particular requests.
Master station and Outstation application response time-outs. These specify how
long an application must wait for a response or CONFIRMation response before
re-transmitting or aborting the transaction. The application may or may not
support re-transmission of transactions at the application layer.
Master station and Outstation application retry count. Applications may or may
not support application level retries. Retry counters specify how many times a
request is repeated if a response fails, or how often responses are re-transmitted if
a CONFIRMation response is not received.
An Outstation must completely process a request and respond to it before beginning to
process a second request. It cannot simultaneously process multiple requests.
The Sequence Number for all requests from the master station to the Outstation is
in the range 0 to 15 inclusive. The sequence number for all Unsolicited Responses
from the Outstation is in the range 16 to 31 inclusive.
The following rules dictate how sequence numbers work:
• The sequence number rolls over from 15 to 0 or from 31 to 16. Each successive
request fragment from the DNP master station has an incremented sequence number.
The exception is for retries on requests. For single fragment request retries, the
sequence number is NOT incremented. For multi fragment request retries, the
sequence number of the first fragment of the request retry equals the sequence number
of the last fragment of the request which has just failed.
• A single fragment response to a single fragment request has the same sequence number
as the request.
• The CONFIRMation response to a request or response has the same sequence number
as the request or response.
• The first fragment of a multi-fragment response to a single fragment request has the
same sequence number as the request. For successive fragment of the multi-fragment
response, the sequence number is incremented.
• The first fragment of a multi-fragment response to a multi-fragment request has the
same sequence number as the last fragment of the multi-fragment request.
DNP V3.00 Application Layer (Version 0.03)
3-3
The use of this sequence number scheme ensures the Outstation and master station can
cope with all occurrences of messages being lost or delayed on a communication network.
The following rules are obeyed by both the Outstation and master station:
• If the system uses application level retries, when a response is not received before
time-out, the request will be re-transmitted with the same sequence number.
• If two messages are received with the same sequence number, it usually means that the
response to the message was not received by the other station. In this case, retransmit
the response (re-processing the message is unnecessary).
• If two CONFIRMation responses are received with the same sequence number, ignore
the second response.
The following figures illustrate some cases of message transactions and how the
Sequence Numbers prevent problems. In the examples, SEQ is the Sequence Number
and CON is the Confirmation Requested bit in the message. Time progresses from left to
right in the diagrams. The vertical arrows represent the flow of messages between the
Outstation and the master station.
Case One illustrates typical message transactions. The master sends a request, the
Outstation responds and the master CONFIRMs the response. Later on, the Outstation
sends an Unsolicited Response to the master station. When the Outstation transmits the
response, it starts a CONFIRMation response timer. If this timer had expired before the
CONFIRMation was received, the Outstation would have re-transmitted the response.
Case Two shows a similar situation to Case One except the master request requires a
CONFIRMation response as well as a normal response.
CASE 1
Time
••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••→
Master
• Request.
•
•
• Response
• CONFIRM
• CONFIRM
• expected.
• (SEQ=7)
• (SEQ=24)
• (CON=0)
•
•
• (SEQ=7)
•
•
▼
▼
▼
-------------------------------------------------------------------Outstation
▲
▲
• Response
• Unsol.
• to master
• Response
• (CON=1)
• (CON=1)
• (SEQ=7)
• (SEQ=24)
•
•
CASE 2
Time
••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••→
Master
• Request.
•
• Response
• CONFIRM
• expected.
• (SEQ=2)
• (CON=0)
•
• (SEQ=2)
•
▼
▼
-------------------------------------------------------------------Outstation
▲
▲
• CONFIRM
• Response
• (SEQ=2)
• to master
•
• request
•
• (CON=1)
•
• (SEQ=2)
Figure 3-4 Typical Message Transaction Flow
3-4
DNP Users Group
NOTE:
In Figure 3-4 and some of the following figures, the CON bit is set in the
Outstation responses. The CON bit may be clear in some transaction (e.g.
when the response does not contain event data). In this case, data loss due
to communication loss is often not critical. The Outstation assumes that
the response was successful.
Case Three illustrates a multi-fragment response from the Outstation. The sequence
number in successive fragments is incremented. Note that the next request from the
master station used sequence number equals 4.
In Case Four, the response from the Outstation is not received by the master station. The
Outstation waits for a CONFIRMation, and when its CONFIRMation time-out expires it
re-transmits the response.
CASE 3
Time
••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••→
Master
• Request.
•
•
• Request.
• Response
• CONFIRM
• CONFIRM
• (SEQ=4)
• expected.
• (SEQ=2)
• (SEQ=24)
•
• (CON=0)
•
•
•
• (SEQ=2)
•
•
•
▼
▼
▼
▼
-------------------------------------------------------------------Outstation
▲
▲
• Response
• Response
• Frag. 1
• Frag. 2
• (CON=1)
• (CON=1)
• (SEQ=2)
• (SEQ=3)
•
•
CASE 4
Time
••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••→
Master
• Request.
•
• Response
Response
• CONFIRM
• expected.
not
• (SEQ=3)
• (CON=0)
received.
•
• (SEQ=3)
•
▼
▼
-------------------------------------------------------------------Outstation
▲
▲
• Response
CONFIRM not
• Response
• (CON=1)
received. RTU
• (CON=1)
• (SEQ=3)
time-out. Resend
• (SEQ=3)
•
response.
•
•
•
Figure 3-5 Multi-Fragment Response & RTU Confirmation Time-out
From the Outstation side, Case Five is identical to Case Four. In Case Five unlike Case
Four, the master does CONFIRM the first Outstation response. This CONFIRMation is
not received by the Outstation. When the Outstation resends the response, the master will
repeat the CONFIRMation. The master will not re-process the second response.
Case Six illustrates the case where the master request is not received by the Outstation.
The master repeats the request after a response time-out occurs.
DNP V3.00 Application Layer (Version 0.03)
3-5
CASE 5
Time
••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••→
Master
• Request.
•
•
• Response
• CONFIRM
• CONFIRM
• expected.
• (SEQ=10)
• (SEQ=10)
• (CON=0)
•
•
• (SEQ=10)
•
•
▼
▼
▼
-------------------------------------------------------------------Outstation
▲
▲
• Response
CONFIRM not
• Response
• (CON=1)
received. RTU
• (CON=1)
• (SEQ=10)
time-out. Resend
• (SEQ=10)
•
response.
•
•
•
CASE 6
Time
••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••→
Master
• Request.
Time-out on
• Request.
•
• Response
response.
• Response
• CONFIRM
• expected.
Resend
• expected.
• (SEQ=5)
• (CON=0)
Request.
• (CON=0)
•
• (SEQ=5 )
• (SEQ=5)
•
▼
▼
▼
-------------------------------------------------------------------Outstation
▲
Request not
• Response
received.
• (CON=1)
• (SEQ=5)
•
•
Figure 3-6 Message Transactions With Response Time-outs
Case Seven is similar to Case Four. In both cases, the Outstation response to the master
request is not received. In Case Four the Outstation timed out waiting for the
CONFIRMation and repeated the response. In Case Seven however, the master times out
first and repeats the request. The Outstation automatically stops waiting for the
CONFIRMation and repeats its previous response. Case Seven also illustrates another
possible condition. The original response that the master did not receive is delayed in the
communication network. The master re-sends the request, the Outstation replies and the
master finishes the transaction sequence with a CONFIRMation. The original response
from the Outstation then arrives at the master station. The master station assumes that the
first CONFIRMation was not received by the Outstation. It therefore re-transmits the
CONFIRMation. The Outstation receives and discards this second CONFIRMation.
Case Eight is similar to Case Seven. In this case, the first CONFIRMation from the
Outstation is delayed in the communication network. When this CONFIRMation
eventually arrives at the master station, it is ignored.
3-6
DNP Users Group
CASE 7
Time
••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••→
Master
• Request.
Response
• Request.
•
•
• Response
not received. • Response
• CONFIRM
• CONFIRM
• expected. Resend
• expected. • (SEQ=8)
• (SEQ=8)
• (CON=0)
request.
• (CON=0)
•
•
• (SEQ=8)
• (SEQ=8)
•
•
▼
▼
▼
▼
-------------------------------------------------------------------Outstation
▲
▲
• Response
• Response
RTU ignores
• (CON=1)
• (CON=1)
second
• (SEQ=8)
• (SEQ=8)
CONFIRM
•
•
•
•
CASE 8
Time
••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••→
Master
• Request.
CONFIRM delayed
• Request.
Master receives
• No response in network.
• No response
first delayed
• expected.
Time-out. Master
• expected.
CONFIRM and
• (CON=0)
resends request. • (CON=1)
ignores it.
• (SEQ=5 )
• (SEQ=12)
▼
▼
-------------------------------------------------------------------Outstation
▲
▲
• CONFIRM
• CONFIRM
• (SEQ=12)
• (SEQ=12)
•
•
•
•
•
•
Figure 3-7 Message Flow When Response Delayed on a Network
In Case Nine, the Unsolicited Response is re-transmitted by the Outstation when a timeout on the CONFIRMation occurs. The master eventually receives it twice. It does not
process it the second time, but does respond to it in the same way as the first time. The
Outstation discards the second CONFIRMation. This illustrates a situation where
network delays, and not message losses, cause time-outs to occur.
CASE 9
Time
••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••→
Master
Unsol. response
•
Master
•
delayed in
• CONFIRM
receives the
• CONFIRM
network.
• (SEQ=30)
delayed unsol.
• (SEQ=30)
Not received.
•
response.
•
•
Resend CONFIRM. •
▼
▼
-------------------------------------------------------------------Outstation ▲
▲
• Unsol.
Time-out on • Unsol.
RTU discards
• response. CONFIRM
• Response.
second
• (CON=1)
Resend.
• (CON=1)
CONFIRM.
• (SEQ=30)
• (SEQ=30)
•
•
Figure 3-8 Resending Unsolicited Responses Due to Network Delays
DNP V3.00 Application Layer (Version 0.03)
3-7
3.3 MASTER REQUEST & UNSOLICITED RESPONSE
COLLISIONS
When Unsolicited Responses are generated by an Outstation there exists the possibility
that the master station sends a request at the same time that the Outstation sends an
Unsolicited Response. The Outstation may receive the request when it expects to receive
a CONFIRMation of its Unsolicited Response. The master receives the Unsolicited
Response when it expects to receive a response to its request.
The processing of the above and similar situation depends on the type of request issued
by the master station.
The master station will always process an Unsolicited Response immediately, ever if it
arrives when the master station is expecting a response to a previously issued request. A
CONFIRMation of the Unsolicited Response is issued immediately if requested by the
Outstation (i.e. if CON bit is set).
The Outstation will generally process a request immediately, even if it is waiting for
CONFIRMation of a previous Unsolicited Response. All requests except READ requests
for system data (e.g. Binary input data, counter event data etc.) are processed in this way.
This mode of operation is referred to as IMMEDIATE_PROCESS mode.
The Outstation will NOT process a master station READ request if it is waiting for
CONFIRMation of a previous Unsolicited Response. It will wait for the CONFIRMation
before processing the request. The reason for the different functionality is to prevent the
loss or duplication of data events. This mode of operation is referred to
PROCESS_AFTER_CONFIRM mode.
3.3.1 IMMEDIATE_PROCESS Mode
Figures 3-9 and 3-10 illustrate the normal functionality when a master station request and
an Outstation Unsolicited Response are transmitted simultaneously and the Outstation is
in the IMMEDIATE_PROCESS mode (i.e. request is not a READ request).
In Case Ten, the master immediately responds to the Unsolicited Response. The
Outstation immediately processes and responds to the master station request. Note that
the two CONFIRMation responses could be sent from the master in the opposite order to
the order shown in Case Ten. This would not confuse the Outstation.
Case Eleven illustrates a basic message flow where the Unsolicited Response does not
require a CONFIRMation.
3-8
DNP Users Group
CASE 10
Time
••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••→
Master
• Request.
•
•
• Response
• CONFIRM
• CONFIRM
• expected.
• (SEQ=7)
• (SEQ=24)
• (CON=0)
•
•
• (SEQ=7)
•
•
▼
▼
▼
-------------------------------------------------------------------Outstation ▲
▲
• Unsol.
• Response
• Response
• to master
• (CON=1)
• request
• (SEQ=24)
• (CON=1)
•
• (SEQ=7)
CASE11
Time
••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••→
Master
• Request.
Store and
•
• Response
process the
• CONFIRM
• expected.
unsol. response.
• (SEQ=2)
• (CON=1)
•
• (SEQ=2)
•
▼
▼
-------------------------------------------------------------------Outstation ▲
▲
▲
• Unsol.
• CONFIRM
• Response
• response
• (SEQ=2)
• to master
• (CON=0)
•
• request
• (SEQ=22)
•
• (CON=1)
•
•
• (SEQ=2)
Figure 3-9 Simultaneous Transmissions, IMMEDIATE_PROCESS Mode
In Case Twelve, the Unsolicited Response is CONFIRMed in between CONFIRMations
to two fragments of a multi-fragment response to the master request.
Case Thirteen illustrates the situation where the Unsolicited Response is not received by
the master station. The Outstation responds to the master request, then after the
CONFIRMation time-out for the Unsolicited Response, the Outstation re-transmits the
Unsolicited Response. The master then CONFIRMs the Unsolicited Response. Note that
it is possible that the first Unsolicited Response later arrives at the master station (it was
delayed in the network). The master would not re-process the response, but would reply
to it again. The Outstation would discard the reply.
DNP V3.00 Application Layer (Version 0.03)
3-9
CASE 12
Time
••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••→
Master
• Request.
•
•
•
• Response
• CONFIRM
• CONFIRM
• CONFIRM
• expected.
• (SEQ=2)
• (SEQ=18)
• (SEQ=3)
• (CON=0)
•
•
•
• (SEQ=2)
•
•
•
▼
▼
▼
▼
-------------------------------------------------------------------Outstation ▲
▲
▲
• Unsol.
• Response
• Response
• Response
• Frag. 1
• Frag. 2
• (CON=1)
• (CON=1)
• (CON=1)
• (SEQ=18)
• (SEQ=2)
• (SEQ=3)
•
•
•
CASE 13
Time
••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••→
Master
• Request.
Master does
•
•
• Response
not receive
• CONFIRM
• CONFIRM to
• expected.
unsol. response.
• (SEQ=3)
• unsol.
• (CON=0)
•
• response
• (SEQ=3)
•
• (SEQ=28)
▼
▼
▼
-------------------------------------------------------------------Outstation ▲
▲
▲
• Unsol.
• Response
RTU time-out for
• Unsol.
• response
• (CON=1)
CONFIRM to unsol.
• response
• (CON=1)
• (SEQ=3)
response. Resend
• (CON=1)
• (SEQ=28)
•
request.
•
•
•
•
Figure 3-10 Simultaneous Transmissions, IMMEDIATE_PROCESS Mode
3.3.2 PROCESS_AFTER_CONFIRM Mode
When a READ request for system data is received by the Outstation and a previous
Unsolicited Response has not yet been CONFIRMed, the Outstation will not process the
READ request until it receives the CONFIRMation to the Unsolicited Response. If the
Outstation was to respond to the READ request immediately, there is a risk of data being
lost or duplicated. This is due to the possibility that the READ request requests data
objects which are already in the unCONFIRMed Unsolicited Response.
Case Fourteen illustrates the situation where the READ request is received while the
Outstation is waiting for a CONFIRMation. The Outstation will not process the READ
request until the CONFIRMation is received.
Case Fifteen is similar to Case Fourteen except the Unsolicited Response is not
CONFIRMed. The Outstation must re-transmit the Unsolicited Response until it is
CONFIRMed or its configured re-transmission limit is reached. If this limit is ever
reached, the Outstation will internally re-buffer the data in the Unsolicited Response,
respond to any outstanding master station requests then try to send the Unsolicited
Response again.
3-10
DNP Users Group
CASE 14
Time
••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••→
Master
• Request.
•
•
• Response
• CONFIRM
• CONFIRM
• expected.
• to unsol.
• (SEQ=2)
• (CON=0)
• response
•
• (SEQ=2)
• (SEQ=18)
•
▼
▼
▼
-------------------------------------------------------------------Outstation ▲
RTU waits
RTU now
▲
• Unsol.
for confirm
processes
• Response
• Response
Do not process
master
• (CON=1)
• (CON=1)
request.
request.
• (SEQ=2)
• (SEQ=18)
•
•
•
CASE 15
Time
••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••→
Master
• Request.
Master does
•
•
• Response
not receive
• CONFIRM to
• CONFIRM
• expected.
unsol. response.
• unsol.
• (SEQ=3)
• (CON=0)
• response
•
• (SEQ=3)
• (SEQ=28)
•
▼
▼
▼
-------------------------------------------------------------------Outstation ▲
▲
▲
• Unsol.
RTU time-out for
• Unsol.
• Response
• response
CONFIRM to unsol. • response
• (CON=1)
• (CON=1)
response. Resend
• (CON=1)
• (SEQ=3)
• (SEQ=28)
unsol. response.
• (SEQ=28)
•
•
•
•
Figure 3-11 Simultaneous Transmissions, PROCESS_AFTER_CONFIRM Mode
3.4 ERROR RECOVERY
The DNP application layer relies on the data link layer for all message transmission,
reception and error checking. The application layer is NOT responsible for recovering
from communication problems. When and if a transaction failure is reported by the data
link layer, the application layer should fail the application layer transaction and report the
error to the user. In addition, the master application layer should indicate the value of the
Internal Indications in all Outstation responses. The user layer is responsible for initiating
any kind of error recovery procedure. In particular, the user layer should make use of the
IIN or Internal Indications that are returned in any Outstation response.
DNP V3.00 Application Layer (Version 0.03)
3-11
3.5 FUNCTION CODES
The function code identifies the purpose of the message. The size of this field is one
octet. There are two groups of function codes; one for requests and the other for
responses.
CODE
FUNCTION
DESCRIPTION
Transfer Function Codes
0
Confirm
Message fragment confirmation used in
both requests and responses. No
response to this message is required.
1
Read
Request specified objects from Outstation;
respond with objects requested that are
available.
2
Write
Store specified objects in Outstation;
respond with status of the operation
Control Function Codes
3
Select
Select or arm output points but do not set
or produce any output action (controls,
setpoints, analog outputs) ; respond with
the status of the control points selected.
The Operate function code is required to
activate these outputs.
4
Operate
Set or produce the output actions on the
points previously selected with the Select
function; respond with the status of the
control points.
5
Direct Operate
Select and set or operate the specified
outputs; respond with the status of the
control points.
6
Direct Operate
- No
Acknowledgment
Select and set or operate the specified
outputs but do not send a response to the
request.
Freeze Function Codes
7
Immediate Freeze
Copy the specified objects to a freeze
buffer and respond with status of the
operation.
8
Immediate Freeze
-No Acknowledgment
Copy the specified objects to a freeze
buffer; do not respond with a message.
Transfer Function Codes
9
3-12
Freeze and Clear
Copy the specified objects to a freeze
buffer, then clear the objects; respond with
the status of the operation.
DNP Users Group
CODE
FUNCTION
DESCRIPTION
10
Freeze and Clear
-No Acknowledgment
Copy the specified objects to a freeze
buffer, then clear the objects; do not
respond with a message.
11
Freeze with Time
Copy the specified objects to a freeze
buffer at the specified time and intervals;
respond with the status of the operation.
12
Freeze with Time
-No Acknowledgment
Copy the specified objects to a freeze
buffer at the specified time and intervals;
do not respond with a message.
Application Control Function Codes
13
Cold Restart
Perform the desired reset sequence;
respond with a time object indicating time
till Outstation availability.
14
Warm Restart
Perform the desired partial reset sequence;
respond with a time object indicating time
till Outstation availability.
15
Initialize Data to
Defaults
Initialize the specified data to power up
initial values; respond with status of the
operation.
16
Initialize Application
Ready the specified application(s) to run;
respond with status of the operation.
17
Start Application
Start running the specified application(s);
respond with status of the operation.
18
Stop Application
Stop the specified application(s); respond
with status of the operation.
Configuration Function Codes
19
Save Configuration
Save the specified configuration to nonvolatile memory; respond with a time object
indicating time till Outstation availability.
20
Enable Unsolicited
Messages
Enable spontaneous reporting of the
specified data object(s); respond with
status of the operation
21
Disable Unsolicited
Messages
Disable spontaneous reporting of the
specified data object(s); respond with
status of the operation
22
Assign Class
Assigned specified data object(s) to a
particular class
Time Synchronization Function Codes
23
Delay Measurement
Allows the application to calculate the path
delay (or propagation delay) for a particular
Outstation. The value calculated from this
function code should be used to adjust the
time of day when setting the Outstation
time.
DNP V3.00 Application Layer (Version 0.03)
3-13
CODE
FUNCTION
DESCRIPTION
Reserved
24 - 120
Reserved for future use
121 - 128
Reserved for testing only
Response Function Codes
0
Confirm
Message fragment confirmation used in
both requests and responses. No response
to this message is required.
129
Response
Response to a request message
130
Unsolicited Message
Unsolicited response that was not
prompted by a request.
Table 3-1 Function Codes
3.6 INTERNAL INDICATIONS
The Internal Indications (IIN) field is a two-octet field that follows the function code in
all responses. When a request cannot be processed due to formatting errors or the
requested data is not available, the IIN is always returned with the appropriate bits set.
••••••••••••••••••••••••••••••
• First Octet
Second Octet •
•
|
•
••••••••••••••••••••••••••••••
First Octet
•••••••••••••••••••••••••••••••••••••••••••••••••
• 7 • 6 • 5 • 4 • 3 • 2 • 1 • 0 • Bit number
•
•
•
•
•
•
•
•
•
•••••••••••••••••••••••••••••••••••••••••••••••••
A one (1) in the bit position indicates the described state.
Bit 0
-
Bit 1
-
Bit 2
3-14
-
All stations message received
Set when a request is received with the destination address of the
all stations address (ffff hexadecimal).
Cleared after next response (even if response to global request is
required)
Used to let the master station know that a Broadcasted message
was received by this station.
Class 1 data available
Set when data that has been configured as Class 1 data is ready to be sent
to the master
Master station should request this class data from the Outstation when this
bit is set in a response
Class 2 data available
DNP Users Group
Bit 3
-
Bit 4
-
Bit 5
-
Bit 6
-
Bit 7: -
Set when data that has been configured as Class 2 data is ready to be sent
to the master
Master station should request this class data from the Outstation when this
bit is set in a response
Class 3 data available
Set when data that has been configured as Class 3 data is ready to be sent
to the master
Master station should request this class data from the Outstation when this
bit is set in a response
Time-synchronization required from the master. The master synchronizes
the time by writing the Time and Date object to the Outstation.
Cleared when the time is set by the master. This bit is also cleared when
the master explicitly writes a 0 into this bit of the Internal Indication object
of the Outstation.
Set when some or all of the Outstation's digital output points are in the
Local state. That is, the Outstation's control outputs are NOT accessible
through the DNP protocol.
Clear when the Outstation is in the Remote state. That is, the Outstation's
control outputs are accessible through the DNP protocol.
Device trouble
Set when an abnormal condition exists at the Outstation. The device
profile for a given device states the conditions that effect this bit.
This should only be used when the state can not be described by a
combination of one or more of the other IIN bits.
Device restart
Set when the user application at the Outstation restarts.
Cleared when the master explicitly Writes a 0 into this bit of the Internal
Indications object in the Outstation.
Second Octet
•••••••••••••••••••••••••••••••••••••••••••••••••
• 7 • 6 • 5 • 4 • 3 • 2 • 1 • 0 • Bit number
•
•
•
•
•
•
•
•
•
•••••••••••••••••••••••••••••••••••••••••••••••••
Bit 0
-
Function code not implemented
Bit 1
-
Requested object(s) unknown. The Outstation does not have the specified
objects or there are no objects assigned to the requested class.
This indication should be used for debugging purposes and usually
indicates a mismatch in device profiles or configuration problems.
-
DNP V3.00 Application Layer (Version 0.03)
3-15
Bit 2
-
Bit 3
-
Parameters in the qualifier, range or data fields are not valid or out of
range. This is a catch-all for application request formatting errors.
This indication should be used for debugging purposes and usually
indicates configuration problems.
-
Event buffer(s), or other application buffers have overflowed. For
example, COS/SOE buffers have overflowed.
The master should attempt to recover as much data as possible and
indicate to the user that their may be lost data. The appropriate error
recovery procedures should be initiated by the user.
Bit 4
-
Request understood but requested operation is already executing.
Bit 5
-
Set to indicate that the current configuration in the Outstation is corrupt
and that the master application layer should inform the user of this
exception. The master may download another configuration to the
Outstation. Note that sometimes a corrupt configuration will disable an
Outstation, making it impossible to communicate this condition to a
master station.
Bit 6
-
Reserved for use by agreement, currently always returned as zero (0).
Bit 7
-
Reserved for use by agreement, currently always returned as zero (0).
3.7 OBJECT HEADER
The object header of a message specifies the data objects (or IOs) that are either contained
in the message or are to be used to respond to this message. The format of the object
header is identical for a request and a response but the interpretation of the header is
dependent on whether it is a request or a response and which function code accompanies
the header.
••••••••••••••••••••••••••••••
• Object • Qualifier • Range •
•
•
•
•
••••••••••••••••••••••••••••••
Figure 3-12 Object Header
Object
Specifies the object group and variation of the objects that follow the
header as described in section 3. OBJECT. This is a two-octet field. The
object field uniquely identifies the type or class of object which gives the
structure (and hence size) of the data object.
Qualifier
Specifies the meaning of the range field as described in section 3.
QUALIFIER. This is a one-octet field. The qualifier specifies how the
range field is to be interpreted.
3-16
DNP Users Group
Range
Indicates the quantity of objects, starting and ending index or identifiers
for the objects in question as described in section 3. This field uniquely
identifies the objects in question.
NOTE:
The range field may not be present if the qualifier specifies that there is no
range field. The size of this field ranges from zero (0) octets to eight
octets.
3.7.1 Object Field
The Object field specifies an object group and the variation of the object within the
group. The combined object group plus variation specifies uniquely the object to which
the message refers. The currently defined object structures are described in DNP-V3.00
Data Object Library (P009-0BL).
Objects may be assigned to one of four classes. When the Object field specifies a data
class instead of a specific object type, the object field refers indirectly to all the data
objects assigned to that class of data and not to any specific object type. See Section 5:
CLASSES for more detail.
The object field is two octets in length. The first octet specifies the general type of data
(e.g. analog inputs) and the second octet specifies the variation of the data type (e.g. 16bit analog inputs or 32-bit analog inputs). In the request direction, if the object variation
is specified as 0, this indicates all object variations belonging to the same group (i.e. all or
any analog inputs types). In the response direction however, variation 0 cannot be used to
specify the objects. The specific variation has to be specified.
Consider the example where the request message specifies counter objects in the first
octet and the variation is 0. Given that the Outstation supports only 16 bit counters, it
will respond with an object header with the variation field set to indicate that the counter
objects are 16 bit counters.
With the same request message directed to another station, the returned object header may
indicate a 32 bit count field in the counter objects it returns. By requesting data with the
variation set to 0, it is not necessary for the master to know what variations the Outstation
supports. The master must however be able to interpret the object headers and have some
knowledge of the structure of each variation.
first octet
second octet
•••••••••••••••••••••••••••••••••••••••••
•
• 0 or Object variation•
• Object Group ••••••••••••••••••••••••
•
• Object variation
•
•••••••••••••••••••••••••••••••••••••••••
Application request direction
Application response direction
Figure 3-13 Object Field
DNP V3.00 Application Layer (Version 0.03)
3-17
3.7.2 Qualifier Field
The qualifier field specifies the meaning of the range field.
7
6
5
4
3
2
1
0
bit
••••••••••••••••••••••••••••••••••••••••••••••••••
• R •
Index Size
• 4 bit Qualifier Code •
•
•
•
•
••••••••••••••••••••••••••••••••••••••••••••••••••
Figure 3-14 Qualifier Field
R
Reserved bit always set to 0
The Range Field is used to index data or as an identifier. The structure and use of the
Range Field is dependent on the value in the Index Size field and the Qualifier Code field.
When the Range Field is used to index data, it often consists of a Start Range value and
an Stop Range value. Together they define a range of objects in the data following the
Object Header. Each of the Start Range and Stop Range sub-fields is termed as index.
Index Size (3-bits)
• In a Request Object Header when Qualifier Code equals 11
The Index Size bits are valid only when the qualifier code is 11. These bits
indicate the size, in octets, of each entry in the Range Field. The Range Field
follows the Qualifier Field. The Range Field consists of indices (to specify a
range of objects) or object identifier lists (see qualifier code 11).
0=
1=
2=
3=
4=
5=
6=
7=
not valid with qualifier code 11
1 octet identifier size
2 octet identifier size
4 octet identifier size
reserved
reserved
reserved
reserved
• In a Response or Request Object Header that is part of a message containing data
objects.
The 3 bit Index Size field specifies the size of the indices or object size prefixing
each object.
0=
1=
2=
3=
4=
3-18
objects are packed with no index prefixing them
objects are prefixed with a 1 octet index
objects are prefixed with a 2 octet index
objects are prefixed with a 4 octet index
objects are prefixed with a 1 octet object size
DNP Users Group
5=
6=
7=
objects are prefixed with a 2 octet object size
objects are prefixed with a 4 octet object size
reserved
Qualifier Code (4-bits)
The Qualifier Code is used to specify the meaning of the Range field.
• Start and Stop Sub-Fields in the Range Field
The Range field following the Qualifier field often contains sub-fields (Start
Range and Stop Range) that designate a range of integer values starting
numerically from Start Range (including the number Start Range) to Stop Range
(including the number Stop Range).
For Qualifier Codes 0, 1 and 2, Start Range and Stop Range are interpreted as
indices of data
For Qualifier Codes 3, 4 and 5, Start Range and Stop Range are interpreted as
virtual memory addresses.
The Qualifier Code can be used both in the request and response messages as it
can uniquely identify data objects whether they do or do not exist in the message.
The Index Size field should be 0 in a data-less message to indicate no further
indexing. The Index Size field can be 4, 5 or 6 in a message with data objects to
indicate that each data object (with indices specified by the Range Field) has an
object size prefix (with this size determines by the Index size). A message with
data can also use Index size of 0 to indicate no more indexing. For Qualifier
Codes specifying Start ad Stop Indices in the Range, Index Size values of 1, 2 and
3 cannot be used.
Some Qualifier Code definitions are:
0=
1=
2=
3=
4=
5=
8 bit start and stop indices in the Range Field
16 bit start and stop indices in the Range Field
32 bit start and stop indices in the Range Field
8 bit absolute address identifiers in the Range
16 bit absolute address identifiers in the Range
32 bit absolute address identifiers in the Range
• All objects of the given object type
When the Qualifier Field equals 6, the length of the range field is 0 (i.e. no range
field) because all the data objects of the specified type are being referred to. This
qualifier can be used in messages with object headers only because it cannot
DNP V3.00 Application Layer (Version 0.03)
3-19
uniquely identify data objects if they are present in the message. The Index size
should be set to 0 when this Qualifier code is used.
Qualifier Code 6 = no range field (implies all the specified objects)
• Single field quantity
Qualifier Codes 7, 8 and 9 are used to indicate that the Range Field consists of a
single count indicating the number of data objects in question. The Range Field
that follows designates the number of objects referenced.
If the Index Size field equals zero, the Range Field specifies the number of objects
referenced starting numerically from 0 (including 0) to the value in the Range
Field minus 1.
If the Index Size is 1, 2 or 3 then the Range Field specifies the number of indices
and objects following the Range Field.
Qualifier Codes 7, 8 and 9 can be used in the request and response messages. In a
message with or without data objects, the value in the Range Field specifies the
number of data objects to be referred to. The Index Size field should be set to the
size of the indices that either pre-fix each data object (for messages with data
objects) or that form a sequential list of identifiers.
The Index Size field should not indicate an object size identifier as this would not
uniquely specify the data objects in question and should be set to 0 if no
identifiers or indices are following. The order of identifiers (and optional data
objects) is arbitrary but should not consist of duplicate indices.
Some Qualifier Code definitions are:
7=
8=
9=
8 bit single field quantity
16 bit single field quantity
32 bit single field quantity
• Free-format Qualifier (Qualifier Code 11)
This Qualifier Code is used to specify objects when other Qualifier Codes are
inadequate or do not provide enough identifying information.
Qualifier 11 is used only when the Range Field (index) cannot uniquely specify
the data objects in question. In this case, the Qualifier Code defines a variable
length array of octets (string) that contains the object identifier.
This identifier has a free-format and will not be interpreted in any way by the
application layer at this time.
3-20
DNP Users Group
The Range Field is always a 1 octet value (Count) which specifies the number of
object identifiers. Following the Range Field are Count object size field/object
identifier pairs. The size of the identifier (in octets) is determined by the object
size field which prefixes each identifier. The size of the object size field is
determined by the Index size. Index sizes 4,5, and 6 should be used to specify the
size of the object size field in octets.
• Reserved Qualifier Codes
The following Qualifier Code values are reserved and should not be used:
10 =
12 =
13 =
14 =
15 =
reserved
reserved
reserved
reserved
reserved
3.7.3 Range
The meaning of the Range Field is specified by the Qualifier Field. For Qualifier Codes 0
to 5 the Range field has 2 sub-fields specifying a start and stop index or address. The
values in these fields are inclusive. The Range field is not present for qualifier code 6.
The range field is a single field specifying a quantity for qualifier codes 7, 8, 9 and 11. In
the following, the term 'Q-code' refers to the 4 bit Qualifier Code field and 'I-size' refers
to the Index Size field.
The following figure defines all the valid qualifier/range/index combinations for a request
or response which do NOT contain any IO or data objects and simply specifies the objects
in question. The bytes described appear after the qualifier octet of the object header and
before the next object header or end of message.
Request for known points specified with a Range of indices.
Use Q-code 0-5 for describing points related in sequence:
•••••••••••••••••••••
• Start • Stop
•
• 8 bit • 8 bit •
•
•
•
•
I1
•
I2
•
•••••••••••••••••••••
Q-code 0 and 3; I-size MUST be 0
Definition of Range Field.
Points are I1 to I2 inclusive
LSB
MSB
LSB
MSB
•••••••••••••••••••••••••••••••••••••••••
•
16 bit Start •
16 bit Stop
•
•
•
•
•
•
•
•
•
•
•
•
I1
•
I2
•
•
•
•
•••••••••••••••••••••••••••••••••••••••••
Q-code 1 and 4; I-size MUST be 0
Points are I1 to I2 inclusive
DNP V3.00 Application Layer (Version 0.03)
3-21
LSB
MSB
LSB
MSB
•••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••
•
32 bit Start
•
32 bit Stop
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
I1
•
I2
•
•
•
•
•••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••
Q-code 2 and 5; I-size MUST be 0
Points are I1 to I2 inclusive
Use Q-code 6 for describing ALL points of the given data type:
(There is no range field or indices with this qualifier
Use Q-code 7-9 for describing a number of unrelated points:
•••••••••••
•Quantity •
• 8 bit •
•
•
•
Q
•
•
•
•••••••••••
Q-code 7; I-size MUST be 0
Points are 0 .. Q-1 inclusive
••••••••••••••••••••
•Quantity • Index •
•
• Index •
• 8 bit •
•
•
•
I1
•
•
Q
•
•
•
• LSB
•
••••••••••••••••••••
••••••••••
•
•
•
•
•
•
....... •
IQ
•
•
•
• LSB
•
••••••••••
••••••••••••••••••••••••••
•Quantity •
Index
•
• 8 bit •
•
•
•
I1
•
•
Q
•
•
•
• LSB • MSB
•
••••••••••••••••••••••••••
•••••••••••••••
•
Index
• Q-code 7; I-size MUST be 2
•
• Points are I1, I2 .. IQ inclusive
.......•
IQ
•
•
•
• LSB • MSB •
•••••••••••••••
•••••••••••••••••••••••••••••••••
•Quantity •
Index
•
• 8 bit •
•
•
•
I1
•
•
Q
•
•
•
• LSB •
• • MSB
•
•••••••••••••••••••••••••••••••••
LSB
MSB
•••••••••••••••••••••
•
16 bit Quantity •
•
Q
•
•
•
•
•••••••••••••••••••••
Q-code 7; I-size MUST be 1
Points are I1, I2 .. IQ inclusive
.......
••••••••••••••••••••
•
Index
•
•
•
•
IQ
•
•
•
• LSB • • • MSB •
••••••••••••••••••••
Q-code 8; I-size MUST be 0
Points are 0 to Q-1 inclusive
LSB
MSB
••••••••••••••••••••••••••••
•
16 bit Quantity • Index•
•
|
• LSB •......
•
•
•
•
Q
• I1 •
••••••••••••••••••••••••••••
•••••••••
• Index •
• LSB •
•
•
• IQ
•
•••••••••
Q-code 8; I-size MUST be 1
Points are I1,I2 .. IQ inclusive
LSB
MSB
•••••••••••••••••••••••••••••••••
••••••••••••••
•
16 bit Quantity •
Index •
•
Index
•
•
•
• LSB • MSB•......• LSB • MSB•
•
•
•
•
•
•
•
•
Q
•
I1
•
•
IQ
•
•••••••••••••••••••••••••••••••••
••••••••••••••
Q-code 8; I-size MUST be 2
Points are I1,I2 .. IQ inclusive
LSB
MSB
•••••••••••••••••••••••••••••••••••••••
••••••••••••••••••••
•
16 bit Quantity •
Index
•
•
Index
•
•
•
• LSB • • • MSB•......• LSB • • • MSB•
•
•
•
• • •
•
•
• • •
•
•
Q
•
I1
•
•
IQ
•
•••••••••••••••••••••••••••••••••••••••
••••••••••••••••••••
3-22
Q-code 7; I-size MUST be 3
Points are I1, I2 .. IQ inclusive
Q-code 8; I-size MUST be 3
Points are I1,I2 .. IQ inclusive
DNP Users Group
LSB
MSB
•••••••••••••••••••••••••••••••••••••••••
•
32 bit Quantity
•
•
•
|
•
•
•
•
IQ
•
•
•••••••••••••••••••••••••••••••••••••••••
Q-code 9; I-size MUST be 0
Points are 0 .. IQ-1
LSB
MSB
••••••••••••••••••••••••••••••••••••••••••••••••••
••••••••••
•
32 bit Quantity
• Index •
• Index •
•
|
|
|
•
LSB
•....• LSB
•
•
Q
•
I1
•
•
IQ
•
••••••••••••••••••••••••••••••••••••••••••••••••••
••••••••••
Q-code 9; I-size MUST be 1
Points are I1, I2 .. IQ
LSB
MSB
••••••••••••••••••••••••••••••••••••••••••••••••••••
•••••••••••••
•
32 bit Quantity
• Index
•
•
Index •
•
|
|
|
• LSB | MSB •....• LSB | MSB •
•
Q
•
I1
•
•
IQ
•
••••••••••••••••••••••••••••••••••••••••••••••••••••
•••••••••••••
Q-code 9; I-size MUST be 2
Points are I1, I2 .. IQ
LSB
MSB
••••••••••••••••••••••••••••••••••••••••••••••••••••••••••
•••••••••••••••••••
•
32 bit Quantity
•
Index
•
• Index
•
•
|
|
|
• LSB | | | MSB •....• LSB | | | MSB •
•
Q
•
I1
•
•
IQ
•
••••••••••••••••••••••••••••••••••••••••••••••••••••••••••
•••••••••••••••••••
Q-code 9; I-size MUST be 3
Points are I1, I2 .. IQ
Use qualifier 11 when describing points that need to be uniquely identified by an object identifier such as a
File Object Identifier or Configuration Header. The type of identifier is implied by the object type:
••••••••••••••••••••••••••••••
••••••
••••••••••••••
••••••
• 8-bit • 8-bit •
•
•
•
•
• 8-bit •
•
•
•
•
•
• O11 • O12• .... • O1N•...•
• OQ1•...• OQN•
•
Q
•Size N1•
•
•
•
•
•Size NQ•
•
•
•
••••••••••••••••••••••••••••••
••••••
••••••••••••••
••••••
Q-code 11; Index size MUST be 1
Octets Oi1 .. OiN form the object identifier for Object i where 0<=i<Q (quantity)
••••••••••••••••••••••••••••••••••••
••••••
•
16-bit •
16-bit •
•
•
•
•
• LSB | MSB • LSB | MSB • O1 • O2 • .... • ON •
•
Q
• Size N
•
•
•
•
•
••••••••••••••••••••••••••••••••••••
••••••
Q-code 11; I-size MUST be 2
Octets 1 to N are the object identifier
As for the previous case, there could be many identifiers each one following the other.
••••••••••••••••••••••••••••••••••••••••••••••••
••••••
•
32-bit
•
32-bit
•
•
•
•
•
• LSB | | | MSB • LSB | | | MSB • O1 • O2 • .... • ON •
•
Q
•
Size N
•
•
•
•
•
••••••••••••••••••••••••••••••••••••••••••••••••
••••••
Q-code 11; I-size MUST be 3
Octets 1 to N are the object identifier
As for the previous case, there could be many identifiers each one following the other.
Figure 3-15 Messages Without Data Objects
DNP V3.00 Application Layer (Version 0.03)
3-23
The following figure defines all the valid qualifier/range/index combinations for a request
or response which contain IO or data objects and specifies that the objects in question
either follow the qualifier/range fields (for qualifier without pre-fixing indices) or follow
each individual identifying index. The bytes described appear after the qualifier octet of
the object header and before the next object header or end of message.
Request/response with known points specified with a Range of indices.
Use Q-code 0-5 for describing points related in sequence:
••••••••••••••••••••••••••••••••••••••••
• Start • Stop
• DO • DO • DO •
• 8 bit • 8 bit •
•
•
•
•
•
• I1 • I1+1 • I1+2 •....
•
I1
•
I2
•
•
•
•
••••••••••••••••••••••••••••••••••••••••
••••••••
• DO •
•
•
• I2 •
•
•
••••••••
Q-code 0 and 3; I-size MUST be 0
Points/Objects are I1 .. I2 inclusive
LSB
MSB
LSB
MSB
••••••••••••••••••••••••••••••••••••••••••••••••
•••••••
•
16 bit Start •
16 bit Stop
• DO
•
• DO • Q-code 1 and 4; I-size MUST be 0
•
|
•
|
•
•
•
• Points/Objects are I1 .. I2 inclusive
•
•
• I1
•....• I2 •
•
I1
•
I2
•
•
•
•
•
•
•
•
•
•
••••••••••••••••••••••••••••••••••••••••••••••••
•••••••
LSB
MSB
LSB
MSB
••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••
•••••••
•
32 bit Start
•
32 bit Stop
• DO •
• DO •
•
|
|
|
•
|
|
|
•
•
•
•
•
•
• I1 •....• I2 •
•
I1
•
I2
•
•
•
•
•
•
•
•
•
•
••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••
•••••••
Q-code 2 and 5; I-size MUST be 0
Points/Objects are I1 .. I2 inclusive
•••••••••••••••••••••••••••••••••••••
• Start • Stop
• Object •DO-I1 •
• 8 bit • 8 bit • Size
• with •
•
•
• 8-bit • size •.....
•
I1
•
I2
•
S1
• S1 •
•••••••••••••••••••••••••••••••••••••
••••••••••••••••
• Object •DO-I2• Q-code 0 and 3; I-size MUST be 4
• Size
• with• Points/Objects are I1 .. I2 inclusive
• 8-bit • size•
• S2
• S2 •
••••••••••••••••
Note: 16 and 32-bit object sizes can also be used by using I-size 5 and 6
LSB
MSB
LSB
MSB
••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••
••••••••••••••••••••
•
16 bit Start •
16 bit Stop
• Object
•DO-I1 •
• Object
•DO-I2 •
•
|
•
|
•
Size
• with •
• Size
• with •
•
•
• 16-bit
• size •
•.16-bit
• size •
•
I1
•
I2
•
S1
• S1 •....•
S2
• S2 •
•
•
• LSB | MSB •
•
• LSB | MSB •
•
••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••
••••••••••••••••••••
Q-code 1 and 4; I-size MUST be 5
Points/Objects are I1 .. I2 inclusive
Note: 8 and 32-bit object sizes can also be used by using I-size 4 and 6
LSB
MSB
LSB
MSB
••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••
•
•
•
•
•
••••••••••••••••••••••••
•
•
•
•
•
•
•
•
•
32 bit Start
•
32 bit Stop
•
Object
• DO-I1•
•
Object
•DO-I2 •
•
|
|
|
•
|
|
|
•
Size
• with •
•
Size
• with •
•
•
•
32-bit
• size •
•
32-bit
• size •
•
I1
•
I2
•
S1
• S1 •...•
S2
• S2 •
•
•
• LSB | | | MSB •
•
• LSB | | | MSB •
•
••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••
••••••••••••••••••••••••
Q-code 2 and 5; I-size MUST be 6
Points/Objects are I1 .. I2 inclusive
Note: 8 and 16-bit object sizes can also be used by using I-size 4 and 5
Important Note !!!
Do NOT use Q-code 6 for describing a message which contains data objects as the exact number of points
are not known and therefore the contents of the message cannot be determined.
3-24
DNP Users Group
Use Q-code 7-9 for describing a number of unrelated points:
•••••••••••••••••
•Quantity • DO •
• 8 bit •
•
•
• I0 •....
•
Q
•
•
•
•
•
•••••••••••••••••
•••••••••••
•
DO
• Q-code 7; I-size MUST be 0
•
• Points/Objects are 0 .. Q-1 inclusive
• I(Q-1) •
•
•
•
•
•••••••••••
••••••••••••••••••••••••••
•••••••••••••••••
•Quantity • Index • DO •
• Index • DO •
• 8 bit •
•
•
•
•
•
•
•
I1
• I1 • ..•
IQ
• IQ •
•
Q
•
•
•
•
•
•
•
• LSB
•
•
• LSB
•
•
••••••••••••••••••••••••••
•••••••••••••••••
Q-code 7; I-size MUST be 1
Points/Objects are I1, I2 .. IQ inclusive
••••••••••••••••••••••••••••••••
•••••••••••••••••••••
•Quantity •
Index
• DO •
•
Index
• DO •
• 8 bit •
•
•
•
•
•
inclusive
•
•
I1
• I1 •....•
IQ
• IQ •
•
Q
•
•
•
•
•
•
•
• LSB | MSB
•
•
• LSB | MSB •
•
••••••••••••••••••••••••••••••••
•••••••••••••••••••••
Q-code 7; I-size MUST be 2
Points/Objects are I1, I2 .. IQ
••••••••••••••••••••••••••••••••••••••
••••••••••••••••••••••••••
•Quantity •
Index
• DO •
•
Index
• DO •
3
•
•
•
•
•
•
•
• 8 bit •
•
•
•
•
•
•
•
I1
• I1 • .....•
IQ
• I1 •
•
•
•
•
•
•
•
•
Q
•
•
•
•
•
•
•
• LSB |
| | MSB
•
•
• LSB | | | MSB •
•
••••••••••••••••••••••••••••••••••••••
••••••••••••••••••••••••••
LSB
MSB
••••••••••••••••••••••••••
•
16 bit Quantity • DO •
•
Q
•
•...
•
|
• I0 •
••••••••••••••••••••••••••
••••••••
• DO
•
•
•
•I(Q-1)•
••••••••
LSB
MSB
•••••••••••••••••••••••••••••••••••
•
16 bit Quantity • Index • DO •
•
|
• LSB
•
•
•
•
• I1 •
•
Q
• I1
•
•
•••••••••••••••••••••••••••••••••••
Q-code 7; I-size MUST be
Points/Objects are
I1, I2 .. IQ inclusive
Q-code 8; I-size MUST be 0
Points/Objects are 0 .. Q-1 inclusive
•••••••••••••••
• Index • DO •
• LSB •
•
•
•IQ
•
• IQ
•
•
•••••••••••••••
Q-code 8; I-size MUST be 1
Points/Objects are I1,I2 .. IQ inclusive
LSB
MSB
••••••••••••••••••••••••••••••••••••••
•••••••••••••••••••
•
16 bit Quantity •
Index • DO •
•
Index
• DO •
•
|
• LSB | MSB•
•......• LSB | MSB•
•
inclusive
•
|
•
• I1 •
•
• IQ •
•
Q
•
I1
•
•
•
IQ
•
•
••••••••••••••••••••••••••••••••••••••
•••••••••••••••••••
Q-code 8; I-size MUST be 2
Points/Objects are I1,I2 .. IQ
LSB
MSB
••••••••••••••••••••••••••••••••••••••••••••
•••••••••••••••••••••••••
•
16 bit Quantity •
Index
• DO •
•
Index
• DO •
3
•
|
• LSB | | | MSB•
•.....• LSB | | | MSB•
•
.. IQ
•
•
• I1 •
•
• IQ •
•
Q
•
I1
•
•
•
IQ
•
•
••••••••••••••••••••••••••••••••••••••••••••
•••••••••••••••••••••••••
LSB
MSB
••••••••••••••••••••••••••••••••••••••••••••••
•
32 bit Quantity
• DO •
•
|
|
|
•
•....
•
IQ
• I1 •
••••••••••••••••••••••••••••••••••••••••••••••
••••••
• DO •
•
•
• IQ •
••••••
Points/Objects are I1,I2
inclusive
Q-code 9; I-size MUST be 0
Points are I1, I2 .. IQ inclusive
LSB
MSB
•••••••••••••••••••••••••••••••••••••••••••••••••••••••
•••••••••••••••
•
32 bit Quantity
• Index • DO •
• Index • DO •
1
•
|
|
|
•
LSB
•
•....• LSB
•
•
•
Q
•
I1
• I1 •
•
I2
• I2 •
DNP V3.00 Application Layer (Version 0.03)
Q-code 8; I-size MUST be
Q-code 9; I-size MUST be
Points are I1, I2 .. IQ
3-25
•••••••••••••••••••••••••••••••••••••••••••••••••••••••
•••••••••••••••
LSB
MSB
•••••••••••••••••••••••••••••••••••••••••••••••••••••••••
•••••••••••••
•
32 bit Quantity
• Index
• DO •
•
Index •
2
•
|
|
|
• LSB | MSB •
•...• LSB | MSB •
•
Q
•
I1
• I1 •
•
I2
•
•••••••••••••••••••••••••••••••••••••••••••••••••••••••••
•••••••••••••
Q-code 9; I-size MUST be
Points are I1, I2 .. IQ
LSB
MSB
••••••••••••••••••••••••••••••••••••••••••••••••••••••••••
•••••••••••••••••••
•
32 bit Quantity
•
Index
•
• Index
•
MUST be 3
•
|
|
|
• LSB | | | MSB •....• LSB | | | MSB •
.. IQ
•
Q
•
I1
•
•
I2
•
••••••••••••••••••••••••••••••••••••••••••••••••••••••••••
•••••••••••••••••••
Q-code 9; I-size
Points are I1, I2
Use qualifier 11 when describing points that need to be uniquely identified by an object identifier
such as a File Object Identifier or Configuration Header. The type of identifier is implied by the
object type:
••••••••••••••••••••••••••••••
••••••••••••
••••••••••••••
•••••••••••
• 8-bit • 8-bit •
•
•
•
• DO •
• 8-bit •
•
•
• DO •
•
•
• O11 • O11• .... • O1N•
•...•
• OQ1•...• OQN•
•
•
Q
•Size N1•
•
•
•
• ID1 •
•Size NQ•
•
•
• IDQ•
••••••••••••••••••••••••••••••
••••••••••••
••••••••••••••
•••••••••••
Q-code 11; Index size MUST be 1
Octets Oi1 .. OiN form the object identifier for Object i where 0<=i<Q (quantity) which is followed by
the object identified. The size of the object is contained in the Object Identifier so the Application
Layer must be able to interpret some fields of the Object Identifier in order to process a message.
••••••••••••••••••••••••••••••••••••
••••••••••••
•
16-bit •
16-bit •
•
•
•
• DO •
• LSB | MSB • LSB | MSB • O1 • O2 • .... • ON •
•
•
Q
• Size N
•
•
•
•
• ID1 •
••••••••••••••••••••••••••••••••••••
••••••••••••
Q-code 11; I-size MUST be 2
Octets 1 to N are the object identifier
As for the previous case, there could be many identifiers each one following the other.
••••••••••••••••••••••••••••••••••••••••••••••••
••••••••••••
•
32-bit
•
32-bit
•
•
•
•
• DO •
• LSB | | | MSB • LSB | | | MSB • O1 • O2 • .... • ON •
•
•
Q
•
Size N
•
•
•
•
• ID1 •
•
•
•
•
•
•
•
•
••••••••••••••••••••••••••••••••••••••••••••••••
••••••••••••
Q-code 11; I-size MUST be 3
Octets 1 to N are the object
identifier
As for the previous case, there could be many identifiers each one following the other.
Figure 3-16 Messages With Data Objects
3-26
DNP Users Group
4. DETAILED FUNCTION CODE
DESCRIPTIONS
This section describes the application layer function codes with examples. The
application headers containing the application control, function code and internal
indication have been omitted from most of the examples but are always present in reality.
The requests and responses are assumed to consist of one fragment each. An example of a
multiple fragment message is illustrated in the description of function code 0.
4.1 CONFIRM (FUNCTION CODE 0)
The confirm function is used to confirm the reception of a message fragment when the
application control field (AC) in the received fragment has the CON bit set. Note the
CON bit in the confirmation message may be set to 0 or 1. This allows the option of
having the confirmation message confirmed. However, any station receiving a message
fragment with the CON bit set MUST respond with a CONFIRMation message BEFORE
sending any other application layer message. In addition, any station that sends a
message fragment with the CON bit set must wait until the CONFIRMation message
arrives before continuing with message fragment transmission or another transaction.
The confirmation response for a single fragment message is illustrated in Figure 4-1.
•••••••••••••••••••••••••••••••••••••••••••
•
Application Control
• Function •
• FIR = 1, FIN = 1, CON = ? • Code = 0 •
•
•
•
•••••••••••••••••••••••••••••••••••••••••••
Figure 4-1 Confirmation Message
••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••
•
Request Header
•
Read request that will result in •
• FIR = 1, FIN = 1, •
a multiple fragment response
•
•
CON = 0
•
•
••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••
• Read request, CON = 0 indicates no application confirmation expected for request.
DNP V3.00 Application Layer (Version 0.03)
4-1
••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••
•
Response Header •
ASDU of first fragment of the response •
• FIR = 1, FIN = 0
•
•
•
CON = 1
•
•
••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••
• First fragment of response. CON = 1 indicates the Outstation is expecting an
application confirmation of the reception of this fragment.
•••••••••••••••••••••••••••••••••••••••••••
•
Request Header
• Function •
• FIR = 1, FIN = 1, CON = 0 • Code = 0 •
•
•
•
•••••••••••••••••••••••••••••••••••••••••••
• Confirmation sent by the requesting station
••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••
•
Response Header •
ASDU of second fragment
•
• FIR = 0, FIN = 0
•
of response
•
•
CON = 1
•
•
••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••
• The second fragment of the response
•••••••••••••••••••••••••••••••••••••••••
•
Request Header
• Function •
• FIR = 1, FIN = 1, CON = 0 • Code = 0 •
•
•
•
•••••••••••••••••••••••••••••••••••••••••
• Confirmation of the second fragment
•••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••
• Response Header
•
ASDU of last fragment of the response •
• FIR = 0, FIN = 1
•
•
•
CON = 1
•
•
•••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••
• The last fragment of the response
•••••••••••••••••••••••••••••••••••••••••••
•
Request Header
• Function •
• FIR = 1, FIN = 1, CON = 0 • Code = 0 •
•
•
•
•••••••••••••••••••••••••••••••••••••••••••
• Confirmation of the last fragment of the response
4.2 READ (FUNCTION CODE 1)
The read function is the basic code used for requesting data objects from a Outstation.
The object, qualifier and range field are coded in such a way that their size can be
calculated allowing requests for multiple objects or ranges to be sent in a single message.
4-2
DNP Users Group
The number of multiple requests allowed in a single message is defined in the device
profile of each device DNP is implemented on.
The read request for a single range of objects is illustrated in Figure 4-2. Figure 4-3
illustrates the request for 2 object types or possibly 2 ranges of the same object type.
••••••••••••••••••••••••••••••••••••••••••••••••••
• Request Header • Object • Qualifier • Range •
• AC • FC = 1 •
•
•
•
•
•
•
•
•
•
••••••••••••••••••••••••••••••••••••••••••••••••••
Figure 4-2 Single Object Request
•
first Read request
•
second Read request
•
•••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••
• Request Header • Object • Qualifier • Range • Object • Qualifier • Range •
•
AC | FC = 1 •
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••
Figure 4-3 Multiple Objects or Ranges
4.2.1 Read Requests
The following examples illustrate some legal qualifier and range combinations for the
read function code.
octet 1
2
3
4
5
••••••••••••••••••••••••••••••••••••••••••••••••
•
•
• Object gv
• Qualifier •
• AC • FC = 1 • g = n
v = 0 • 0000 0110 •
•
•
•
|
•
0
6
•
••••••••••••••••••••••••••••••••••••••••••••••••
• Read object group n.
• The qualifier code specifies all the defined objects of the group defined at the
Outstation. This qualifier code also indicates the range field is not present.
• The index size has no meaning and is set to 0.
• The Outstation may respond with any or all objects of the defined group. This method
is useful for requesting event data because the requesting station does not know in
advance which points have generated events.
octet 1
2
3
4
5
6
7
••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••
•
•
• Object gv
•
Qualifier •
Range
•
• AC • FC = 1 • g = n
v = x • 0000 | 0000 • Start
Stop •
•
•
•
|
•
0
0 •
7
|
9 •
••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••
•
•
•
•
Read object group n variation x.
The qualifier code specifies a range field with a 1 octet start and stop sub-field.
The range field specifies 3 objects starting at index 7 to index 9 inclusive.
The index size has no meaning and is set to 0.
DNP V3.00 Application Layer (Version 0.03)
4-3
• The Outstation may respond within the range specified. This method is useful for
requesting specific data that is known to be valid at the time of the request.
octet 1
2
3
4
5
6
7
8
9
••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••
•
•
• object gv
• Qualifier •
Range
•
•
• AC • FC = 1 • g = n
v = x • 0000 0001 •
Start
•
Stop
•
•
•
•
|
•
0
1
•
700
•
702
•
••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••
•
•
•
•
•
Read object group n, variation x.
The qualifier code specifies a range field with a 2 octet start and stop sub-field.
The range field specifies 3 objects starting at index 700 to index 702 inclusive.
The index size has no meaning and is set to 0.
The Outstation may respond within the range specified. This method is useful for
requesting specific data that is known to be valid at the time of the request.
octet 1
2
3
4
5
6
7
8
9
10
11
12
13
••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••
•
•
•
•
•
•
•
•
• Object gv
• Qualifier •
|
|
| Range |
|
|
•
• AC • FC = 1 • g = n
v = x • 0000 0010 •
Start
•
Stop
•
•
•
•
|
•
0
2
•
70000
•
70002
•
••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••
•
•
•
•
•
Read object group n, variation x.
The qualifier code specifies a range field with a 4 octet start and stop sub-field.
The range field specifies 3 objects starting at index 70000 to index 70002 inclusive.
The Index Size field has no meaning and is set to 0.
The Outstation may respond within the range specified. This method is useful for
requesting specific data that is known to be valid at the time of the request.
octet 1
2
3
4
5
6
7
••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••
•
•
• Object gv
• Qualifier •
Range
•
• AC • FC = 1 • g = n
v = x • 0000 0011 • Start • Stop
•
•
•
•
|
•
0
3
•
7
•
9
•
••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••
• Read object group n, variation x. In this case n and x would specify a generic octet
object
• The qualifier code specifies a range field with a 1 octet start and stop sub-field.
• The range field specifies a starting virtual address of 7 and a virtual ending address of
9.
• The Index Size field has no meaning and is set to 0.
• The Outstation may respond within the range specified. This method is useful for
requesting specific bytes from the memory of some remote application.
NOTE:
4-4
Virtual addressing is normally used only for diagnostic or manufacturing
tests as intimate knowledge of the Outstation is needed to interpret the
response.
DNP Users Group
octet 1
2
3
4
5
6
7
8
9
••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••
•
•
• Object gv
• Qualifier •
|
Range
|
•
• AC • FC = 1 • g = n
v = x • 0000 0100 •
Start
•
Stop
•
•
•
•
|
•
0
4
•
700
•
702
•
••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••
• Read object group n, variation x. In this case n and x would specify a generic octet
object.
• The qualifier code specifies a range field with a 2 octet start and stop sub-field.
• The range field specifies a starting virtual address of 700 and a virtual ending address
of 702.
• The Index Size field has no meaning and is set to 0.
• The Outstation may respond within the range specified. This method is useful for
requesting specific bytes from the memory of some remote application.
NOTE:
Virtual addressing is normally used only for diagnostic or manufacturing
tests as intimate knowledge of the Outstation is needed to interpret the
response.
octet 1
2
3
4
5
6
7
8
9
10
11
12
13
•••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••
•
•
• Object gv
• Qualifier •
|
|
| Range |
|
|
•
• AC • FC = 1 • g = n
v = x • 0000 0101 •
Start
•
Stop
•
•
•
•
|
•
0
5
•
70000
•
70002
•
•••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••
• Read object group n, variation x. In this case n and x would specify a generic octet
object.
• The qualifier code specifies a range field with a 4 octet start and stop sub-field.
• The range field specifies a starting virtual address of 70000 and a virtual ending
address of 70002.
• The index size has no meaning and is set to 0.
• The Outstation may respond within the range specified. This method is useful for
requesting specific bytes from the memory of some remote application.
NOTE:
Virtual addressing is normally used only for diagnostic or manufacturing
tests as intimate knowledge of the Outstation is needed to interpret the
response.
octet 1
2
3
4
5
6
••••••••••••••••••••••••••••••••••••••••••••••••••••••••••
•
•
• Object gv
• Qualifier • Range
•
• AC • FC = 1 • g = n
v = p • 0000 0111 • Quantity •
•
•
•
|
•
0
7
•
3
•
••••••••••••••••••••••••••••••••••••••••••••••••••••••••••
•
•
•
•
Read object group n variation p.
The qualifier code specifies a 1 octet quantity.
The range field specifies 3 objects.
The index size has no meaning and is set to 0.
DNP V3.00 Application Layer (Version 0.03)
4-5
• This method is useful for requesting a limited amount of data of a particular variation
(e.g. analog change events) as the receiving station may not be able to handle the entire
data base of the Outstation.
octet 1
2
3
4
5
6
7
•••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••
•
•
• Object gv
• Qualifier •
Range
•
• AC • FC = 1 • g = n
v = p • 0000 1000 •
Quantity
•
•
•
•
|
•
0
8
•
400
•
•••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••
•
•
•
•
•
Read object group n variation p.
The qualifier code specifies a 2 octet quantity.
The range field specifies 400 objects.
The index size has no meaning and is set to 0.
This method is useful for requesting a limited amount of data of a particular variation
(e.g. binary input with time objects) as the receiving station may not be able to handle
the entire data base (i.e. analog) of the Outstation.
octet 1
2
3
4
5
6
7
8
9
•••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••
•
•
• Object gv
• Qualifier •
Range
•
• AC • FC = 1 • g = n
v = p • 0000 1001 •
Quantity
•
•
•
•
|
•
0
9
•
|
70000
|
•
•••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••
•
•
•
•
•
Read object group n variation p.
The qualifier code specifies a 4 octet quantity.
The range field specifies 70000 objects.
The index size has no meaning and is set to 0.
This method is useful for requesting a limited amount of data of a particular variation
as the receiving station may not be able to handle the entire data base (i.e. analog) of
the Outstation.
octet 1
2
3
4
5
6
7
8
9
••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••
•
•
• Object gv
• Qualifier • Range
•
Indices
•
• AC • FC = 1 • g = n
v = x • 0001 0111 • Quantity •
11
•
22
• 108
•
•
•
•
•
1
7 •
3
•
•
•
•
••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••
•
•
•
•
•
Read object group n, variation x.
The qualifier code specifies a list of objects in the index field.
The range field specifies that the list contains 3 entries.
The index size specifies each entry in the list is a 1 octet index.
This method is useful for requesting some specific points from the remote device. For
example, some critical status points may be requested for analysis or reporting
purposes.
4-6
DNP Users Group
NOTE:
The range field is always the same size as an entry in the index list. This
format would normally be used when the indices have values between 0
and 255.
octet 1
2
3
4
5
6
7
8
9
10
11
12
13
•••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••
•
•
• Object gv
• Qualifier •
Range
•
Indices
•
• AC • FC = 1 • g = n
v = x • 0010 0111 •
Quantity
•
311
•
422
•
108
•
•
•
•
|
•
2
7 •
3
•
|
•
|
•
|
•
•••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••
•
•
•
•
•
Read object group n, variation x.
The qualifier code specifies a list of objects in the index field.
The range field specifies the list contains 3 entries.
The index size specifies each entry in the list is a 2 octet index.
This method is useful for requesting some specific points from the remote device. For
example, some critical status points may be requested for analysis or reporting
purposes.
NOTE:
The range field is always the same size as an entry in the index list. This
format would normally be used when some or all of the indices have
values greater than what will fit in 1 octet.
octet 1
2
3
4
5
6 7 8 9
18 19 20 21
•••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••
•
•
• Object gv
• Qualifier •
Range
•
Indices
•
• AC • FC = 1 • g = n
v = x • 0011 0111 • Quantity •
•
•
•
•
•
•
|
• 3
7
•
3
•
70000
•
76000
•
90000
•
•••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••
•
•
•
•
•
Read object group n, variation x.
The qualifier code specifies a list of objects in the index field.
The range field specifies the list contains 3 entries.
The index size specifies each entry in the list is a 4 octet index.
This method is useful for requesting some specific points from the remote device. For
example, some critical status points may be requested for analysis or reporting
purposes.
NOTE:
The range field is always the same size as an entry in the index list.
octet 1
2
3
4
5
6
7 .....
••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••
•
•
• Object gv
• Qualifier •
Range •
Identifier
•
• AC • FC = 1 • g = n
v = v • 0001 1011 • Quantity •
•
•
•
•
|
•
1
11 •
1
• Size | Object Identifier •
••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••
•
Size octets
•
• Read object group n variation v (in this case the group and variation identify the
object identifier).
DNP V3.00 Application Layer (Version 0.03)
4-7
• The qualifier code specifies a list of object identifiers in the identifier field and the
range field is an 8 bit quantity. The size field is also an 8-bit quantity specifying that
the object identifier is 'size' octets in length.
• The range field specifies the list contains 1 entry. The index size specifies that the
quantity field and Size field are 8-bit in length.
• This method is useful for reading configurations from a remote device (if the File
Object Identifier is used). This method is however the only way in which to request a
data object that is larger than one fragment in size.
4.2.2 Read Responses
This section defines some of the legal forms of an object header prefixing the objects in a
response to a read request.
octet 1
2
3
4
5
•••••••••••••••••••••••••••••••••••••••••••••••••••
• Object gv
• Qualifier •
Range
•
• group = n
• 0000 0000 • Start
• Stop
•
• variation = v •
0
0
•
7
•
9
•
•••••••••••••••••••••••••••••••••••••••••••••••••••
....
.....
• Objects following this header are group n, variation v.
• The qualifier code specifies a range field with a 1 octet start and stop sub-fields.
• The range field specifies 3 objects starting at index 7 to index 9 inclusive follow this
header
• The index size has no meaning and is set to 0 as the start and stop field identify the
index of each object.
octet 1
2
3
4
5
6
7
•••••••••••••••••••••••••••••••••••••••••••••••••••••....
• Object gv
• Qualifier •
Range
•
• group = n
• 0000 0001 • Start
•
Stop
•
• variation = v •
0
1
•
300
•
302
•
•••••••••••••••••••••••••••••••••••••••••••••••••••••....
• Objects following this header are group n, variation v.
• The qualifier code specifies a range field with 2 octet start and stop sub-fields.
• The range field specifies 3 objects starting at index 300 to index 302 inclusive follow
this header.
• The index size has no meaning and is set to 0 as the start and stop field identify the
index of each object.
octet 1
2
3
4 5 6 7
8 9 10 11
•••••••••••••••••••••••••••••••••••••••••••••••••••••••••••....
• Object gv
• Qualifier •
Range
•
• group = n
• 0000 0010 •
Start
•
Stop
•
• variation = v •
0
2
•
70000
•
70002
•
•••••••••••••••••••••••••••••••••••••••••••••••••••••••••••....
• Objects following this header are group n, variation v.
• The qualifier code specifies a range field with 4 octet start and stop sub-fields.
4-8
DNP Users Group
• The range field specifies 3 objects starting at index 70000 to index 70002 inclusive
follow this header.
• The index size has no meaning and is set to 0 as the start and stop field identify the
index of each object.
octet 1
2
3
4
5
••••••••••••••••••••••••••••••••••••••••••••••••••• .....
• Object gv
• Qualifier •
Range
•
• group = n
• 0000 0011 • Start
• Stop
•
• variation = v •
0
3
•
7
•
9
•
••••••••••••••••••••••••••••••••••••••••••••••••••• .....
• Objects following this header are group n, variation v.
• The qualifier code specifies a range field with a 1 octet start and stop sub-fields.
• The range field specifies the contents of virtual addresses 7 to 9 inclusive following
this header.
• The index size has no meaning and is set to 0 as the start and stop field identify the
index of each object.
octet 1
2
3
4
5
6
7
•••••••••••••••••••••••••••••••••••••••••••••••••••••....
• Object gv
• Qualifier •
Range
•
• group = n
• 0000 0100 • Start
•
Stop
•
• variation = v •
0
4
•
300
•
302
•
•••••••••••••••••••••••••••••••••••••••••••••••••••••....
• Objects following this header are group n, variation v.
• The qualifier code specifies a range field with 2 octet start and stop sub-fields.
• The range field specifies the contents of virtual addresses 300 to 302 inclusive
following this header.
• The index size has no meaning and is set to 0 as the start and stop field identify the
index of each object.
octet 1
2
3
4 5 6 7
8 9 10 11
•••••••••••••••••••••••••••••••••••••••••••••••••••••••••••....
• Object gv
• Qualifier •
Range
•
• group = n
• 0000 0101 •
Start
•
Stop
•
• variation = v •
0
5
•
70000
•
70002
•
•••••••••••••••••••••••••••••••••••••••••••••••••••••••••••....
• Objects following this header are group n, variation v.
• The qualifier code specifies a range field with 4 octet start and stop sub-fields.
• The range field specifies the contents of virtual addresses 70000 to 70002 inclusive
following this header.
• The index size has no meaning and is set to 0 as the start and stop field identify the
index of each object.
DNP V3.00 Application Layer (Version 0.03)
4-9
octet 1
2
3
4
••••••••••••••••••••••••••••••••••••••••....
• Object gv
• Qualifier • Range •
• group = n
• 0000 0111 •
3
•
• variation = v •
0
7
•
•
••••••••••••••••••••••••••••••••••••••••....
•
•
•
•
Objects following this header are group n, variation v.
The qualifier code specifies a range field with a 1 octet quantity.
The range field specifies 3 objects.
The index size specifies the objects are packed with no indices prefixing them. This
implies the first object in the message has an index of 0 and the last object in this
example will have an index of 2.
octet 1
2
3
4
••••••••••••••••••••••••••••••••••••••••....
• Object gv
• Qualifier • Range •
• group = n
• 0001 0111 •
3
•
• variation = v •
1
7
•
•
••••••••••••••••••••••••••••••••••••••••....
•
•
•
•
Objects following this header are group n, variation v.
The qualifier code specifies a range field with a 1 octet quantity.
The range field specifies 3 objects.
The index size specifies the objects are prefixed with 1 octet index identifiers.
octet 1
2
3
4
••••••••••••••••••••••••••••••••••••••••....
• Object gv
• Qualifier • Range •
• group = n
• 0010 0111 •
3
•
• variation = v •
2
7
•
•
••••••••••••••••••••••••••••••••••••••••....
•
•
•
•
Objects following this header are group n, variation v.
The qualifier code specifies a range field with a 1 octet quantity.
The range field specifies 3 objects.
The index size specifies the objects are prefixed with 2 octet index identifiers.
octet 1
2
3
4
••••••••••••••••••••••••••••••••••••••••....
• Object gv
• Qualifier • Range •
• group = n
• 0011 0111 •
3
•
• variation = v •
3
7
•
•
••••••••••••••••••••••••••••••••••••••••....
•
•
•
•
Objects following this header are group n, variation v.
The qualifier code specifies a range field with a 1 octet quantity.
The range field specifies 3 objects.
The index size specifies the objects are prefixed with 4 octet index identifiers.
4-10
DNP Users Group
octet 1
2
3
4
•••••••••••••••••••••••••••••••••••••••••••••••....
• Object gv
• Qualifier •
Range
•
• group = n
• 0100 0111 •
Quantity
•
• variation = v •
4
7
•
1
•
•••••••••••••••••••••••••••••••••••••••••••••••....
•
•
•
•
•
Objects following this header are group n, variation v.
The qualifier code specifies the range field is an 8 bit quantity.
The range field specifies the number of the objects in the data field.
The index size specifies the objects are prefixed with 1 octet object sizes.
Note that since the object indices are not specified (and the response and request do
not have to match), the data object itself must contain some unique identification (such
as a time-stamp).
octet 1
2
3
4
5
••••••••••••••••••••••••••••••••••••••••....
• Object gv
• Qualifier • Range •
• group = n
• 0000 1000 •
3
•
• variation = v •
0
8
•
•
••••••••••••••••••••••••••••••••••••••••....
•
•
•
•
Objects following this header are group n, variation v.
The qualifier code specifies a range field with a 2 octet quantity.
The range field specifies 3 objects.
The index size specifies the objects are packed with no indices prefixing them. This
implies the first object in the message has an index of 0 and the last object in this
example will have an index of 2.
• Note that since the object indices are not specified (and the response and request do
not have to match), the data object itself must contain some unique identification (such
as a time-stamp).
octet 1
2
3
4
5
••••••••••••••••••••••••••••••••••••••••....
• Object gv
• Qualifier • Range •
• group = n
• 0001 1000 •
3
•
• variation = v •
1
8
•
•
••••••••••••••••••••••••••••••••••••••••....
•
•
•
•
Objects following this header are group n, variation v.
The qualifier code specifies a range field with a 2 octet quantity.
The range field specifies 3 objects.
The index size specifies the objects are prefixed with a 1 octet index identifier.
octet 1
2
3
4
5
••••••••••••••••••••••••••••••••••••••••....
• Object gv
• Qualifier • Range •
• group = n
• 0010 1000 •
300 •
• variation = v •
2
8 •
•
••••••••••••••••••••••••••••••••••••••••....
• Objects following this header are group n, variation v.
• The qualifier code specifies a range field with a 2 octet quantity.
• The range field specifies 300 objects.
DNP V3.00 Application Layer (Version 0.03)
4-11
• The index size specifies the objects are prefixed with a 2 octet index identifier.
octet 1
2
3
4
5
••••••••••••••••••••••••••••••••••••••••....
• Object gv
• Qualifier • Range •
• group = n
• 0011 1000 •
300 •
• variation = v •
3
8 •
•
••••••••••••••••••••••••••••••••••••••••....
•
•
•
•
Objects following this header are group n, variation v.
The qualifier code specifies a range field with a 2 octet quantity.
The range field specifies 300 objects.
The index size specifies the objects are prefixed with a 4 octet index identifier.
octet 1
2
3
4
5
•••••••••••••••••••••••••••••••••••••••••••••••....
• Object gv
• Qualifier •
Range
•
• group = n
• 0101 1000 •
Quantity
•
• variation = v •
5
8
•
•
•••••••••••••••••••••••••••••••••••••••••••••••....
•
•
•
•
•
Objects following this header are group n, variation v.
The qualifier code specifies the range field is a 16 bit quantity.
The range field specifies the number of objects in the data field.
The index size specifies the objects are prefixed with 2 octet object sizes.
Note that since the object indices are not specified (and the response and request do
not have to match), the data object itself must contain some unique identification (such
as a time-stamp).
octet 1
2
3
4 5 6 7
••••••••••••••••••••••••••••••••••••••••....
• Object gv
• Qualifier • Range •
• group = n
• 0000 1001 •
3
•
• variation = v •
0
9 •
•
••••••••••••••••••••••••••••••••••••••••....
•
•
•
•
Objects following this header are group n, variation v.
The qualifier code specifies a range field with a 4 octet quantity.
The range field specifies 3 objects.
The index size specifies the objects are packed with no indices prefixing them. This
implies the first object in the message has an index of 0 and the last object in this
example will have an index of 2.
octet 1
2
3
4 5 6 7
••••••••••••••••••••••••••••••••••••••••....
• Object gv
• Qualifier • Range •
• group = n
• 0001 1001 •
3
•
• variation = v •
1
9 •
•
••••••••••••••••••••••••••••••••••••••••....
• Objects following this header are group n, variation v.
• The qualifier code specifies a range field with a 4 octet quantity.
• The range field specifies 3 objects.
4-12
DNP Users Group
• The index size specifies the objects are prefixed with a 1 octet index identifier.
octet 1
2
3
4 5 6 7
••••••••••••••••••••••••••••••••••••••••....
• Object gv
• Qualifier • Range •
• group = n
• 0010 1001 •
3
•
• variation = v •
2
9 •
•
••••••••••••••••••••••••••••••••••••••••....
•
•
•
•
Objects following this header are group n, variation v.
The qualifier code specifies a range field with a 4 octet quantity.
The range field specifies 3 objects.
The index size specifies the objects are prefixed with 2 octet index identifiers.
octet 1
2
3
4 5 6 7
••••••••••••••••••••••••••••••••••••••••....
• Object gv
• Qualifier • Range •
• group = n
• 0010 1001 •
3
•
• variation = v •
3
9 •
•
••••••••••••••••••••••••••••••••••••••••....
•
•
•
•
Objects following this header are group n, variation v.
The qualifier code specifies a range field with a 4 octet quantity.
The range field specifies 3 objects.
The index size specifies the objects are prefixed with 4 octet index identifiers.
octet 1
2
3
4
5
6
7
•••••••••••••••••••••••••••••••••••••••••••••••....
• Object gv
• Qualifier •
Range
•
• group = n
• 0100 1001 •
Quantity
•
• variation = v •
4
9 •
•
•••••••••••••••••••••••••••••••••••••••••••••••....
•
•
•
•
•
Objects following this header are group n, variation v.
The qualifier code specifies the range field is a 32 bit quantity.
The range field specifies the number of the objects in the data field.
The index size specifies the objects are prefixed with 1 octet object sizes.
Note that since the object indices are not specified (and the response and request do
not have to match), the data object itself must contain some unique identification (such
as a time-stamp).
DNP V3.00 Application Layer (Version 0.03)
4-13
The read response can also consist of a multi-fragment message with each object
identifier specifying different portions (pages) of the entire object:
Fragment #1: FC=129, CON=? FIR=1 FIN=0
octet 1
2
3
4
5
6
7 .....
•••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••
• Object gv
• Qualifier •
Range •
Identifier
• Data
•
• g = n
v = v • 0001 1011 • Quantity •
• for
•
•
|
•
1
11 •
1
• Size • Object Identifier for piece 1• piece 1 •
•••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••
Size octets
Fragment #2: FC=129, CON=? FIR=0 FIN=0
octet 1
2
3
4
5
6
7 .....
•••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••
• Object gv
• Qualifier •
Range •
Identifier
• Data
•
• g = n
v = v • 0001 1011 • Quantity •
• for
•
•
|
•
1
11 •
1
• Size • Object Identifier for piece 2• piece 2 •
•••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••
Size octets
Fragment #3: FC=129, CON=? FIR=0 FIN=1
octet 1
2
3
4
5
6
7 .....
•••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••
• Object gv
• Qualifier •
Range •
Identifier
• Data
•
• g = n
v = v • 0001 1011 • Quantity •
• for
•
•
|
•
1
11 •
1
• Size • Object Identifier for piece 3• piece 3 •
•••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••
Size octets
• Read object group n variation v (in this case the group and variation identify the object
identifier).
• The qualifier code specifies a list of object identifiers in the identifier field and the
range field is an 8 bit quantity. The size field is also an 8-bit quantity specifying that
the object identifier plus data following the identifier is 'size' octets in length.
• The range field specifies the list contains 1 entry. The index size specifies that the
quantity field and Size field are 8-bit in length.
• This method is useful for reading configurations from a remote device (if the File
Identifier Object is used). This method is however the only way in which to request a
data object that is larger than one fragment in size.
• Note that each fragment is digestible by the requesting station because each object
identifier specifies a unique portion of the object.
4.3 WRITE (FUNCTION CODE 2)
The write function code is used for moving objects from a master station to an Outstation.
Figure 4-4 illustrates the general format of a message writing single object type or range.
Figure 4-5 illustrates the writing of multiple objects or ranges. The object header is
defined the same as in a read request. Figure 4-6 is an example of the writing of a
configuration to an Outstation. The response from the Outstation is always a function
code followed by the IIN. Typical uses of the Write function are to download
configuration or files to an Outstation and to set the time in the Outstation.
4-14
DNP Users Group
••••••••••••••••••••••••••••••••• ...........
•
•
• Object Header •
• AC • FC = 2 •
•
Object(s) and prefixing indices or identifiers
•
•
•
•
••••••••••••••••••••••••••••••••• ...........
Figure 4-4 Single Object Range Write
•••••••••••••••••••••••••••••••••...........••••••••••••••••• ........
•
•
• Object Header •
• Object Header •
• AC • FC = 2 •
• Object(s) •
• Objects(s)
•
•
•
•
•
•
•••••••••••••••••••••••••••••••••......... •••••••••••••••••.........
Figure 4-5 Multiple Object or Multiple Ranges
4.3.1 Write Requests
The Write request transfers a multi-fragment object to a remote device. The Write
Request is typically used for writing objects such as the Internal Indication Object, File
Identifier Objects and the Time and Date Object.
Each fragment contains identifying information for each portion of the entire object.
octet 1
2
3
4
5
6
7 .....
•••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••
• AC
•
• Object gv
• Qualifier •
Range •
Identifier
• Data
•
• FIN=0• FC = 2 • g = n
v = v • 0001 1011 • Quantity •
• for
•
• FIR=1•
•
|
•
1
11 •
1
• Size • Object Identifier for piece 1• piece 1 •
•••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••
Size octets
octet 1
2
3
4
5
6
7 .....
•••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••
• AC
•
• Object gv
• Qualifier •
Range •
Identifier
• Data
•
• FIN=0• FC = 2 • g = n
v = v • 0001 1011 • Quantity •
• for
•
• FIR=0•
•
|
•
1
11 •
1
• Size • Object Identifier for piece 2• piece 2 •
•••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••
Size octets
octet 1
2
3
4
5
6
7 .....
•••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••
• AC
•
• Object gv
• Qualifier •
Range •
Identifier
• Data
•
• FIN=1• FC = 2 • g = n
v = v • 0001 1011 • Quantity •
• for
•
• FIR=0•
•
|
•
1
11 •
1
• Size • Object Identifier for piece 3• piece 3 •
•••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••
Size octets
• Write object group n variation v (in this case the group and variation identify the
object identifier).
• The qualifier code specifies a list of object identifiers in the identifier field and the
range field is an 8 bit quantity. The size field is also an 8-bit quantity specifying that
the object identifier plus data is 'size' octets in length
• The range field specifies the list contains 1 entry.
• The Data field contains the data (of size specified in the identifier) belonging to the
identified object.
• This method is useful for downloading configurations to a remote device (if the File
Object Identifier is used) as the contents of the Data filed is not interpreted by the
DNP V3.00 Application Layer (Version 0.03)
4-15
application layer. This method is however the only way in which to send a data object
that is larger than one fragment in size.
The Write request below sets the time of day in the Outstation.
octet 1
2
3
4
5
6
7 .....
•••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••
• AC
•
• Object gv
• Qualifier •
Range • Time Object •
• FIN=1• FC = 2 • g = n
v = v • 0000 0000 • Quantity •
•
• FIR=1•
•
|
•
0
00 •
1
•
•
•••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••
• The qualifier specifies a 1 octet quantity; the quantity field specifies 1 object and the
Object field identifies the object as a Time and Date Object.
4.3.2 Write Responses
The response to a Write request can only consist of the IIN (Internal Indications) that
indicates the success of the Write operation and so there is no ASDU portion of a Write
response. The response always uses the Response function code.
4.4 SELECT (FUNCTION CODE 3)
The select function code is used to select one or more control points at an Outstation.
These may be control relay outputs, analog outputs or pattern control blocks. This
function does not output or activate the new state or value but makes them ready (arms
them) and reports their status. An additional operate message must be sent to the
Outstation to actually activate the request. The operate message control objects must
match the control objects in the preceding select message before the activation takes
place. The select message causes the Outstation to starts a timer. The operate message
must be received correctly before the timer expires in order for the activation to take
place.
There are two forms to the control messages. The first form is for control blocks with a
fixed size and the second form is for a control block of variable size. The variable sized
control block is for pattern outputs.
Figure 4-6 illustrates a select message (fixed size control blocks) sent from a master
station to an Outstation.
The Outstation responds to a select message by arming the specified points (specified by
the index preceding the control blocks) and returning the request in the response as
illustrated in Figure 4-7 (fixed size control blocks). The response is identical to the
request except that it includes the IIN and modified status bytes (part of the control block
objects). The status bytes state the success or failure of the Select request.
4-16
DNP Users Group
•••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••
•
•
• Object gv
• Qualifier • Range
•
• control •
• control •
• AC • FC = 3 • group = n
• 0001 0111 • Quantity • index • block
• index • block
•
•
•
• variation = v •
1
7 •
2
•
• object 1•
• object 2•
•••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••
Figure 4-6 Master Selection of Two Control or Analog Outputs
• Object following this header is group n (must be a control block object relating to
outputs or setpoints), variation v.
• The qualifier code specifies a range field with a 1 octet quantity of control blocks.
• The index size specifies 1 octet indices prefixing each control block.
•••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••
•
•
•
• Object gv
• Qualifier • Range
•
• control •
• control •
• AC • FC • IIN • group = n
• 0001 0111 • Quantity • index • block
• index • block
•
•
•
•
• variation = v •
1
7 •
•
• object 1•
• object 2•
•••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••
Figure 4-7 Outstation Response
The Outstation response control objects must match the control objects (byte for byte) in
the request or the operate message will not be sent.
4.4.1 Pattern Control
Figure 4-8 illustrates a master station select message for a pattern and
Figure 4-9 an Outstation response.
••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••
•
•
• Object gv
• Qualifier •Quantity• pattern •
• AC • FC = 3 • group = a
• 0000 0111 •
• control •
•
•
• variation = b •
0
7
•
1
• block
•... (continued)
••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••
•••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••
• Object gv
• Qualifier •
Range
•pattern •pattern •pattern •pattern •
• group = c
•0000 0000 • Start | Stop • mask
• mask • mask • mask •
• variation = d • 0
0
•
5
8
•object 5•object 6•object 7•object 8•
•••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••
Figure 4-8 Master Selection of a Pattern Output
• The first object, Object a, Variation b, specified is a Pattern Control Block which
describes all the parameters that are common to the control points specified in the
Pattern Mask Objects. Following this object are a number of Pattern Mask objects,
Object c, Variation d, which describe whether or not the point should be activated.
• The first qualifier code specifies a 8-bit range (quantity) field which specifies one (1)
Pattern Control Block.
• The second qualifier code specifies a range field with a 1 octet start and stop sub-field.
This range specifies the Pattern Mask Objects which are to be considered for the
pattern control.
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• The above message constitutes one pattern control request. Multiple requests (Pattern
Control Block followed by multiple Pattern Mask Objects) can be sent in one message
as long as the total size of the requests can fit into one application layer fragment.
••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••
•
•
• Object gv
• Qualifier •Quantity• pattern •
• AC • FC=128 • group = a
• 0000 0111 •
• control •
•
•
• variation = b •
0
7
•
1
• block
•... (continued)
••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••
•••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••
• Object gv
• Qualifier •
Range
•pattern •pattern •pattern •pattern •
• group = c
•0000 0000 • Start | Stop • mask
• mask • mask • mask •
• variation = d • 0
0
•
5
8
•object 5•object 6•object 7•object 8•
•••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••
Figure 4-9 Outstation Response to the Pattern Select Message
• Notice that the format of the response is identical to the request message (except the
application response header). The objects returned will be used by the master to verify
the success of the select operation.
4.5 OPERATE (FUNCTION CODE 4)
The operate function code is used to activate one or more control or analog outputs at an
Outstation. A matching message using the select function code must previously have
been received, and the arm timer must still be active before the activation will take place.
The format of this message is the same as a select message except the function code is 4.
•••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••
•
•
• Object gv
• Qualifier •
Range
• control • control
•
• AC • FC = 4 • group = n
• 0000 0111 •
Quantity • block 1 • block 2
•
•
•
• variation = v •
0
7
•
2
•
•
•
•••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••
Figure 4-10 Master Selection of Two Outputs or Setpoints
• Object following this header is group n (must be a control block object relating to
outputs or setpoints), variation v.
• The qualifier code specifies a range field with a 1 octet quantity of control blocks.
••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••
•
•
•
• Object gv
• Qualifier • Range
• control • control •
• AC • FC • IIN • group = n
• 0000 0111 • Quantity • block 1 • block 2 •
•
•
•
• variation = v •
0
7
•
2
•
•
•
••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••
Figure 4-11 Outstation Response
• Object following this header is group n (must be a control block object relating to
outputs or setpoints), variation v.
• The qualifier code specifies a range field with a 1 octet quantity of control blocks.
• Indication of the success or failure of the operations is returned in the Output Status
bytes, one of which is built into each of the control block objects. In the case of a
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DNP Users Group
Pattern Mask object, the status is part of the Pattern Control Block object preceding
the mask.
4.6 DIRECT OPERATE (FUNCTION CODE 5)
The direct operate function code is used to activate one or more outputs or setpoints at an
Outstation. A preceding select message is not required. The format of this message is the
same as a select or operate message except the function code is 5.
•••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••
•
•
• Object gv
• Qualifier •
Range
• control • control
•
• AC • FC = 5 • group = n
• 0000 0111 •
Quantity • block 1 • block 2
•
•
•
• variation = v •
0
7 •
2
•
•
•
•••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••
Figure 4-12 Master Selection of Two Outputs or Setpoints
• Object following this header is group n (must be a control block object relating to
outputs or setpoints), variation v.
• The qualifier code specifies a range field with a 1 octet quantity of control blocks.
•••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••
•
•
•
• Object gv
• Qualifier • Range
• control • control •
• AC • FC • IIN • group = n
• 0000 0111 • Quantity • block 1 • block 2 •
•
•
•
• variation = v •
0
7
•
2
•
•
•
•••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••
Figure 4-13 Outstation Response
• Object following this header is group n (must be a control block object relating to
outputs or setpoints), variation v.
• The qualifier code specifies a range field with a 1 octet quantity of control blocks.
4.7 DIRECT OPERATE - NO ACKNOWLEDGEMENT (FUNCTION
CODE 6)
The direct operate No Acknowledgement function code is used to activate one or more
outputs or setpoints at a Outstation. A preceding select message is not required. The
format of this message is the same as a select or operate message except the function code
is 6 and the Outstation does not respond with a message to the master station.
•••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••
•
•
• Object gv
• Qualifier •
Range
• control • control
•
• AC • FC = 6 • group = n
• 0000 0111 •
Quantity • block 1 • block 2
•
•
•
• variation = v •
0
7
•
2
•
•
•
•••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••
Figure 4-14 Master Selection of Two Outputs or Setpoints
• Object following this header is group n (must be a control block object relating to
outputs or setpoints), variation v.
• The qualifier code specifies a range field with a 1 octet quantity of control blocks.
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4.8 IMMEDIATE FREEZE (FUNCTION CODE 7)
This function code is used to copy the specified data objects to a freeze buffer. Upon
reception of the message, the Outstation should copy the current values of the specified
data objects to their appropriate freeze buffers. The objects which were frozen can be
requested (in another request) by asking for frozen objects.
•••••••••••••••••••••••••••••••
•••••••••••••••••
•
•
• Object Header •
• Object Header •
• AC • FC = 7 •
•...•
•
•
•
•
•
•
•
•••••••••••••••••••••••••••••••
•••••••••••••••••
Figure 4-15 Master Immediate Freeze Control Message
The request can contain multiple object headers which specify many objects to freeze.
Typically, however, only counter objects are frozen.
••••••••••••••••••••••••
•
•
•
•
• AC • FC •
IIN
•
•
•
•
•
••••••••••••••••••••••••
Figure 4-16 Outstation Response to Immediate Freeze
The Outstation response can indicate (in the IIN) that the objects in the request are not
known.
4.9 IMMEDIATE FREEZE - NO ACKNOWLEDGEMENT
(FUNCTION CODE 8)
This function code works identically to the previous function code (Immediate Freeze)
except that no Outstation response is needed. Typically, this function code is used to
perform a global freeze on all Outstations belonging to the master. In this case, the
SEND-NO REPLY services of the Data Link Layer may have to be used in certain
environments.
•••••••••••••••••••••••••••••••
•••••••••••••••••
•
•
• Object Header •
• Object Header •
• AC • FC = 8 •
•...•
•
•
•
•
•
•
•
•••••••••••••••••••••••••••••••
•••••••••••••••••
Figure 4-17 Master Immediate Freeze No-Ack Control Message
4.10 FREEZE AND CLEAR (FUNCTION CODE 9)
This function code is used to copy the specified data to a freeze buffer like the freeze
immediate function code but then the Outstation clears ( to 0 ) the specified data objects.
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DNP Users Group
Typically, this function code is used to freeze counters or accumulators and then reset
them to 0.
•••••••••••••••••••••••••••••••
•••••••••••••••••
•
•
• Object Header •
• Object Header •
• AC • FC = 9 •
•...•
•
•
•
•
•
•
•
•••••••••••••••••••••••••••••••
•••••••••••••••••
Figure 4-18 Master Freeze and Clear Control Message
••••••••••••••••••••••••
•
•
•
•
• AC • FC •
IIN
•
•
•
•
•
••••••••••••••••••••••••
Figure 4-19 Outstation Response to Freeze and Clear Request
4.11 FREEZE AND CLEAR - NO ACKNOWLEDGEMENT
(FUNCTION CODE 10)
This function code works identically to the previous function code (Freeze and Clear)
except that no Outstation response is needed. Typically, this function code is used to
perform a global freeze and clear on all Outstations belonging to the master.
•••••••••••••••••••••••••••••••
•••••••••••••••••
•
•
• Object Header •
• Object Header •
• AC • FC= 10 •
•...•
•
•
•
•
•
•
•
•••••••••••••••••••••••••••••••
•••••••••••••••••
Figure 4-20 Master Freeze and Clear No-Ack Control Message
4.12 FREEZE WITH TIME (FUNCTION CODE 11)
This function code initiates the periodic freezing of the specified data objects. The Time
and Date with Interval object sent preceding the objects to freeze is described in the table
below. As shown, the object has two components: a time field (absolute) and an interval
time field. The value of these fields determines the behaviour of the Outstation freezing.
TIME
non zero
zero
zero
INTERVAL
zero
zero
non zero
non zero
non zero
DESCRIPTION
Freeze once at specified time.
Freeze Immediately.
Freezing is synchronized to the
beginning of the current hour. The first
freeze will occur at the smallest
multiple greater than or equal to the
current time. Subsequent freezes will
occur at each interval increment.
Start freezing at the specified time and
repeat at each interval increment
thereafter
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••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••
•
•
• Object Header
•
Time Object
• Object Header(s) •
• AC • FC = 11 • for time object • Time and Date • Interval • for data objects •
•
•
•
•
•
• to freeze
•
••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••
Figure 4-21 Master Freeze With Time Message
••••••••••••••••••••••••
•
•
•
•
• AC • FC •
IIN
•
•
•
•
•
••••••••••••••••••••••••
Figure 4-22 Outstation Response to Freeze With Time
The time object must contain the time and interval. These objects are defined in the DNP
Data Object Library (P009-0BL).
Example: A time object specifies the time of day as 2:32 pm and an interval of 10
minutes. The first freeze will occur at 2:32 pm and subsequent freezes every 10 minutes
starting from 2:42 pm.
4.13 FREEZE WITH TIME - NO ACKNOWLEDGEMENT
(FUNCTION CODE 12)
This function code works identically to the previous function code (Freeze With Time)
except that no Outstation response is needed. Typically, this function code is used to
perform a global freeze with time on all Outstations belonging to the master. In this case,
the SEND-NO REPLY services of the Data Link Layer may have to be used in certain
environments.
••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••
•
•
• Object Header
•
Time Object
• Object Header(s) •
• AC • FC = 12 • for time object • Time and Date • Interval • for data objects •
•
•
•
•
•
• to freeze
•
••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••
Figure 4-23 Master Freeze With Time No-Ack Message
4.14 COLD RESTART (FUNCTION CODE 13)The cold restart function
code makes the Outstation perform a complete restart of the user application , as if it has
been newly powered up.
•••••••••••••••
•
•
•
• AC • FC = 13•
•
•
•
•••••••••••••••
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DNP Users Group
Figure 4-24 Master Cold Restart Control Message
••••••••••••••••••••••••••••••••••••••••••••••••••••
•
•
•
•
Object • Time Delay
•
• AC • FC •
IIN
•
Header •
Object
•
•
•
•
• for time •
•
••••••••••••••••••••••••••••••••••••••••••••••••••••
Figure 4-25 Outstation Response to Cold Restart Request
The Outstation, upon receiving the Cold Restart request will response with a Time Delay
Object (Time Delay Fine or Time Delay Course) which specifies a time interval until the
Outstation will be ready for further communications. The master should not attempt to
communicate with the Outstation until the interval has elapsed. The interval allows the
Outstation to perform a restart sequence and enable DNP communications again. After
the response is sent (and transaction was successful) the Outstation should perform the
restart procedure. The Time Delay Fine object is defined in the DNP Data Object Library
(P009-0BL).
4.15 WARM RESTART (FUNCTION CODE 14)
This code restart function code specifies that the Outstation perform a restart, but it is not
necessary to run through the entire reset sequence (only certain applications need be
restarted). The DNP application may reset itself without resetting other subsystems or
processes. Typically this function makes an Outstation application initialize its
configuration and clear events stored in its local buffers.
••••••••••••••••
•
•
•
• AC • FC = 14 •
•
•
•
••••••••••••••••
Figure 4-26 Master Warm Restart Control Message
•••••••••••••••••••••••••••••••••••••••••••••••••••
•
•
•
•
Object • Time Delay •
• AC • FC •
IIN
•
Header •
Object
•
•
•
•
• for time •
•
•••••••••••••••••••••••••••••••••••••••••••••••••••
Figure 4-27 Outstation Response to Warm Restart Request
The Outstation response is identical to the response to the Cold Restart function code and
should be interpreted in the same way. The Time Delay Object is actually a Time Delay
Fine or Time Delay Course object.
4.16 INITIALIZE DATA (FUNCTION CODE 15)
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4-23
This function code specifies that configurable data is to be set to the initial or default
settings. For example, this function could be used to clear counters. Note that the initial
settings are NOT contained in the request.
•••••••••••••••••••••••••••••••••••
•
•
• Object Header
•
• AC • FC = 15 • for data objects •
•
•
• to initialize
•
•••••••••••••••••••••••••••••••••••
Figure 4-28 Master Initialize Data Control Message
••••••••••••••••••••••••
•
•
•
•
• AC • FC •
IIN
•
•
•
•
•
••••••••••••••••••••••••
Figure 4-29 Outstation Response to Initialize Data Request
The response only indicates the success or failure of the requested operation.
4.17 INITIALIZE APPLICATION (FUNCTION CODE 16)
This function code initializes the specified applications at the Outstation in preparation
for execution.
octet 1
2
3 4
5
6
7...
••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••
•
•
• Object gv
• Qualifier •
Range
• Application •Application •
• AC • FC = 16 • Group = n
• 0001 1011 •
Quantity • Identifier •Object
•
•
•
• Variation = v •
1
11 •
1
• Size
•Identifier
•
••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••
Figure 4-30 Master Initialize Application Control Message
• The object group and variation must specify an application identifier object.
• The qualifier indicates the range field is an 8 bit quantity specifying the number of
object identifiers that follow.
• The application identifier size field indicates the size of the Application Object
Identifier that follows.
••••••••••••••••••••••••
•
•
•
•
• AC • FC •
IIN
•
•
•
•
•
••••••••••••••••••••••••
Figure 4-31 Outstation Response After Initializing Application(s)
The Outstation, upon receiving the request, should initialize the specified application(s)
and then respond with either the success or failure of the transaction.
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DNP Users Group
4.18 START APPLICATION (FUNCTION CODE 17)
This function code is used to start the specified application(s) at the Outstation.
octet 1
2
3 4
5
6
7...
••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••
•
•
• Object gv
• Qualifier •
Range
• Application •Application •
• AC • FC = 17 • Group = n
• 0001 1011 •
Quantity • Identifier •Object
•
•
•
• Variation = v •
1
11 •
1
• Size
•Identifier
•
••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••
Figure 4-32 Master Start Application Control Message
• The object group and variation must specify an application identifier object.
• The qualifier indicates the range field is an 8 bit quantity specifying the number of
object identifiers that follow.
• The application identifier size field indicates the size of the Application Object
Identifier that follows.
•••••••••••••••••••••••••••••••••••••••••••••••••••
•
•
•
•
Object • Time Delay •
• AC • FC •
IIN
•
Header •
Object
•
•
•
•
• for time •
•
•••••••••••••••••••••••••••••••••••••••••••••••••••
Figure 4-33 Outstation Response After Starting Application(s)
The Outstation, upon receiving the request, should start the specified application(s) and
then respond with either the success or failure of the transaction.
4.19 STOP APPLICATION (FUNCTION CODE 18)
This function code informs the Outstation to stop the execution of the specified
application.
octet 1
2
3 4
5
6
7...
••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••
•
•
• Object gv
• Qualifier •
Range
• Application •Application •
• AC • FC = 18 • Group = n
• 0001 1011 •
Quantity • Identifier •Object
•
•
•
• Variation = v •
1
11 •
1
• Size
•Identifier
•
••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••
Figure 4-34 Master Stop Application Control Message
• The object group and variation must specify an application identifier object.
• The qualifier indicates the range field is an 8 bit quantity specifying the number of
object identifiers that follow.
• The application identifier size field indicates the size of the Application Object
Identifier that follows.
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••••••••••••••••••••••••
•
•
•
•
• AC • FC •
IIN
•
•
•
•
•
••••••••••••••••••••••••
Figure 4-35 Outstation Response After Stopping Application(s)
The Outstation, upon receiving the request, should stop the specified application(s) and
then respond with either the success or failure of the transaction.
4.20 SAVE CONFIGURATION (FUNCTION CODE 19)
This function initiates the saving of the specified configuration(s) to nonvolatile storage
at the Outstation station.
octet 1
2
3 4
5
6
7...
•••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••
•
•
• Object gv
• Qualifier •
Range
• File
•File
•
• AC • FC = 19 • Group = n
• 0001 1011 •
Quantity • Identifier
•Identifier
•
•
•
• Variation = v •
1
11 •
1
• Object Size •Object
•
•••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••
Figure 4-36 Master Save Configuration Control Message
• The object group and variation must specify a configuration or file identifier object.
• The qualifier indicates the range field is an 8 bit quantity specifying the number of
object identifiers that follow.
• The configuration identifier size field indicates the size of the configuration Object
Identifier that follows.
•••••••••••••••••••••••••••••••••••••••••••••••••
•
•
•
•
Object
•
Time
•
• AC • FC •
IIN
•
Header
•
Object •
•
•
•
•
•
•
•••••••••••••••••••••••••••••••••••••••••••••••••
Figure 4-37 Outstation Response After Saving Configuration(s)
The Outstation, upon receiving the request, should save the specified configuration(s) and
then respond with either the success or failure of the transaction and a time object (Time
Delay Fine or Time Delay Course) which indicates the time at which the Outstation will
be available again for communication. The master should not attempt to communicate
with the Outstation until the time specified.
4.21 ENABLE SPONTANEOUS MESSAGES (FUNCTION CODE
20)
This function code informs the Outstation to enable spontaneous reporting of the objects
specified in the object header.
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••••••••••••••••••••••••••••••••••
•
•
• Object Header(s) •
• AC • FC= 20 •
•
•
•
•
•
••••••••••••••••••••••••••••••••••
Figure 4-38 Master Request to Enable Spontaneous Messages
••••••••••••••••••••••••
•
•
•
•
• AC • FC •
IIN
•
•
•
•
•
••••••••••••••••••••••••
Figure 4-39 Outstation Response
The Outstation will enable spontaneous messages for all object (types or points) specified
in the object header. The master could also send an object header specifying class data.
This means that any objects which are configured for the specified class will be enabled
for spontaneous messages.
4.22 DISABLE SPONTANEOUS MESSAGES (FUNCTION CODE
21)
This function code informs the Outstation to disable spontaneous reporting of the objects
specified in the object header.
••••••••••••••••••••••••••••••••
•
•
• Object Header •
• AC • FC = 21 •
•
•
•
•
•
••••••••••••••••••••••••••••••••
Figure 4-40 Master Request to Disable Spontaneous Messages
••••••••••••••••••••••••
•
•
•
•
• AC • FC •
IIN
•
•
•
•
•
••••••••••••••••••••••••
Figure 4-41 Outstation Response to Disable Spontaneous Message
The Outstation will disable spontaneous messages for all object (types or points)
specified in the object header. The master could also send an object header specifying
class data. This means that any objects which are configured for the specified class will
be disabled for spontaneous messages.
4.23 ASSIGN CLASSES (FUNCTION CODE 22)
This function is used to assign data objects to classes.
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•••••••••••••••••••••••••••••••••••••••••••••••..•••••••••••••••••
•
•
• Class Object • Data Object • • Data Object •
• AC • FC = 22 •
Header
•
Header 1 • •
Header n
•
•
•
•
•
• •
•
•••••••••••••••••••••••••••••••••••••••••••••••..•••••••••••••••••
Figure 4-42 Master Request to Assign Classes to Data
• The class object header must specify the class object group and a variation between 1
and 3 indicating the class assignment to all the data object (specified by the headers)
that follow.
• The data object header(s) identifies the group, variation and range of the objects to be
assigned to the class specified in the class object header preceding the data object
header.
• Multiple sets of Class Object headers followed by one or more Data Object headers
can be sent in one message. Each set must not span multiple fragments, however.
• Static data objects are assigned to Class 0 and cannot be assigned to other classes.
Event data objects are assigned to classes 1, 2 and/or 3 and cannot be assigned to Class
0.
•••••••••••••••••
•
•
•
•
• AC • FC • IIN •
•
•
•
•
•••••••••••••••••
Figure 4-43 Outstation Response to Assign Classes
The Outstation response indicates the success or response of the operation (success or
failure determined by the state of the IIN bits).
4.24 DELAY MEASUREMENT (FUNCTION CODE 23)
This function is used to calculate the communication delay for a particular Outstation. It
is generally used in the time synchronization process for the Outstations (see section 6.
Time Synchronization for a detailed description of the process).
••••••••••••••••
•
•
•
• AC • FC = 23 •
•
•
•
••••••••••••••••
Figure 4-44 Master Request to Initiate Delay Measurement
• Only one time object can be sent in any one separate request.
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DNP Users Group
•••••••••••••••••••••••••••••••••••••••••••••••
•
•
•
• Time Delay • Time Delay
•
• AC • FC • IIN • Fine Header • Fine object •
•
•
•
•
•
•
•••••••••••••••••••••••••••••••••••••••••••••••
Figure 4-45 Outstation Reponse to Delay Measurement Request
The Outstation responds with the Time Delay Fine object. This object states the number
of milliseconds elapsed between the Outstation receiving the first bit of the first byte of
the request and the time of transmission of the first bit of the first byte of the response.
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DNP Users Group
5. CLASSES
Objects may be assigned to a class. There are four Classes of data. Class 0 is reserved for
static data objects (static data reflects the current value of data in the Outstation). Classes
1, 2 and 3 are reserved for event data objects (objects created as the result of data changes
in the Outstation or some other stimulant). Each event object can be assigned to Class 1,
2 or 3. Objects may be grouped in Classes by priority (the priority is determined by the
user) and the data classes polled at varying rates.
The ability to assign data to Classes and the degree of configurability is described in the
Outstation's device profile. It is not required that an Outstation have data assigned to
Classes 1, 2 or 3.
Class data is used by a master station to request pre-assigned data objects on a demand or
availability basis from an Outstation. Therefore, a class data object header can be used
only in a request (with no associate data object) to indicate to the Outstation which data
objects to return. The Outstation will return (in the response) object headers for the
ACTUAL data objects and NOT the class object header.
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DNP Users Group
6. TIME SYNCHRONIZATION
Time synchronization is handled by the application layer BUT has to make use of special
services of the data link layer. The application must initiate the time synchronization
sequence by sending the appropriate request or response.
To synchronize Master station and Outstation time, the following procedure is used.
1. The Master station sends a Delay Measurement request to the Outstation. The master
records the time of transmission of the first bit of the first byte of the request
(MasterSendTime).
2. The Outstation receives the first bit of the first byte of the Delay Measurement
request at time RtuReceiveTime (this is a local time in the Outstation).
3. The Outstation transmits the first bit of the first byte of the response to the Delay
Measurement request at time RtuSendTime. The response contains the Time Delay
object (Time Delay Fine or Time Delay Course), with the time in this object equal to
RtuTurnAround, where
RtuTurnAround = RtuSendTime - RtuReceiveTime
4. The Master station receives the first bit of the first byte of the Outstation's response at
time MasterReceiveTime.
5. The master station can now calculate the one way propagation delay as
Delay =
MasterSendTime - MasterReceiveTime - RtuTurnAround
---------------------------------------------------2
6. The master now transmits the first bit of the first byte of a Write request at time
MasterSend. The Write request contains the Time and Date object, with the time in
the object representing a time equal to (MasterSend + Delay). This is the time that the
Master station wants the Outstation to be set to.
7. The Outstation receives the first bit of the first byte of the Write request at time
RtuReceive.
DNP V3.00 Application Layer (Version 0.03)
6-1
8. The Outstation will process the Write request, setting the Outstation clock to time
NewRtuTime. The following algorithm is used:
Adjustment = CurrentRtuTime - RtuReceive
NewRtuTime = (time in the Time and Date object) + Adjustment
9. The Master and Outstation time are now synchronized.
NOTE:
The Time Synchronization scheme assumes that the Outstation to master
propagation delay and the master to Outstation propagation delay are
equal.
If desired, the master station may send a global request (using the reserved destination
address of FFFF hexadecimal) to simultaneously synchronize all Outstations, only if all
path delays are equal.
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DNP Users Group
7. BINARY INPUT WITH TIME
EVENTS
An Outstation will often transmit Binary Input with Time or Binary Input with Relative
Time objects when digital input points changes state. Binary input event objects are
transmitted in different formats depending on different conditions.
1) Outstation Time Synchronized, one event object to send. The data is transmitted in
the Binary Input with Time object format.
2) Outstation Time Synchronized, several event object to send. The Time and Date
Common Time of Occurrence object is transmitted followed by several Binary Input
with Relative Time objects. The time in the Time and Date Common Time of
Occurrence object is the time of the oldest object. The relative times start at 0 (for the
oldest object) and range upwards relative to the Date and Time object.
3) Outstation Time NOT Synchronized, one or more event object to send. The
Unsynchronized Common Time and Date object is transmitted followed by one or
more Binary Input with Relative Time objects. The time in the Time and Date
Common Time of Occurrence object is the time of the oldest object. The relative times
start at 0 (for the oldest object) and range upwards relative to the Time and Date
object.
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8. FILE TRANSFER
The File Identifier Object (FIO) may be used to transfer data files between
Outstations and master stations. This is commonly used to write configurations
from a master to an Outstation or read configurations from an Outstation to a
master.
The functionality of the File Identifier Object allows configuration information to
be routed to Outstations via intermediate Data Concentrators. A data
concentrator is located between a master station and an Outstation - it is
effectively an Outstation to the master station and a master station to the
Outstation. Note that a Data Concentrator is not just a communication node - it
does not directly route messages between a master station and an Outstation.
The File Identifier Object is always passed to an Outstation in a request using the
WRITE function code. The action to be done (reading, writing or otherwise) is
specified by the File_Function field within the object. The response always uses
the RESPONSE function code. However, an outstation can send an unsolicited
message containing a FIO.
The File Identifier Object contains routing information in its File_Name field.
This field describes how the object is to be routed from the master station, through
any number of intermediate Data Concentrators, to the Outstation.
The interpretation of the File_Name field is dependent on the Data Concentrator
through which the object is being routed.
8.1 FILE IDENTIFIER OBJECTS PERFORMING WRITE
FUNCTIONS
This section describes how a File Identifier Object is passed from a master station
through a Data Concentrator to an Outstation. The Outstation may be another Data
Concentrator. Note that the request message is using the WRITE function code.
The File_Function field in the object will be WRITE, APPEND, INSERT,
DELETE or ERASE. The object may or may not contain data (no data for
DELETE or ERASE).
DNP V3.00 Application Layer (Version 0.03)
8-1
The following Nomenclature is used:
• Outstation Application - This is the software application in the Data
Concentrator that communicates to the master station. It is an Outstation with
respect to the master station.
• Master Application - This is the software application in the Data Concentrator
that communicates to the Outstation. It is a master with respect to the
Outstation.
The master station send the request (WRITE function code) with the File
Identifier Object to the Outstation Application. For the request, the following
conditions must be satisfied;
• DNP WRITE Function Code is used in the request.
• File_Function field in the object is set to WRITE, APPEND, INSERT,
DELETE or ERASE.
• File_Name field contains an ASCII character string. The length and contents of
the string is dependant on the Data Concentrator. The Harris implementation
uses a string, the first 9 character of which are "/DNPDCAxx", where xx (2
ASCII characters) contains the Master Application number to which this File
Identifier Object must be routed. This information routes the object from the
Outstation Application to the Master Application within the Data Concentrator,
which will send it on to the Outstation.
If the above conditions are met, the following sequence occurs:
Outstation Application sends a CONFIRMation response to the master
1)
station (if the CON bit in the Request Header is set).
Outstation Application removes the first 9 characters (for HARRIS
2)
implementation) from the FILE_NAME field, modifying other File
Identifier Object fields if necessary.
Outstation Application sends the File Identifier Object to the Master
3)
Application.
Master Application sends a request (WRITE function code) containing the
4)
File Identifier Object to the appropriate Outstation.
5)
If a CONFIRMation Response is required, the Master Application waits
for this response.
Master Application now waits for the response containing the File
6)
Identifier Object. The object in the response contains the status of the
command specified in the File_Function field. When this object is
received, the Master Application sends it to the Outstation Application. If
the Master Application does not receive the object, a negative
acknowledgement is sent to the Outstation Application.
7)
Upon receipt of a response File Identifier Object or negative
acknowledgement (from the Master Application), the Outstation
Application sends a response to the master. The transaction is complete.
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DNP Users Group
The response to the request uses the RESPONSE Function Code. It contains the
File Identifier Object, which contains the status of the operation requested in the
File_Function field, with no data records. If the Outstation Application receives a
response from the Master Application, this response contains a File Identifier
Object. The Outstation Application does not need to change this response. If the
Outstation Application receives a negative acknowledgement from the Master
Application, it will modify and set the following fields in the response File
Identifier Object:
START_RECORD = END_RECORD = 0
FILE_SIZE = 0
FILE_FUNCTION = RESPONSE
PERMISSION = 0
Master Application was unable to pass the File Identifier
STATUS = 2
Object to the Master Application.
4
Operation unsuccessful because the device addressed by
FILE_ID is offline.
4
Operation unsuccessful because a negative
acknowledgement received from the Master Application.
The File_Name field is designed so that File Identifier Objects containing
configurations can be downloaded to an Outstation via any number of
intermediate data concentrators.
Figure 8-1 is a simplistic example illustrating how the File Identifier Object is
passed through the system from a master station to an Outstation via two data
concentrators.
DNP V3.00 Application Layer (Version 0.03)
8-3
•
•
↓ FILE_NAME = /DNPDCA03/DNPDCA10/config1
••••••••••••••••••••••••••••••••••
• Outstation application removes•
• 1st 9 chars of FILE_NAME
•
•--------------------------------•
• sends object to internal
• First Data Concentrator
• device number 03
• Outstation Application
•--------------------------------• has Address DST=1
• Master applic. configuration •
• maps device 03 to DST=22
•
• Master applic. addresses
•
• the object to DST=22
•
••••••••••••••••••••••••••••••••••
•
•
↓ FILE_NAME = /DNPDCA10/config1
••••••••••••••••••••••••••••••••••
• Outstation application removes•
• 1st 9 chars of FILE_NAME
•
•--------------------------------•
• sends object to internal
• Second Data Concentrator
• device number 10
• Outstation Application
•--------------------------------• has Address DST=22
• Master applic. configuration •
• maps device 10 to DST=8
•
• Master applic. addresses
•
• the object to DST=8
•
••••••••••••••••••••••••••••••••••
•
•
↓ FILE_NAME = /config1
••••••••••••••••••••
•
•
• End Device
•
• Address 8
•
•
•
••••••••••••••••••••
Figure 8-1 Passing a File Identifier Object Via Data Concentrators
In Figure 8-1:
1)
2)
3)
4)
5)
6)
8-4
The master station WRITEs the File Identifier Object to the first data
concentrator (DC). The File_Name field specifies that the object is to be
sent to device number 3 in the first DC.
The Outstation Application in the first DC removes the first nine
characters of the File_Name. It then routes the object to the Master
Application specified as device number 3.
The Master Application configuration specifies device number 3 has DNP
destination address 22. The Master Application in the first DC WRITEs
the File Identifier Object to the second DC.
The second DC receives the WRITE request. The File_Name field
specifies that the object is to be sent to device number 10 in the second
DC.
The Outstation Application in the second DC removes the first nine
characters of the File_Name. It then routes the object to the Master
Application specified as device number 10.
The Master Application configuration specifies device number 10 has
DNP destination address 8. The Master Application in the second DC
WRITEs the File Identifier Object to the Outstation.
DNP Users Group
7)
8)
9)
10)
11)
The Outstation receives the WRITE request. It responds with a
RESPONSE containing the modified File Identifier Object. This object
contains the status of the operation. It is transmitted to the Master
Application in the second DC.
The Master Application in the second DC transfers the response File
Identifier Object to the Outstation Application.
The Outstation Application sends a RESPONSE containing the File
Identifier Object to the first DC.
The Master Application in the first DC transfers the response File
Identifier Object to the Outstation Application.
The Outstation Application in the first DC sends a RESPONSE containing
the File Identifier Object to the DNP master station.
NOTES:
• This functionality requires the DNP master station to have a larger response
timeout than the Outstation Application in the first DC, which in turn has a
larger response timeout than the Outstation Application in the second DC.
• The DNP master station must have detailed configuration and routing
information in order to construct the File_Name field.
• AN Outstation Application will not receive while it waits for a response from a
down stream device. It is "locked out" to master requests.
8.2 FILE IDENTIFIER OBJECT PERFORMING READ
FUNCTIONS
This section describes how a File Identifier Object is used to perform read
functions. Note that the object is passed to applications via a request using the
WRITE function code. The File_Function field is set to READ.
The master station can read the File Identifier Object when the following
conditions are met:
•
The DNP WRITE Function Code is used in the request.
•
The File_Function field in the File Identifier Object received in the
request is set to READ.
•
The File_Name field contains an ASCII character string. The length and
contents of the string is dependant on the DC. The HARRIS
implementation uses a string, the first 9 character of which are
"/DNPDCAxx", where xx (2 ASCII characters) contains the Master
Application number of the destination for this File Identifier Object. This
information routes the object through the DC to the Master Application
which will send it on from the DC to the Outstation.
If the above conditions are met, the following sequence occurs;
1)
The Outstation Application sends a CONFIRMation response to the DNP
master station (if required).
8-5
DNP V3.00 Application Layer (Version 0.03)
2)
3)
5)
6)
7)
8)
The Outstation Application removes the first 9 characters from the
File_Name field( for HARRIS implementation), modifying the File
Identifier Object as required.
The Outstation Application sends a READ command with the File
Identifier Object to the Master Application.
The Master Application sends a READ command with the File Identifier
Object to the appropriate Outstation.
If a CONFIRMation Response is required, the Master Application waits
for this response.
The Master Application now waits for the response containing the
requested File Identifier Object. When this object is received, the Master
Application sends the response to the Outstation Application. If the Master
Application does not receive the object, a negative acknowledgement is
sent to the Outstation Application.
Upon receipt of an response File Identifier Object or negative
acknowledgement, the Outstation Application sends a response to the
master. The transaction is complete.
Some error conditions can occur in the above sequence. In the cases where the
Outstation Application cannot pass the request to the Master Application or a
negative acknowledgement is received from the Master Application, the
Outstation Application returns the File Identifier Object received as part of the
request to the master station.
The Outstation Application will modify and set the following fields in the
response File Identifier Object;
START_RECORD = END_RECORD = 0
FILE_SIZE = 0
FILE_FUNCTION = RESPONSE
PERMISSION = 0
Outstation Application was unable to pass the File
STATUS = 2
Identifier Object to the Master Application.
4
Operation unsuccessful because the device addressed by
FILE_ID is offline.
4
Operation unsuccessful because a negative
acknowledgement received from the Master Application.
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DNP Users Group
LIST OF ABBREVIATIONS AND
ACRONYMS
AC
APCI
APDU
ASDU
application control
application protocol control information
application protocol data unit
application service data unit
COS
change of state
DA
DC
DNP
DUI
distribution automation
data concentrator
distributed network protocol
data unit identifiers
EPA
enhanced protocol architecture
IEC
IIN
IO
ISO
International Electrotechnical Commission
internal indications
information objects
International Standards Organization
OSI
PDU
Open System Interconnection
protocol data unit
RTU
remote terminal unit
SCADA
SEQ
supervisory control and data acquisition
sequence number
DNP V3.00 Application Layer (Version 0.03)
1
DOCUMENT REVISION HISTORY
Name of Document: DNP V3:00 Data Object Library
Network File Name: P009-OBL
Original Author: Malcolm Smith/Michael Copps
Date and Version of Preliminary Release: October 8, 1992 Version 0.00A
Associated Software Release(s): DNP V3.00
Revisions Since Preliminary Release
Date
Version
By Whom
Oct. 08/92
Nov. 09/92
Nov. 23/92
Jun. 27/93
Jul. 01/93
Aug. 20/93
Sep. 01/93
Sep. 01/93
July. 08/97
0.00A
0.00B
0.01
0.02
0.02
0.02
0.02
0.02
0.02
MS
MS
LA
MS
JB
JB
JB
MCH
S. Tessari
Pages
Affected
All
All
All
All
All
All
All
All
All
Reason for Changes
Created using P020-0BL
Revised after review and editorials.
Reformatted to WI standards.
Re-structure, addition of objects.
Update and edit as per the review.
Update and addition of new objects.
Update and reformat.
Check and revise format.
Converted to MSWord 6.0
DNP Users Group
DNP PRODUCT DOCUMENTATION
DNP V3.00
DATA OBJECT LIBRARY
Document Version: 0.02
Internal File: P009-OBL
Associated Software Release: DNP V3.00
NOTICE OF RIGHTS - DNP USERS GROUP
The contents of this manual are the property of the DNP Users Group.
Revisions or additions to the definition and functionality of the
Distributed Network Protocol cannot be made without express written
agreement from the DNP Users Group or its duly authorized party. In
addition, no part of this document may be altered or revised or added to
in any form or by any means, except as permitted by written agreement
with the DNP Users Group or a Party duly authorized by the DNP Users
Group.
As a Party, duly authorized by the DNP Users Group, Harris
Corporation has made every reasonable attempt to ensure the
completeness and accuracy of this document, however, the information
contained in this manual is subject to change without notice, and does
not represent a commitment on the part of Harris Corporation or the
DNP Users Group. An update program for DNP documents is provided
upon request by Harris Corporation on behalf of the DNP Users Group.
TRADEMARK NOTICES
Brand and product names mentioned in this document are trademarks or
registered trademarks of their respective companies.
TABLE OF CONTENTS
ABOUT THIS DOCUMENT
PURPOSE OF THIS SPECIFICATION
WHO SHOULD USE THIS SPECIFICATION
HELP AND ADDITIONAL DOCUMENTATION
HOW THIS SPECIFICATION IS ORGANIZED
CONVENTIONS USED IN THIS SPECIFICATION
vi
vi
vi
vi
vii
vii
1. OVERVIEW
1-1
2. DECLARATION RULES FOR INFORMATION ELEMENTS
2.1 GENERAL
2-1
2-1
3. GENERAL RULES
3.1 LIBRARY STRUCTURE
3.2 POINT NUMBERING
3-1
3-1
3-4
4. BINARY INPUT OBJECT DEFINITIONS
4.1 SINGLE-BIT BINARY INPUT
4.2 BINARY INPUT WITH STATUS
4.3 BINARY INPUT CHANGE WITHOUT TIME
4.4 BINARY INPUT CHANGE WITH TIME
4.5 BINARY INPUT CHANGE WITH RELATIVE TIME
4-1
4-1
4-3
4-4
4-6
4-8
5. BINARY OUTPUT OBJECT DEFINITIONS
5.1 BINARY OUTPUT
5.2 BINARY OUTPUT STATUS
5.3 CONTROL RELAY OUTPUT BLOCK
5.4 PATTERN CONTROL BLOCK
5.5 PATTERN MASK
5-1
5-1
5-2
5-3
5-7
5-8
6. COUNTER OBJECT DEFINITIONS
6.1 32-BIT BINARY COUNTER
6.2 16-BIT BINARY COUNTER
6.3 32-BIT DELTA COUNTER
6-1
6-1
6-3
6-5
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i
6.4 16-BIT DELTA COUNTER
6.5 32-BIT COUNTER WITHOUT FLAG
6.6 16-BIT COUNTER WITHOUT FLAG
6.7 32-BIT DELTA COUNTER WITHOUT FLAG
6.8 16-BIT DELTA COUNTER WITHOUT FLAG
6.9 32-BIT FROZEN COUNTER
6.10 16-BIT FROZEN COUNTER
6.11 32-BIT FROZEN DELTA COUNTER
6.12 16-BIT FROZEN DELTA COUNTER
6.13 32-BIT FROZEN COUNTER WITH TIME OF FREEZE
6.14 16-BIT FROZEN COUNTER WITH TIME OF FREEZE
6.15 32-BIT FROZEN DELTA COUNTER WITH TIME OF FREEZE
6.16 16-BIT FROZEN DELTA COUNTER WITH TIME OF FREEZE
6.17 32-BIT FROZEN COUNTER WITHOUT FLAG
6.18 16-BIT FROZEN COUNTER WITHOUT FLAG
6.19 32-BIT FROZEN DELTA COUNTER WITHOUT FLAG
6.20 16-BIT FROZEN DELTA COUNTER WITHOUT FLAG
6.21 32-BIT COUNTER CHANGE EVENT WITHOUT TIME
6.22 16-BIT COUNTER CHANGE EVENT WITHOUT TIME
6.23 32-BIT DELTA COUNTER CHANGE EVENT WITHOUT TIME
6.24 16-BIT DELTA COUNTER CHANGE EVENT WITHOUT TIME
6.25 32-BIT COUNTER CHANGE EVENT WITH TIME
6.26 16-BIT COUNTER CHANGE EVENT WITH TIME
6.27 32-BIT DELTA COUNTER CHANGE EVENT WITH TIME
6.28 16-BIT DELTA COUNTER CHANGE EVENT WITH TIME
6.29 32-BIT COUNTER CHANGE EVENT WITHOUT TIME
6.30 16-BIT FROZEN COUNTER EVENT WITHOUT TIME
6.31 32-BIT FROZEN DELTA COUNTER EVENT WITHOUT TIME
6.32 16-BIT FROZEN DELTA COUNTER WITHOUT TIME
6.33 32-BIT FROZEN COUNTER EVENT WITH TIME
6.34 16-BIT FROZEN COUNTER EVENT WITH TIME
6.35 32-BIT FROZEN DELTA COUNTER EVENT WITH TIME
6.36 16-BIT FROZEN DELTA COUNTER EVENT WITH TIME
7. ANALOG INPUT OBJECT DEFINITIONS
7.1 32-BIT ANALOG INPUT
7.2 16-BIT ANALOG INPUT
7.3 32-BIT ANALOG INPUT WITHOUT FLAG
7.4 16-BIT ANALOG INPUT WITHOUT FLAG
7.5 32-BIT FROZEN ANALOG INPUT
7.6 16-BIT FROZEN ANALOG INPUT
7.7 32-BIT FROZEN ANALOG INPUT WITH TIME OF FREEZE
7.8 16-BIT FROZEN ANALOG INPUT WITH TIME OF FREEZE
7.9 32-BIT FROZEN ANALOG INPUT WITHOUT FLAG
7.10 16-BIT FROZEN ANALOG INPUT WITHOUT FLAG
7.11 32-BIT ANALOG CHANGE EVENT WITHOUT TIME
ii
6-6
6-7
6-8
6-9
6-10
6-11
6-12
6-13
6-14
6-15
6-17
6-19
6-21
6-23
6-24
6-25
6-26
6-27
6-28
6-29
6-30
6-31
6-33
6-35
6-37
6-39
6-40
6-41
6-42
6-43
6-45
6-47
6-49
7-1
7-1
7-3
7-5
7-6
7-7
7-8
7-9
7-11
7-13
7-14
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7.12 16-BIT CHANGE EVENT WITHOUT TIME
7.13 32-BIT ANALOG CHANGE EVENT WITH TIME
7.14 16-BIT ANALOG CHANGE EVENT WITH TIME
7.15 32-BIT FROZEN ANALOG EVENT WITHOUT TIME
7.16 16-BIT FROZEN ANALOG EVENT WITHOUT TIME
7.17 32-BIT FROZEN ANALOG EVENT WITH TIME
7.18 16-BIT FROZEN ANALOG EVENT WITH TIME
7-17
7-19
7-21
7-23
7-25
7-27
7-29
8. ANALOG OUTPUT OBJECT DEFINITIONS
8.1 32-BIT ANALOG OUTPUT STATUS
8.2 16-BIT ANALOG OUTPUT STATUS
8.3 32-BIT ANALOG OUTPUT BLOCK
8.4 16-BIT ANALOG OUTPUT BLOCK
8-1
8-1
8-3
8-4
8-5
9. TIME OBJECT DEFINITIONS
9.1 TIME AND DATE
9.2 TIME AND DATE WITH INTERVAL
9.3 TIME AND DATE CTO
9.4 UN-SYNCHRONIZED TIME AND DATE CTO
9.5 TIME DELAY COARSE
9.6 TIME DELAY FINE
9-1
9-1
9-2
9-4
9-5
9-6
9-7
10. CLASS OBJECT DEFINITIONS
10.1 CLASS 0 DATA
10.2 CLASS 1 DATA
10.3 CLASS 2 DATA
10.4 CLASS 3 DATA
10-1
10-1
10-2
10-3
10-4
11. FILE OBJECT DEFINITIONS
11.1 FILE IDENTIFIER
11-1
11-1
12. DEVICE OBJECT DEFINITIONS
12.1 INTERNAL INDICATIONS
12.2 STORAGE OBJECT
12.3 DEVICE PROFILE
12.4 PRIVATE REGISTRATION OBJECT
12.5 PRIVATE REGISTRATION OBJECT DESCRIPTOR
12-1
12-1
12-2
12-4
12-7
12-8
13. APPLICATION OBJECT DEFINITIONS
13.1 APPLICATION IDENTIFIER
13-1
13-1
14. ALTERNATE NUMERIC OBJECT DEFINITIONS
14.1 SHORT FLOATING POINT
14.2 LONG FLOATING POINT
14.3 EXTENDED FLOATING POINT
14-1
14-1
14-4
14-6
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iii
14.4 SMALL-PACKED BINARY CODED DECIMAL
14.5 MEDIUM-PACKED BINARY CODED DECIMAL
14.6 LARGE-PACKED BINARY CODED DECIMAL
14-8
14-9
14-10
LIST OF ABBREVIATIONS AND ACRONYMS
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LIST OF TABLES
TABLE 2-1 DATA TYPES
TABLE 2-2 BIT POSITIONS
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v
ABOUT THIS DOCUMENT
PURPOSE OF THIS SPECIFICATION
This document defines coding specifications of Distributed Network Protocol (DNP)
information elements or data objects used in the DNP Application Layer. The object
syntax is specified as well as the semantics of each object. In the case of compound
objects, the semantics of each component is described.
WHO SHOULD USE THIS SPECIFICATION
All programmers, implementers or engineers interested in the structure of application
information objects used in the DNP Application Layer.
HELP AND ADDITIONAL DOCUMENTATION
The following documentation may be helpful.
• DNP V3.00 Data Link Layer (P009-0PD.DL).
• DNP V3.00 Application Layer (P009-0PD.APP)
• DNP V3.00 Transport Functions (P009-0PD.TF)
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HOW THIS SPECIFICATION IS ORGANIZED
This document is organized into 13 sections as outlined below.
1. OVERVIEW
2. DECLARATION RULES FOR INFORMATION ELEMENTS
Covers the rules for construction and interpretation of the data objects.
3. GENERAL RULES
Describes the rules governing each of the currently defined objects.
The rest of the sections provide detailed definitions of each type of object.
4. BINARY INPUT OBJECT DEFINITIONS
5. BINARY OUTPUT OBJECT DEFINITIONS
6. COUNTER OBJECT DEFINITIONS
7. ANALOG INPUT OBJECT DEFINITIONS
8. ANALOG OUTPUT OBJECT DEFINITIONS
9. TIME OBJECT DEFINITIONS
10. CLASS OBJECT DEFINITIONS
11. FILE OBJECT DEFINITIONS
12. DEVICE OBJECT DEFINITIONS
13. APPLICATION OBJECT DEFINITIONS
14. ALTERNATE NUMERIC OBJECT DEFINITIONS
LIST OF ABBREVIATIONS AND ACRONYMS
CONVENTIONS USED IN THIS SPECIFICATION
This document deviates from the IEC conventions for bit position numbering. Bit
positions are numbered from 0 through n, with 0 to the top right and n to the bottom left.
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1. OVERVIEW
The intelligent devices which use the DNP Application Layer protocol are capable of
monitoring, controlling and/or producing a large number of different pieces of data both
at the hardware and software levels. These pieces of data, called information elements
(IEC 870-5-3: General Structure of Application Data), are processed and stored as
information objects and these can be packaged for transmission as application data units.
All devices provide stored information elements as information objects in the same
format. These formats are described within this document.
This document will be revised and new information elements or objects will be added as
necessary, and as authorized by the DNP User's Group.
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2. DECLARATION RULES FOR
INFORMATION ELEMENTS
2.1 GENERAL
This section describes the basic rules for the declaration of information elements. These
rules have been derived from the IEC TC57 870 series of standards or drafts. These rules
provide an unambiguous means of describing and representing data irrespective of its
origin. Device profile documents are used to indicate the exact origin and meaning of the
data object for each telecontrol device.
2.1.1 Data Types
All data can be described in its most elemental form as a data type. Data types are
recognized as standard constructs used in most language compilers. DNP information
elements use constructs, as supported by the IEC 870-5-4, as the basis of its descriptions.
Table 2-1 lists the available data types and their meaning.
Data Type
Symbol
Meaning
1. UNSIGNED INTEGER
UI
Positive whole number
2. INTEGER
I
Positive or negative whole number
3. UNSIGNED FIXED POINT
UF
Positive fixed point number
4. FIXED POINT
F
Positive or negative fixed point
number
5. REAL
R
Positive or negative floating-point
number
6. BITSTRING
BS
Assembly of independent bits
7. OCTETSTRING
OS
Assembly of octets
1
Table 2-1 Data Types
1
BOOLEAN is a BITSTRING of size 1.
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2.1.2 Data Size
Each information element is composed of a data type and a size. Data size i, is noted after
the data type symbol notation, and is a cardinal number that specifies the length of the
data field in bits or octets as appropriate. An example is:
BS12 specifies a BITSTRING of 12 bits.
2.1.3 Bit Position
In defining information objects, which are a combination of information elements, the
position of individual bits can be significant. The bit position of a specified field of data
size i is denoted in square brackets [p1..pn], where p1 and pn denote the first and the last
bits of the field. The order of bits is shown in Table 2-2, below.
BITS
7
6
5
OCTETS
4
3
2
1
0
Data Size i
1
7
6
5
4
3
2
1
0
2
15
14
13
12
11
10
9
8
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
j
8j-1
8j-2
8j-3
8j-4
8j-5
8j-6
8j-7
8j-8
Table 2-2 Bit Positions
2.1.4 Element Value
If applicable, a selected range and a selected code of values of the declared data field is
denoted within angle brackets: <v1..vn code>. In general this is declared by the range of
admitted values and by a term that identifies the used code. Terms that identify codes are:
binary code (BIN), binary coded decimal (BCD), ASCII (ASCII), etc. The default code
declaration is binary if no term is used.
2.1.5 Compound Elements
Compound data fields are information elements composed of different data fields with
successive bit allocations. Compound data fields are declared by listing individual data
fields separated by commas or listed in a column, within curly brackets. A following list
declares the data types, the sizes, the bit allocations and the functional purpose of the
individual data fields. The first declared data field begins with bit position 0, the other
fields use successive bit allocations:
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DNP Users Group
'Information Element = CPi {data field 1, data field 2,...}
or
= function 1
{data field 1 = data type 1 size i1[0..i-1]
data field 2 = data type 2 size i2[i1..i1+i2-1] = function 2
etc.}
2.1.6 Sequence Elements
Sequence data fields are information elements composed of different data fields.
Sequences of data fields are declared as compound data fields, however each field begins
bit allocation 0:
'Information Element = SQi {data field 1, data field 2, ...}
or
= function 1
{data field 1 size i1[1..i1]
data field 2 size i2[1..i2]
= function 2
etc.}
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DNP Users Group
3. GENERAL RULES
This section will describe the general rules that apply to the DNP data objects. These
rules apply to all the current objects (except where noted) and all future objects.
3.1 LIBRARY STRUCTURE
The DNP application layer has an 8-bit object and an 8-bit variation field used to denote
the data object. The 8-bit object denotes a general type of data such as static binary data.
The variation of this object gives a different representation of the same data point, such as
the size of the object or whether or not the object has flag information.
There are generally four different categories of data within each data type, as outlined
below:
•
•
•
•
Static Objects: The objects which reflect the current value of the field point or
software point.
Event Objects: The objects which are generated as a result of data changing or
some other stimulant. These are historical objects reflecting the value of data at
some time in the past.
Frozen Static Objects: The objects which reflect the current frozen value of the
field point or software point. Data is frozen as a result of the data freeze requests.
(Refer to the DNP V3.00 Application Layer, P009-0PD.APP.)
Frozen Event Objects: The objects which are generated as a result of frozen data
changing or some other stimulant. These are historical objects reflecting the value
of changed data at some time in the past.
Each category should be represented with a different object. All the classes of a different
data type should also be organized in the same range of object numbers. So far, the
following groupings have been created for all traditional SCADA/DA data types and
several non-traditional data types. These are as follows:
3.1.1 Binary Input
The binary input grouping contains all objects that represent binary (status or Boolean)
input information. The objects 1 - 9 are reserved for these objects.
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3.1.2 Binary Output
The binary output grouping contains all objects that represent binary output or relay
control information. The objects 10 - 19 are reserved for these objects.
3.1.3 Counters
The counter grouping contains all objects that represent counters. The objects 20 - 29 are
reserved for these objects.
3.1.4 Analog Input
The analog input grouping contains all objects that represent analog input information.
The objects 30 - 39 are reserved for these objects.
3.1.5 Analog Output
The analog output grouping contains all objects that represent analog output information.
The objects 40 - 49 are reserved for these objects.
3.1.6 Time
The time grouping contains all objects that represent time in absolute or relative form in
any resolution. The objects 50 - 59 are reserved for these objects.
3.1.7 Class
The class grouping contains all objects that represent data classes or data priority. The
objects 60 - 69 are reserved for these objects.
3.1.8 Files
The files grouping contains all objects that represent files or a file system. The objects 70
- 79 are reserved for these objects.
3.1.9 Devices
The devices grouping contains all objects that represent device (rather than point)
information. The objects 80 - 89 are reserved for these objects.
3.1.10 Applications
The applications grouping contains all objects that represent software applications or
operating system processes. The objects 90 - 99 are reserved for these objects.
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DNP Users Group
3.1.11 Alternate Numeric
The alternate numeric grouping contains all objects that represent alternate or custom
numeric representations. The objects 100 - 109 are reserved for these objects.
3.1.12 Future Expansion
The future expansion grouping is reserved for future or custom expansion of the DNP
protocol. The objects 110 - 254 are reserved for these objects.
3.1.13 Reserved
The objects 0 and 255 are permanently reserved and should not be used to denote any
DNP object. Applications which use these object numbers may not be compatible with
future versions of DNP.
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3-3
3.2 POINT NUMBERING
The following rules apply to the interpretation of the object point number (DNP
Application Layer range field) in conjunction with objects and variations.
Rule 1:
Point i of object x, variation y represents the same physical point as point i, object x,
variation z, where y and z are variations of object x.
For example: A device has 16 running counters (object 20) numbered 0 to 15. Point 5
can be asked for in four different ways:
• Obj 20, var 1, range 5 returns the running value of counter 5 in 32-bit format.
• Obj 20, var 2, range 5 reports the same information, only in 16-bit format.
• Obj 20, var 3, range 5 returns the number of counts accumulated in counter 5 since the
last time it was reported, again in 32-bit format.
• Obj 20, var 4, range 5 reports the same information, only in 16-bit format.
RULE 2:
Point i of object x can be reported in one of many variations (i.e. it can be a 16-bit or 32bit counter). When reported as an event, point i can be returned in either one of the
variations for that object. The exact variation to return is an application specific decision,
however an application should report only ONE event object in any one variation for each
event. When responding to a request for Class data or variation 0 of object x, there should
be only one variation of the object returned.
RULE 3:
Point i within different objects of the same grouping are not necessarily unique, however,
within each of the binary input, binary output, analog input, analog output and counter
groupings the following rules apply.
(a)
(b)
Point i in the static object is the same physical point as point i in the event
object.
Point i in the frozen object is the same physical point as point i in the
frozen event object.
For example: For binary inputs, point i in obj 1 var 1 and 2 is the same point as point i in
obj 2 var 1, 2 and 3 (static and event correlation). For counters, point i in obj 20 var 1, 2,
3, and 4 is the same point as point i in obj 22 var 1, 2, 3, 4, 5, 6, 7, and 8 (static and event
correlation). In addition, point i in obj 21 var 1, 2, 3, 4, 5, 6, 7, and 8 is the same point as
point i in obj 23 var 1, 2, 3, 4, 5, 6, 7, and 8 (frozen and frozen static correlation).
NOTE:
3-4
Point i in obj 20 and point i in obj 21 are NOT necessarily the same point.
There is no direct correlation between frozen and non-frozen objects.
DNP Users Group
Rule 4:
Object groupings which can by definition or due to device limitation have only one point
per object or where the point number is not needed should use the range number 0 or
quantity equals to 1, when using a message format that requires a point number.
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4. BINARY INPUT OBJECT
DEFINITIONS
This section defines the binary input data objects using the rules established in section 2.
DECLARATION RULES FOR INFORMATION ELEMENTS.
4.1 SINGLE-BIT BINARY INPUT
Data Object 01 - Variation: 01
Type: Static
Description:
The single-bit binary input object is used to represent the state of a digital input point
(hardware or software).
Object Coding:
0
BS1 [0..0]
State = BS1 [0] <0,1 BIN>
Narrative:
This single-bit binary input representation is used to transmit binary input states in a
packed format. Transmission of the data object is always performed in complete octets
with unoccupied bit positions set to zero. The following example illustrates the packing
of n of these data objects.
7
6
5
4
3
2
1
0
15
14
13
12
11
10
9
8
0
0
0
n
n-1
n-2
n-3
n-4
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NOTE:
4-2
This variation contains no point status information. For example, on-line,
restart, etc. bits which are part of the binary input with status variation,
are not part of this variation. The use of the single-bit binary input
variation implies that the point is on-line and all other status bits are clear.
(i.e. restart, communication lost, etc. bits are cleared).
DNP Users Group
4.2 BINARY INPUT WITH STATUS
Data Object 01 - Variation: 02
Type: Static
Description:
The binary input with status object is used to represent the state of a digital input point
(hardware or software), and also indicates the status of the point as follows:
The on-line bit indicates that the binary input point has been read successfully. If
this field is set to off-line, the state of the digital point may not be correct.
The restart bit indicates that the field device that originated the data object is
currently restarting. This device may be the device reporting this data object.
The communication lost bit indicates that the device reporting this data object has
lost communication with the originator of the data object.
The remote forced data bit indicates that the state of the binary input has been
forced to its current state at a device other than the end device.
The local forced data bit indicates that the state of the binary input has been
forced to its current state at the end device.
The chatter filter bit indicates that the binary input point has been filtered in order
to remove unneeded transitions in the state of the point.
The state bit indicates the current state of the binary input point.
Object Coding:
7
BS8 [0..7]
On-line
Restart
Communication lost
Remote forced data
Local forced data
Chatter filter
Reserved
State
=
=
=
=
=
=
=
=
6
5
4
3
2
1
0
BS1 [0] <0, off-line; 1, on-line>
BS1 [1] <0, normal; 1, restart>
BS1 [2] <0, normal; 1, lost>
BS1 [3] <0, normal; 1, forced>
BS1 [4] <0, normal; 1, forced>
BS1 [5] <0, normal; 1, filter on>
BS1 [6] <0>
BS1 [7] <0, 1 BIN>
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4.3 BINARY INPUT CHANGE WITHOUT TIME
Data Object 02 - Variation: 01
Type: Event
Description:
The binary input change without time object is used to represent the changed state of a
digital input point (hardware or software) and also indicates the status of the point as
follows:
The on-line bit indicates that the binary input point has been read successfully. If
this field is set to off-line, the state of the digital point may not be correct.
The restart bit indicates that the field device that originated the data object has
been re-started. This device may be the device reporting this data object.
The communication lost bit indicates that the device reporting this data object has
lost communication with the originator of the data object.
The remote forced data bit indicates that the state of the binary input has been
forced to its current state at the originating device.
The local forced data bit indicates that the state of the binary input has been
forced to its current state at the device reporting this data object.
The chatter filter bit indicates that the binary input point has been filtered in order
to remove unneeded transitions in the state of the point.
The state bit indicates the current changed state of the binary input point.
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DNP Users Group
Object Coding:
7
BS8 [0..7]
On-line
Restart
Communication lost
Remote forced data
Local forced data
Chatter filter
Reserved
State
=
=
=
=
=
=
=
=
6
5
4
3
2
1
0
BS1 [0] <0, off-line; 1, on-line>
BS1 [1] <0, normal; 1, restart>
BS1 [2] <0, normal; 1, lost>
BS1 [3] <0, normal; 1, forced>
BS1 [4] <0, normal; 1, forced>
BS1 [5] <0, normal; 1, filter on>
BS1 [6] <0>
BS1 [7] <0,1 BIN>
Narrative:
This object is only reported when the current value is different than the last recorded or
measured value. If the chatter filter is on, this object may only be reported when the new
state has remained constant for a certain period of time.
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4.4 BINARY INPUT CHANGE WITH TIME
Data Object 02 - Variation: 02
Type: Event
Description:
The binary input change with time object is used to represent the changed state of a
digital input point (hardware or software) and the time at which the state changed. It also
indicates the status of the point as follows:
The on-line bit indicates that the binary input point has been read successfully. If
this field is set to off-line, the state of the digital point may not be correct.
The restart bit indicates that the field device that originated the data object has
been re-started. This device may be the device reporting this data object.
The communication lost bit indicates that the device reporting this data object has
lost communication with the originator of the data object.
The remote forced data bit indicates that the state of the binary input has been
forced to its current state at the originating device.
The local forced data bit indicates that the state of the binary input has been
forced to its current state at the device reporting this data object.
The chatter filter bit indicates that the binary input point has been filtered in order
to remove unneeded transitions in the state of the point.
The state bit indicates the current changed state of the binary input point.
The Time of Occurrence indicates the absolute time at which the telecontrol device
detected the change of state. The accuracy of this time will depend on the accuracy of the
individual device.
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DNP Users Group
Object Coding:
FLAG
7
6
5
4
3
2
1
0
TIME OF OCCURRENCE
SQ2
7
6
5
4
3
2
1
0
15
14
13
12
11
10
9
8
23
22
21
20
19
18
17
16
31
30
29
28
27
26
25
24
39
38
37
36
35
34
33
32
47
46
45
44
43
42
41
40
{FLAG
=
Time of Occurrence =
}
BS8 [0..7]
UI48 [0..47] <248 -1 ms>
FLAG
On-line
Restart
Communication lost
Remote forced data
Local forced data
Chatter filter
Reserved
State
}
BS8 [0..7]
BS1 [0] <0, off-line; 1, on-line>
BS1 [1] <0, normal; 1, restart>
BS1 [2] <0, normal; 1, lost>
BS1 [3] <0, normal; 1, forced>
BS1 [4] <0, normal; 1, forced>
BS1 [5] <0, normal; 1, filter on>
BS1 [6] <0>
BS1 [7] <0,1 BIN>
={
=
=
=
=
=
=
=
=
Narrative:
Time of occurrence is recorded as milliseconds since midnight, January 1st, 1970, at zero
hours, zero minutes, seconds, and milliseconds.
DNP V3.00 Data Object Library (Version 0.02)
4-7
4.5 BINARY INPUT CHANGE WITH RELATIVE TIME
Data Object 02 - Variation: 03
Type: Event
Description:
The binary input change with relative time object is used to represent the changed state of
a digital input point (hardware or software), and the relative time at which the state
changed. It also indicates the status of the point as follows:
The on-line bit indicates that the binary input point has been read successfully. If
this field is set to off-line, the state of the digital point may not be correct.
The restart bit indicates that the field device that originated the data object has
been re-started. This device may be the device reporting this data object.
The communication lost bit indicates that the device reporting this data object has
lost communication with the originator of the data object.
The remote forced data bit indicates that the state of the binary input has been
forced to its current state at the originating device.
The local forced data bit indicates that the state of the binary input has been
forced to its current state at the device reporting this data object.
The chatter filter bit indicates that the binary input point has been filtered in order
to remove unneeded transitions in the state of the point.
The state bit indicates the current changed state of the binary input point.
The MSEC field indicates the relative time at which the telecontrol device detected the
change of state. The accuracy of this time will depend on the accuracy of the individual
device.
4-8
DNP Users Group
Object Coding:
FLAG
7
6
5
4
3
2
1
0
MSEC
SQ2
7
6
5
4
3
2
1
0
15
14
13
12
11
10
9
8
{FLAG
MSEC
}
=
=
BS8 [0..7]
UI16 [0..15] <0..216-1>
FLAG
On-line
Restart
Communication lost
Remote forced data
Local forced data
Chatter filter
Reserved
State
}
={
=
=
=
=
=
=
=
=
BS8 [0..7]
BS1 [0] <0, off-line; 1, on-line>
BS1 [1] <0, normal; 1, restart>
BS1 [2] <0, normal; 1, lost>
BS1 [3] <0, normal; 1, forced>
BS1 [4] <0, normal; 1, forced>
BS1 [5] <0, normal; 1, filter on>
BS1 [6] <0>
BS1 [7] <0,1 BIN>
Narrative:
This object MUST be preceded by an absolute time object (common time object or CTO)
or an unsynchronized CTO in the DNP Application Layer message. The CTO is used as
an absolute time base for all following binary input change with relative time objects.
The relative time in each binary input object is added to the CTO absolute time to give
the absolute time at which the binary input change was detected by the device.
DNP V3.00 Data Object Library (Version 0.02)
4-9
4-10
DNP Users Group
5. BINARY OUTPUT OBJECT
DEFINITIONS
This section defines the binary output data objects using the rules established in section 2.
DECLARATION RULES FOR INFORMATION ELEMENTS.
5.1 BINARY OUTPUT
Data Object 10 - Variation: 01
Type: Static
Description:
The binary output object is used to control a digital output point (hardware or software).
The state bit indicates the desired logic state of the digital output point.
Object Coding:
0
BS1 [0..0]
State = BS1 [0] <0,1 BIN>
Narrative:
Transmission of the data object is always pre-formed in complete octets, with unoccupied
bit positions set to zero. The following example illustrates the packing of n of these data
objects:
7
6
5
4
3
2
1
0
15
14
13
12
11
10
9
8
0
0
0
n
n-1
n-2
n-3
n-4
DNP V3.00 Data Object Library (Version 0.02)
5-1
5.2 BINARY OUTPUT STATUS
Data Object 10 - Variation: 02
Type: Static
Description:
The binary output status object is used to indicate the current state of a controlled digital
point and the status of that point as follows:
The on-line bit indicates that the device controlling the binary output point is
operating correctly. A binary output command to this point should work correctly.
If this field is set to off-line, a binary output command to this point would be
unsuccessful.
The restart bit indicates that the field device that originated the data object has
been re-started. This device may be the device reporting this data object.
The communication lost bit indicates that the digital output point could not be
controlled because communications have been lost with the controlled device.
The remote forced data bit indicates that the digital output point has been
controlled at the originating device and the current state is in the state bit.
The local forced data bit indicates that the digital output point has been controlled
at this device and the current state is in the state bit.
The state bit indicates the current state of the binary output point.
Object Coding:
7
BS8 [0..7]
On-line
Restart
Communication lost
Remote forced data
Local forced data
Reserved
Reserved
State
5-2
=
=
=
=
=
=
=
=
6
5
4
3
2
1
0
BS1 [0] <0, off-line; 1, on-line>
BS1 [1] <0, normal; 1, restart>
BS1 [2] <0, normal; 1, lost>
BS1 [3] <0, normal; 1, forced>
BS1 [4] <0, normal; 1, forced>
BS1 [5] <0>
BS1 [6] <0>
BS1 [7] <0,1 BIN>
DNP Users Group
5.3 CONTROL RELAY OUTPUT BLOCK
Data Object 12 - Variation: 01
Type: Static
Description:
The control relay output Block information object contains digital output control
parameters. These parameters define the type and duration of the digital output.
The control code field indicates the control function to perform. The applicability
of this code will depend on the type of hardware used in the end device.
The count field indicates the number of times that the control operation should be
performed in succession.
The on-time field specifies the amount of time the digital output is to be turned on
(may not apply to all control types).
The off-time field specifies the amount of time the digital output is to be turned off
(may not apply to all control types).
DNP V3.00 Data Object Library (Version 0.02)
5-3
Object Coding:
Control Code
7
6
5
4
3
2
1
0
2
1
0
Count
7
6
5
4
3
On Time
31
0
Off Time
31
0
Status
7
SQ4
{Control code
Count
On-time
Off-time
Status
Reserved
}
Control code
Code
Queue
Clear
Trip/Close
}
Narrative:
Trip/Close:
5-4
6
=
=
=
=
=
=
={
=
=
=
=
5
4
3
2
1
0
BS8 [0..7]
UI8 [0..7] <0..255>
UI32 [0..31] <0..232-1, ms>
UI32 [0..31] <0..232-1, ms>
UI7 [0..6] <0..127>
[0..0] <0..1>
BS4 [0..3] <0..15>
BS1 [4] <0, normal; 1, requeued>
BS1 [5] <0, normal; 1, clear>
BS2 [6..7] <00, NUL; 01, Close; 10, Trip>
This field determines which control relay to activate in a system where a
trip and close relay pair is used to energize and de-energize the field
points. The NUL value in this field can be used to activate the field point
select relay only without activating the trip or close relays. In a system
without field point select relays, the NUL value would not perform any
control operation. In a system without trip/close relays, this field should
always be NUL to indicate a normal digital control operation where the
exact control point is inherently known. This field does not support having
both the trip and close attributes simultaneously, as this is an illegal
operation for the system.
DNP Users Group
Count:
The Count field determines how many times the control is executed. If the
count is 0, do not execute the control. When the count reaches 0, the
control is complete.
Code:
The control block can be used with devices which support control queuing
on a point per point basis or devices which have other control
mechanisms. In the former, any control command should be queued for the
particular point in question. In the latter, each control is performed until
completion before the next control is accepted for that point.
Queue:
If the control code is NUL then no control operation is queued, and the
queue is cleared of all controls including the presently running control if
the clear attribute is set.
When the control function is executed and completed, it is removed from
the queue. If the control block for that operation had the queue attribute
set, the control operation is re-queued (to the back of the queue) for that
point.
Clear:
If the control operation has the clear attribute set, all control operations are
removed from the queue including the presently running control and this
control operation is performed.
The meaning of the code field and the operation to perform is determined by the
following:
0:
NUL operation. No operation specified. Only the R attribute is processed.
1:
Pulse On - The point(s) is turned on for the specified on-time, turned off
for the specified off-time and left in the off state.
2:
Pulse Off - The point(s) is turned off for the specified off-time, then turned
on for the specified on-time and left in the on state.
3:
Latch On - This latches the point(s) on.
4:
Latch Off - This latches the point(s) off.
5 - 15:
Undefined.
Queue:
Place operation at the back of the control queue when complete.
Clear:
Cancel currently running operation and remove queued operations on
affected points immediately before activating this new operation (if not
NUL).
DNP V3.00 Data Object Library (Version 0.02)
5-5
The reserved bit of the control point after the operation can be determined
if the control output is on.
The success or failure of the requested control operation is returned in the
status field. The meaning of this field is determined as follows:
0:
Request accepted, initiated, or queued.
1:
Request not accepted as the operate message was received after the
arm timer timed out. The arm timer was started when the select
operation for the same point was received.
2:
No previous matching select message (i.e. an operate message was
sent to activate a control point that was not previously armed with
the select message.
3:
Request not accepted as there were formatting errors in the control
request (either select, operate, or direct operate).
4:
Control operation not supported for this point.
5:
Request not accepted, as the control queue is full or the point is
already active.
6:
Request not accepted because of control hardware problems.
7 - 127:Undefined.
5-6
DNP Users Group
5.4 PATTERN CONTROL BLOCK
Data Object 12 - Variation: 02
Type: Static
Description:
The pattern control block (PCB) object contains digital output control parameters for
pattern type controls. These parameters define the type and duration of the digital output
for each of the affected points. The PCB object defines all the parameters for the
subsequent pattern mask objects which follow this object in the message. These
parameters contained in the PCB influence all the pattern mask object(s) that immediately
follow the PCB object, until the next PCB in the message.
The combination of this object and the pattern mask objects that follow will specify a
number (0 or more) of control operations to perform (i.e. the same operation on different
points). All these controls must be performed in parallel. The meaning of all fields,
attributes, and parameters are identical to the control relay output block except that the
queuing attributes are not valid. This is, the pattern control is not meant to be re-queued.
Object Coding:
Control Code
7
6
5
4
3
2
1
0
3
2
1
0
Count
7
6
5
4
On Time
31
0
Off Time
31
0
Status
7
6
5
4
DNP V3.00 Data Object Library (Version 0.02)
3
2
1
0
5-7
5.5 PATTERN MASK
Data Object 12 - Variation: 03
Type: Static
Description:
The pattern mask object is used to select from a range of possible control points that have to
be executed in parallel.
This object is used in conjunction with the PCB object to specify both the control points to
operate and the parameters that determine the control operation.
If the mask bit is set to active, then the parameters specified in the preceding PCB are
applied to a specified point for each pattern mask object and a control operation is generated
for the point.
Object Coding:
M
BS1 [0..0]
Mask = BS1 [0] <0, inactive; 1, active>
Narrative:
This single-bit pattern mask is typically sent in groups. Transmission of the data object is
always performed in complete octets with unoccupied bit positions set to zero. The
following example illustrates the packing of n of these data objects.
5-8
7
6
5
4
3
2
1
0
15
14
13
12
11
10
9
8
0
0
0
n
n-1
n-2
n-3
n-4
DNP Users Group
6. COUNTER OBJECT DEFINITIONS
This section defines the counter data objects using the rules established in section 2..
DECLARATION RULES FOR INFORMATION ELEMENTS.
6.1 32-BIT BINARY COUNTER
Data Object 20 - Variation: 01
Type: Static
Description:
The 32-bit binary counter represents an accumulated value. This can be accumulated pulses
or transitions from a hardware or software point.
The value field shows the current value of the counter at the time of reporting or last
reported value from the originating device. This value increments indefinitely until a
counter clear operation is performed in which case the value is reset to 0.
The flag field has the same meaning as in previous objects, with the following inclusion:
• When set, the roll-over bit indicates that the accumulated value has exceeded the last
reported recordable value (232-1). The counter value has been reset to 0 upon the rollover and counting has resumed as normal. This bit is cleared when the counter value
(plus the roll-over state) is reported.
DNP V3.00 Data Object Library (Version 0.02)
6-1
Object Coding:
FLAG
7
6
5
4
3
2
1
0
Value
31
SQ2
6-2
0
{FLAG
Value
}
=
=
BS8 [0..7]
UI32 [0..31] <0..232-1>
FLAG
On-line
Restart
Communication lost
Remote forced data
Local forced data
Roll-over
Roll-over
Reserved
Reserved
}
={
=
=
=
=
=
=
=
=
=
BS1 [0] <0, off-line; 1, on-line>
BS1 [1] <0, normal; 1, restart>
BS1 [2] <0, normal; 1, lost>
BS1 [3] <0, normal; 1, forced>
BS1 [4] <0, normal; 1, forced>
BS1 [4] <0, normal; 1, roll-over>
BS1 [5] <0, normal; 1, roll-over>
BS1 [6] <0>
BS1 [7] <0>
DNP Users Group
6.2 16-BIT BINARY COUNTER
Data Object 20 - Variation: 02
Type: Static
Description:
The 16-bit binary counter represents an accumulated value. This can be accumulated pulses
or transitions from a hardware or software point.
The value field shows the current value of the counter at the time of reporting or last
reported value from the originating device. This value increments indefinitely until a
counter clear operation is performed in which case the value is reset to 0.
The flag field has the same meaning as in previous objects, with the following inclusion:
• When set, the roll-over bit indicates that the accumulated value has exceeded the
maximum possible recordable value (216-1). The counter value has been reset to 0 upon
roll-over, and counting has resumed as normal. This bit is cleared when the counter value
(plus the roll-over state) is reported.
DNP V3.00 Data Object Library (Version 0.02)
6-3
Object Coding:
FLAG
7
6
5
4
3
2
1
0
Value
15
SQ2
6-4
0
{FLAG
Value
}
=
=
BS8 [0..7]
UI16 [0..15] <0..216-1>
FLAG
On-line
Restart
Communication lost
Remote forced data
Local forced data
Roll-over
Roll-over
Reserved
Reserved
}
={
=
=
=
=
=
=
=
=
=
BS1 [0] <0, off-line; 1, on-line>
BS1 [1] <0, normal; 1, restart>
BS1 [2] <0, normal; 1, lost>
BS1 [3] <0, normal; 1, forced>
BS1 [4] <0, normal; 1, forced>
BS1 [4] <0, normal; 1, roll-over>
BS1 [5] <0, normal; 1, roll-over>
BS1 [6] <0>
BS1 [7] <0>
DNP Users Group
6.3 32-BIT DELTA COUNTER
Data Object 20 - Variation: 03
Type: Static
Description:
The 32-bit delta counter represents a value that has accumulated since the last value was
reported. This can be accumulated pulses or transitions from a hardware or software point.
The value field shows the current value of the counter at the time of reporting or last
reported value from the originating device. This value increments until it is reported at
which point it is reset to 0.
The flag field has the same meaning as in previous objects, with the following inclusion:
• When set, the roll-over bit indicates that the accumulated value has exceeded the
maximum possible recordable value (232-1). The counter value has been reset to 0 upon
roll-over, and counting has resumed as normal. This bit is cleared when the counter value
(plus the roll-over state) is reported.
Object Coding:
FLAG
7
6
5
4
3
2
1
0
Value
31
SQ2
0
{FLAG
Value
}
=
=
BS8 [0..7]
UI32 [0..31] <0..232-1>
FLAG
On-line
Restart
Communication lost
Remote forced data
Local forced data
Roll-over
Roll-over
Reserved
Reserved
}
={
=
=
=
=
=
=
=
=
=
BS1 [0] <0, off-line; 1, on-line>
BS1 [1] <0, normal; 1, restart>
BS1 [2] <0, normal; 1, lost>
BS1 [3] <0, normal; 1, forced>
BS1 [4] <0, normal; 1, forced>
BS1 [4] <0, normal; 1, roll-over>
BS1 [5] <0, normal; 1, roll-over>
BS1 [6] <0>
BS1 [7] <0>
DNP V3.00 Data Object Library (Version 0.02)
6-5
6.4 16-BIT DELTA COUNTER
Data Object 20 - Variation: 04
Type: Static
Description:
The 16-bit delta counter represents a value that has accumulated since the last value was
reported. This can be accumulated pulses or transitions from a hardware or software point.
The value field shows the current value of the counter at the time of reporting or last
reported value from the originating device. This value increments until it is reported at
which point it is reset to 0.
The flag field has the same meaning as in previous objects, with the following inclusion:
• When set, the roll-over bit indicates that the accumulated value has exceeded the
maximum possible recordable value (216-1). The counter value has been reset to 0 upon
the roll-over and counting has resumed as normal. This bit is cleared when the counter
value (plus the roll-over state) is reported.
Object Coding:
FLAG
7
6
5
4
3
2
1
0
Value
15
SQ2
6-6
0
{FLAG
Value
}
=
=
BS8 [0..7]
UI16 [0..15] <0..216-1>
FLAG
On-line
Restart
Communication lost
Remote forced data
Local forced data
Roll-over
Roll-over
Reserved
Reserved
}
={
=
=
=
=
=
=
=
=
=
BS1 [0] <0, off-line; 1, on-line>
BS1 [1] <0, normal; 1, restart>
BS1 [2] <0, normal; 1, lost>
BS1 [3] <0, normal; 1, forced>
BS1 [4] <0, normal; 1, forced>
BS1 [4] <0, normal; 1, roll-over>
BS1 [5] <0, normal; 1, roll-over>
BS1 [6] <0>
BS1 [7] <0>
DNP Users Group
6.5 32-BIT COUNTER WITHOUT FLAG
Data Object 20 - Variation: 05
Type: Static
Description:
The 32-bit binary counter represents an accumulated value. This can be accumulated pulses
or transitions from a hardware or software point.
The value field shows the current value of the counter at the time of reporting or last
reported value from the originating device. This value increments indefinitely until a
counter clear operation is performed in which case the value is reset to 0.
Object Coding:
Value
31
SQ2
{Value =
}
NOTE:
0
UI32 [0..31] <0..232-1>
The use of this variation implies that the input point is on-line and that all
other flag bits are normal (i.e. this variation implies that flag = 1).
DNP V3.00 Data Object Library (Version 0.02)
6-7
6.6 16-BIT COUNTER WITHOUT FLAG
Data Object 20 - Variation: 06
Type: Static
Description:
The 16-bit binary counter represents an accumulated value. This can be accumulated pulses
or transitions from a hardware or software point.
The value field shows the current value of the counter at the time of reporting or last
reported value from the originating device. This value increments indefinitely until a
counter clear operation is performed in which case the value is reset to 0.
Object Coding:
Value
15
SQ2
{Value =
}
NOTE:
6-8
0
UI16 [0..15] <0..216-1>
The use of this variation implies that the input point is on-line and that all
other flag bits are normal (i.e. this variation implies that flag = 1).
DNP Users Group
6.7 32-BIT DELTA COUNTER WITHOUT FLAG
Data Object 20 - Variation: 07
Type: Static
Description:
The 32-bit delta counter represents a value that has accumulated since the last value was
reported. This can be accumulated pulses or transitions from a hardware or software point.
The value field shows the current value of the counter at the time of reporting or last
reported value from the originating device. This value increments until it is reported at
which point it is reset to 0.
Object Coding:
Value
31
SQ2
{Value =
}
NOTE:
0
UI32 [0..31] <0..232-1>
The use of this variation implies that the input point is on-line and that all
other flag bits are normal (i.e. this variation implies that flag = 1).
DNP V3.00 Data Object Library (Version 0.02)
6-9
6.8 16-BIT DELTA COUNTER WITHOUT FLAG
Data Object 20 - Variation: 08
Type: Static
Description:
The 16-bit delta counter represents a value that has accumulated since the last value was
reported. This can be accumulated pulses or transitions from a hardware or software point.
The value field shows the current value of the counter at the time of reporting or last
reported value from the originating device. This value increments until it is reported at
which point it is reset to 0.
Object Coding:
Value
15
SQ2
{Value =
}
NOTE:
6-10
0
UI16 [0..15] <0..216-1>
The use of this variation implies that the input point is on-line and that all
other flag bits are normal (i.e. this variation implies that flag = 1).
DNP Users Group
6.9 32-BIT FROZEN COUNTER
Data Object 21 - Variation: 01
Type: Frozen Static
Description:
The 32-bit frozen counter is a compound information object which contains information
about a counter which was previously frozen.
The frozen value shows the value of the counter when the last counter freeze was performed
at the originating device.
The flag field has the same meaning as in previous objects.
Object Coding:
FLAG
7
6
5
4
3
2
1
0
Frozen Value
31
SQ2
0
{FLAG
Frozen Value
=
=
BS8 [0..7]
UI32 [0..31] <0..232-1>
FLAG
On-line
Restart
Communication lost
Remote forced data
Local forced data
Roll-over
Roll-over
Reserved
Reserved
}
={
=
=
=
=
=
=
=
=
=
BS1 [0] <0, off-line; 1, on-line>
BS1 [1] <0, normal; 1, restart>
BS1 [2] <0, normal; 1, lost>
BS1 [3] <0, normal; 1, forced>
BS1 [4] <0, normal; 1, forced>
BS1 [4] <0, normal; 1, roll-over>
BS1 [5] <0, normal; 1, roll-over>
BS1 [6] <0>
BS1 [7] <0>
DNP V3.00 Data Object Library (Version 0.02)
6-11
6.10 16-BIT FROZEN COUNTER
Data Object 21 - Variation: 02
Type: Frozen Static
Description:
The 16-bit frozen counter is a compound information object that contains information about
a counter that was previously frozen. The counter accumulates pulses or transitions from a
hardware or software point.
The frozen value shows the value of the counter when the last counter freeze was performed
at the originating device.
The flag field has the same meaning as in previous objects.
Object Coding:
FLAG
7
6
5
4
3
2
1
0
Frozen Value
15
SQ2
6-12
0
{FLAG
Frozen Value
}
=
=
BS8 [0..7]
UI16 [0..15] <0..216-1>
FLAG
On-line
Restart
Communication lost
Remote forced data
Local forced data
Roll-over
Roll-over
Reserved
Reserved
}
={
=
=
=
=
=
=
=
=
=
BS1 [0] <0, off-line; 1, on-line>
BS1 [1] <0, normal; 1, restart>
BS1 [2] <0, normal; 1, lost>
BS1 [3] <0, normal; 1, forced>
BS1 [4] <0, normal; 1, forced>
BS1 [4] <0, normal; 1, roll-over>
BS1 [5] <0, normal; 1, roll-over>
BS1 [6] <0>
BS1 [7] <0>
DNP Users Group
6.11 32-BIT FROZEN DELTA COUNTER
Data Object 21 - Variation: 03
Type: Frozen Static
Description:
The 32-bit frozen delta counter represents a frozen value that has accumulated since the last
value was reported. This can be accumulated pulses or transitions from a hardware or
software point.
The frozen value shows the value of the counter when the last counter freeze was performed
at the originating device.
The flag field has the same meaning as in previous objects.
Object Coding:
FLAG
7
6
5
4
3
2
1
0
Frozen Value
31
SQ2
0
{FLAG
Frozen Value
=
=
BS8 [0..7]
UI32 [0..31] <0..232-1>
FLAG
On-line
Restart
Communication lost
Remote forced data
Local forced data
Roll-over
Roll-over
Reserved
Reserved
}
={
=
=
=
=
=
=
=
=
=
BS1 [0] <0, off-line; 1, on-line>
BS1 [1] <0, normal; 1, restart>
BS1 [2] <0, normal; 1, lost>
BS1 [3] <0, normal; 1, forced>
BS1 [4] <0, normal; 1, forced>
BS1 [4] <0, normal; 1, roll-over>
BS1 [5] <0, normal; 1, roll-over>
BS1 [6] <0>
BS1 [7] <0>
DNP V3.00 Data Object Library (Version 0.02)
6-13
6.12 16-BIT FROZEN DELTA COUNTER
Data Object 21 - Variation: 04
Type: Frozen Static
Description:
The 16-bit frozen delta counter represents a frozen value that has accumulated since the last
value was reported. This can be accumulated pulses or transitions from a hardware or
software point.
The frozen value shows the value of the counter when the last counter freeze was performed
at the originating device.
The flag field has the same meaning as in previous objects.
Object Coding:
FLAG
7
6
5
4
3
2
1
0
Frozen Value
15
SQ2
6-14
0
{FLAG
Frozen Value
}
=
=
BS8 [0..7]
UI16 [0..15] <0..216-1>
FLAG
On-line
Restart
Communication lost
Remote forced data
Local forced data
Roll-over
Roll-over
Reserved
Reserved
}
={
=
=
=
=
=
=
=
=
=
BS1 [0] <0, off-line; 1, on-line>
BS1 [1] <0, normal; 1, restart>
BS1 [2] <0, normal; 1, lost>
BS1 [3] <0, normal; 1, forced>
BS1 [4] <0, normal; 1, forced>
BS1 [4] <0, normal; 1, roll-over>
BS1 [5] <0, normal; 1, roll-over>
BS1 [6] <0>
BS1 [7] <0>
DNP Users Group
6.13 32-BIT FROZEN COUNTER WITH TIME OF FREEZE
Data Object 21 - Variation: 05
Type: Frozen Static
Description:
The 32-bit frozen counter with time of freeze is a compound information object which
contains information about a counter which was previously frozen. The counter
accumulates pulses or transitions from a hardware or software point.
The frozen value shows the value of the counter when the time was time of freeze.
The time of freeze field contains a time that this object was frozen. This time corresponds to
the frozen value so that the current value of this object at time of freeze is frozen value.
The flag field has the same meaning as in previous objects.
DNP V3.00 Data Object Library (Version 0.02)
6-15
Object Coding:
FLAG
7
6
5
4
3
2
1
0
Frozen Value
31
0
Time of Freeze
47
SQ4
0
{FLAG
Frozen value
Time of Freeze
}
=
=
=
BS8 [0..7]
UI32 [0..31] <0..232-1>
UI48 [0..47] <248 -1 ms>
FLAG
On-line
Restart
Communication lost
Remote forced data
Local forced data
Roll-over
Roll-over
Reserved
Reserved
}
={
=
=
=
=
=
=
=
=
=
BS1 [0] <0, off-line; 1, on-line>
BS1 [1] <0, normal; 1, restart>
BS1 [2] <0, normal; 1, lost>
BS1 [3] <0, normal; 1, forced>
BS1 [4] <0, normal; 1, forced>
BS1[4] <0, normal; 1, roll-over>
BS1 [5] <0, normal; 1, roll-over>
BS1 [6] <0>
BS1 [7] <0>
Narrative:
Time of freeze is recorded as milliseconds since midnight, January 1st, 1970, at zero hours,
zero minutes, seconds, and milliseconds.
6-16
DNP Users Group
6.14 16-BIT FROZEN COUNTER WITH TIME OF FREEZE
Data Object 21 - Variation: 06
Type: Frozen Static
Description:
The 16-bit frozen counter with time of freeze is a compound information object which
contains information about a counter which was previously frozen. The counter
accumulates pulses or transitions from a hardware or software point.
The frozen value shows the value of the counter when the time was time of freeze.
The time of freeze field contains a time that this object was frozen. This time corresponds to
the frozen value so that the current value of this object at time of freeze is frozen value.
The flag field has the same meaning as in previous objects.
DNP V3.00 Data Object Library (Version 0.02)
6-17
Object Coding:
FLAG
7
6
5
4
3
2
1
0
Frozen Value
15
0
Time of Freeze
47
SQ4
0
{FLAG
Frozen value
Time of Freeze
}
=
=
=
BS8 [0..7]
UI16 [0..15] <0..216-1>
UI48 [0..47] <248 -1 ms>
FLAG
On-line
Restart
Communication lost
Remote forced data
Local forced data
Roll-over
Roll-over
Reserved
Reserved
}
={
=
=
=
=
=
=
=
=
=
BS1 [0] <0, off-line; 1, on-line>
BS1 [1] <0, normal; 1, restart>
BS1 [2] <0, normal; 1, lost>
BS1 [3] <0, normal; 1, forced>
BS1 [4] <0, normal; 1, forced>
BS1[4] <0, normal; 1, roll-over>
BS1 [5] <0, normal; 1, roll-over>
BS1 [6] <0>
BS1 [7] <0>
Narrative:
Time of freeze is recorded as milliseconds since midnight, January 1st, 1970, at zero hours,
zero minutes, seconds, and milliseconds.
6-18
DNP Users Group
6.15 32-BIT FROZEN DELTA COUNTER WITH TIME OF FREEZE
Data Object 21 - Variation: 07
Type: Frozen Static
Description:
The 32-bit frozen delta counter with time of freeze represents a frozen value that has
accumulated since the last value was reported. This can be accumulated pulses or transitions
from a hardware or software point.
The frozen value shows the value of the counter when the time was time of freeze.
The time of freeze field contains a time that this object was frozen. This time corresponds to
the frozen value so that the current value of this object at time of freeze is frozen value.
The flag field has the same meaning as in previous objects.
DNP V3.00 Data Object Library (Version 0.02)
6-19
Object Coding:
FLAG
7
6
5
4
3
2
1
0
Frozen value
31
0
Time of Freeze
47
SQ4
0
{FLAG
Frozen value
Time of Freeze
}
=
=
=
BS8 [0..7]
UI32 [0..31] <0..232-1>
UI48 [0..47] <248 -1 ms>
FLAG
On-line
Restart
Communication lost
Remote forced data
Local forced data
Roll-over
Roll-over
Reserved
Reserved
}
={
=
=
=
=
=
=
=
=
=
BS1 [0] <0, off-line; 1, on-line>
BS1 [1] <0, normal; 1, restart>
BS1 [2] <0, normal; 1, lost>
BS1 [3] <0, normal; 1, forced>
BS1 [4] <0, normal; 1, forced>
BS1 [4] <0, normal; 1, roll-over>
BS1 [5] <0, normal; 1, roll-over>
BS1 [6] <0>
BS1 [7] <0>
Narrative:
Time of freeze is recorded as milliseconds since midnight, January 1st, 1970, at zero hours,
zero minutes, seconds, and milliseconds.
6-20
DNP Users Group
6.16 16-BIT FROZEN DELTA COUNTER WITH TIME OF FREEZE
Data Object 21 - Variation: 08
Type: Frozen Static
Description:
The 16-bit frozen delta counter with time of freeze represents a frozen value that has
accumulated since the last value was reported. This can be accumulated pulses or transitions
from a hardware or software point.
The frozen value shows the value of the counter when the time was time of freeze.
The time of freeze field contains a time that this object was frozen. This time corresponds to
the frozen value so that the current value of this object at time of freeze is frozen value.
The flag field has the same meaning as in previous objects.
DNP V3.00 Data Object Library (Version 0.02)
6-21
Object Coding:
FLAG
7
6
5
4
3
2
1
0
Frozen value
15
0
Time of Freeze
47
SQ4
0
{FLAG
Frozen value
Time of Freeze
}
=
=
=
BS8 [0..7]
UI16 [0..15] <0..216-1>
UI48 [0..47] <248 -1 ms>
FLAG
On-line
Restart
Communication lost
Remote forced data
Local forced data
Roll-over
Roll-over
Reserved
Reserved
}
={
=
=
=
=
=
=
=
=
=
BS1 [0] <0, off-line; 1, on-line>
BS1 [1] <0, normal; 1, restart>
BS1 [2] <0, normal; 1, lost>
BS1 [3] <0, normal; 1, forced>
BS1 [4] <0, normal; 1, forced>
BS1 [4] <0, normal; 1, roll-over>
BS1 [5] <0, normal; 1, roll-over>
BS1 [6] <0>
BS1 [7] <0>
Narrative:
Time of freeze is recorded as milliseconds since midnight, January 1st, 1970, at zero hours,
zero minutes, seconds, and milliseconds.
6-22
DNP Users Group
6.17 32-BIT FROZEN COUNTER WITHOUT FLAG
Data Object 21 - Variation: 09
Type: Frozen Static
Description:
The 32-bit frozen counter is a compound information object which contains information
about a counter which was previously frozen.
The frozen value shows the value of the counter when the last counter freeze was performed
at the originating device.
Object Coding:
Frozen Value
31
SQ2
{Frozen Value =
}
NOTE:
0
UI32 [0..31] <0..232-1>
The use of this variation implies that the input point is on-line and that all
other flag bits are normal (i.e. this variation implies that flag = 1).
DNP V3.00 Data Object Library (Version 0.02)
6-23
6.18 16-BIT FROZEN COUNTER WITHOUT FLAG
Data Object 21 - Variation: 10
Type: Frozen Static
Description:
The 16-bit frozen counter is a compound information object which contains information
about a counter which was previously frozen. The counter accumulates pulses or transitions
from a hardware or software point.
The frozen value shows the value of the counter when the last counter freeze was performed
at the originating device.
Object Coding:
Frozen Value
15
SQ2
NOTE:
6-24
{Frozen Value
}
0
=
UI16 [0..15] <0..216-1>
The use of this variation implies that the input point is on-line and that all
other flag bits are normal (i.e. this variation implies that flag = 1).
DNP Users Group
6.19 32-BIT FROZEN DELTA COUNTER WITHOUT FLAG
Data Object 21 - Variation: 11
Type: Frozen Static
Description:
The 32-bit frozen delta counter represents a frozen value that has accumulated since the last
value was reported. This can be accumulated pulses or transitions from a hardware or
software point.
The frozen value shows the value of the counter when the last counter freeze was performed
at the originating device.
Object Coding:
Frozen Value
31
SQ2
{Frozen Value =
}
NOTE:
0
UI32 [0..31] <0..232-1>
The use of this variation implies that the input point is on-line and that all
other flag bits are normal (i.e. this variation implies that flag = 1).
DNP V3.00 Data Object Library (Version 0.02)
6-25
6.20 16-BIT FROZEN DELTA COUNTER WITHOUT FLAG
Data Object 21 - Variation: 12
Type: Frozen Static
Description:
The 16-bit frozen delta counter represents a frozen value that has accumulated since the last
value was reported. This can be accumulated pulses or transitions from a hardware or
software point.
The frozen value shows the value of the counter when the last counter freeze was performed
at the originating device.
Object Coding:
Frozen Value
15
SQ2
{Frozen Value =
}
NOTE:
6-26
0
UI16 [0..15] <0..216-1>
The use of this variation implies that the input point is on-line and that all
other flag bits are normal (i.e. this variation implies that flag = 1).
DNP Users Group
6.21 32-BIT COUNTER CHANGE EVENT WITHOUT TIME
Data Object 22 - Variation: 01
Type: Event
Description:
The 32-bit counter change event without time represents a counter value that, since last
reported, has exceeded a configured count. This can be accumulated pulses or transitions
from a hardware or software point.
The current value field shows the value of the counter which generated the event.
The flag field has the same meaning as in previous objects.
Object Coding:
FLAG
7
6
5
4
3
2
1
0
Current value
31
SQ4
0
{FLAG
Current value
}
=
=
BS8 [0..7]
UI32 [0..31] <0..232-1>
FLAG
On-line
Restart
Communication lost
Remote forced data
Local forced data
Roll-over
Roll-over
Reserved
Reserved
}
={
=
=
=
=
=
=
=
=
=
BS1 [0] <0, off-line; 1, on-line>
BS1 [1] <0, normal; 1, restart>
BS1 [2] <0, normal; 1, lost>
BS1 [3] <0, normal; 1, forced>
BS1 [4] <0, normal; 1, forced>
BS1 [4] <0, normal; 1, roll-over>
BS1 [5] <0, normal; 1, roll-over>
BS1 [6] <0>
BS1 [7] <0>
DNP V3.00 Data Object Library (Version 0.02)
6-27
6.22 16-BIT COUNTER CHANGE EVENT WITHOUT TIME
Data Object 22 - Variation: 02
Type: Event
Description:
The 16-bit counter change event without time represents a counter value that has exceeded a
configured deadband. This can be accumulated pulses or transitions from a hardware or
software point.
The current value field shows the value of the counter which generated the event.
The flag field has the same meaning as in previous objects.
Object Coding:
FLAG
7
6
5
4
3
2
1
0
Current value
15
SQ4
6-28
0
{FLAG
Current value
}
=
=
BS8 [0..7]
UI16 [0..15] <0..216-1>
FLAG
On-line
Restart
Communication lost
Remote forced data
Local forced data
Roll-over
Roll-over
Reserved
Reserved
}
={
=
=
=
=
=
=
=
=
=
BS1 [0] <0, off-line; 1, on-line>
BS1 [1] <0, normal; 1, restart>
BS1 [2] <0, normal; 1, lost>
BS1 [3] <0, normal; 1, forced>
BS1 [4] <0, normal; 1, forced>
BS1 [4] <0, normal; 1, roll-over>
BS1 [5] <0, normal; 1, roll-over>
BS1 [6] <0>
BS1 [7] <0>
DNP Users Group
6.23 32-BIT DELTA COUNTER CHANGE EVENT WITHOUT TIME
Data Object 22 - Variation: 03
Type: Event
Description:
The 32-bit delta counter change event without time represents a delta counter value that has
exceeded a configured deadband. This can be accumulated pulses or transitions from a
hardware or software point.
The delta value field shows the change of the counter which generated the event.
The flag field has the same meaning as in previous objects.
Object Coding:
FLAG
7
6
5
4
3
2
1
0
Delta value
31
SQ4
0
{FLAG
Current value
}
=
=
BS8 [0..7]
UI32 [0..31] <0..232-1>
FLAG
On-line
Restart
Communication lost
Remote forced data
Local forced data
Roll-over
Roll-over
Reserved
Reserved
}
={
=
=
=
=
=
=
=
=
=
BS1 [0] <0, off-line; 1, on-line>
BS1 [1] <0, normal; 1, restart>
BS1 [2] <0, normal; 1, lost>
BS1 [3] <0, normal; 1, forced>
BS1 [4] <0, normal; 1, forced>
BS1 [4] <0, normal; 1, roll-over>
BS1 [5] <0, normal; 1, roll-over>
BS1 [6] <0>
BS1 [7] <0>
DNP V3.00 Data Object Library (Version 0.02)
6-29
6.24 16-BIT DELTA COUNTER CHANGE EVENT WITHOUT TIME
Data Object 22 - Variation: 04
Type: Event
Description:
The 16-bit delta counter change event without time represents a delta counter value that has
exceeded a configured deadband. This can be accumulated pulses or transitions from a
hardware or software point.
The delta value field shows the change of the counter which generated the event.
The flag field has the same meaning as in previous objects.
Object Coding:
FLAG
7
6
5
4
3
2
1
0
Delta value
15
SQ4
6-30
0
{FLAG
Current value
=
=
BS8 [0..7]
UI32 [0..16] <0..216-1>}
FLAG
On-line
Restart
Communication lost
Remote forced data
Local forced data
Roll-over
Roll-over
Reserved
Reserved
}
={
=
=
=
=
=
=
=
=
=
BS1 [0] <0, off-line; 1, on-line>
BS1 [1] <0, normal; 1, restart>
BS1 [2] <0, normal; 1, lost>
BS1 [3] <0, normal; 1, forced>
BS1 [4] <0, normal; 1, forced>
BS1 [4] <0, normal; 1, roll-over>
BS1 [5] <0, normal; 1, roll-over>
BS1 [6] <0>
BS1 [7] <0>
DNP Users Group
6.25 32-BIT COUNTER CHANGE EVENT WITH TIME
Data Object 22 - Variation: 05
Type: Event
Description:
The 32-bit counter change event with time represents a counter value that has exceeded a
configured deadband. This can be accumulated pulses or transitions from a hardware or
software point.
The value field shows the value of the counter which generated the event.
The Time field contains the time that processing generated the event.
The flag field has the same meaning as in previous objects.
DNP V3.00 Data Object Library (Version 0.02)
6-31
Object Coding:
FLAG
7
6
5
4
3
2
1
0
Value
31
0
Time
47
SQ4
0
{FLAG
Value
Time
}
=
=
=
BS8 [0..7]
UI32 [0..31] <0..232-1>
UI48 [0..47] <248 -1 ms>
FLAG
On-line
Restart
Communication lost
Remote forced data
Local forced data
Roll-over
Roll-over
Reserved
Reserved
}
={
=
=
=
=
=
=
=
=
=
BS1 [0] <0, off-line; 1, on-line>
BS1 [1] <0, normal; 1, restart>
BS1 [2] <0, normal; 1, lost>
BS1 [3] <0, normal; 1, forced>
BS1 [4] <0, normal; 1, forced>
BS1 [4] <0, normal; 1, roll-over>
BS1 [5] <0, normal; 1, roll-over>
BS1 [6] <0>
BS1 [7] <0>
Narrative:
Time is recorded as milliseconds since midnight, January 1st, 1970, at zero hours, zero
minutes, seconds, and milliseconds.
6-32
DNP Users Group
6.26 16-BIT COUNTER CHANGE EVENT WITH TIME
Data Object 22 - Variation: 06
Type: Event
Description:
The 16-bit counter change event with time represents a counter value that has exceeded a
configured deadband. This can be accumulated pulses or transitions from a hardware or
software point.
The value field shows the value of the counter which generated the event.
The time field contains the time that processing generated the event.
The flag field has the same meaning as in previous objects.
DNP V3.00 Data Object Library (Version 0.02)
6-33
Object Coding:
FLAG
7
6
5
4
3
2
1
0
Value
15
0
Time
47
SQ4
0
{FLAG
Value
Time
}
=
=
=
BS8 [0..7]
UI16 [0..15] <0..216-1>
UI48 [0..47] <248 -1 ms>
FLAG
On-line
Restart
Communication lost
Remote forced data
Local forced data
Roll-over
Roll-over
Reserved
Reserved
}
={
=
=
=
=
=
=
=
=
=
BS1 [0] <0, off-line; 1, on-line>
BS1 [1] <0, normal; 1, restart>
BS1 [2] <0, normal; 1, lost>
BS1 [3] <0, normal; 1, forced>
BS1 [4] <0, normal; 1, forced>
BS1 [4] <0, normal; 1, roll-over>
BS1 [5] <0, normal; 1, roll-over>
BS1 [6] <0>
BS1 [7] <0>
Narrative:
Time is recorded as milliseconds since midnight, January 1st, 1970, at zero hours, zero
minutes, seconds, and milliseconds.
6-34
DNP Users Group
6.27 32-BIT DELTA COUNTER CHANGE EVENT WITH TIME
Data Object 22 - Variation: 07
Type: Event
Description:
The 32-bit delta counter change event with time represents a delta counter value that has
exceeded a configured deadband. This can be accumulated pulses or transitions from a
hardware or software point.
The value field shows the value of the change which generated the event.
The time contains the time that processing generated the event.
The flag field has the same meaning as in previous objects.
DNP V3.00 Data Object Library (Version 0.02)
6-35
Object Coding:
FLAG
7
6
5
4
3
2
1
0
Value
31
0
Time
47
SQ4
0
{FLAG
Value
Time
}
=
=
=
BS8 [0..7]
UI32 [0..31] <0..232-1>
UI48 [0..47] <248 -1 ms>
FLAG
On-line
Restart
Communication lost
Remote forced data
Local forced data
Roll-over
Roll-over
Reserved
Reserved
}
={
=
=
=
=
=
=
=
=
=
BS1 [0] <0, off-line; 1, on-line>
BS1 [1] <0, normal; 1, restart>
BS1 [2] <0, normal; 1, lost>
BS1 [3] <0, normal; 1, forced>
BS1 [4] <0, normal; 1, forced>
BS1 [4] <0, normal; 1, roll-over>
BS1 [5] <0, normal; 1, roll-over>
BS1 [6] <0>
BS1 [7] <0>
Narrative:
Time is recorded as milliseconds since midnight, January 1st, 1970, at zero hours, zero
minutes, seconds, and milliseconds.
6-36
DNP Users Group
6.28 16-BIT DELTA COUNTER CHANGE EVENT WITH TIME
Data Object 22 - Variation: 08
Type: Event
Description:
The 16-bit delta counter change event with time represents a delta counter value that has
exceeded a configured deadband. This can be accumulated pulses or transitions from a
hardware or software point.
The value field shows the value of the change which generated the event.
The time field contains the time that processing generated the event.
The flag field has the same meaning as in previous objects.
DNP V3.00 Data Object Library (Version 0.02)
6-37
Object Coding:
FLAG
7
6
5
4
3
2
1
0
Value
15
0
Time
47
SQ4
0
{FLAG
Value
Time
}
=
=
=
BS8 [0..7]
UI16 [0..15] <0..216-1>
UI48 [0..47] <248 -1 ms>
FLAG
On-line
Restart
Communication lost
Remote forced data
Local forced data
Roll-over
Roll-over
Reserved
Reserved
}
={
=
=
=
=
=
=
=
=
=
BS1 [0] <0, off-line; 1, on-line>
BS1 [1] <0, normal; 1, restart>
BS1 [2] <0, normal; 1, lost>
BS1 [3] <0, normal; 1, forced>
BS1 [4] <0, normal; 1, forced>
BS1 [4] <0, normal; 1, roll-over>
BS1 [5] <0, normal; 1, roll-over>
BS1 [6] <0>
BS1 [7] <0>
Narrative:
Time is recorded as milliseconds since midnight, January 1st, 1970, at zero hours, zero
minutes, seconds, and milliseconds.
6-38
DNP Users Group
6.29 32-BIT COUNTER CHANGE EVENT WITHOUT TIME
Data Object 23 - Variation: 01
Type: Frozen Event
Description:
The 32-bit frozen counter event without time object represents a frozen counter value that is
reported as an event. This can be accumulated pulses or transitions from a hardware or
software point.
The frozen value field shows the value at the time of freezing.
The flag field has the same meaning as in previous objects.
Object Coding:
FLAG
7
6
5
4
3
2
1
0
Frozen value
31
SQ4
0
{FLAG
Frozen value
}
=
=
BS8 [0..7]
UI32 [0..31] <0..232-1>
FLAG
On-line
Restart
Communication lost
Remote forced data
Local forced data
Roll-over
Roll-over
Reserved
Reserved
}
={
=
=
=
=
=
=
=
=
=
BS1 [0] <0, off-line; 1, on-line>
BS1 [1] <0, normal; 1, restart>
BS1 [2] <0, normal; 1, lost>
BS1 [3] <0, normal; 1, forced>
BS1 [4] <0, normal; 1, forced>
BS1 [4] <0, normal; 1, roll-over>
BS1 [5] <0, normal; 1, roll-over>
BS1 [6] <0>
BS1 [7] <0>
DNP V3.00 Data Object Library (Version 0.02)
6-39
6.30 16-BIT FROZEN COUNTER EVENT WITHOUT TIME
Data Object 23 - Variation: 02
Type: Frozen Event
Description:
The 16-bit frozen counter event without time represents a frozen counter value that is
reported as an event. This can be accumulated pulses or transitions from a hardware or
software point.
The frozen value field shows the value at the time of freezing.
The flag field has the same meaning as in previous objects.
Object Coding:
FLAG
7
6
5
4
3
2
1
0
Frozen value
15
SQ4
6-40
0
{FLAG
Frozen value
}
=
=
BS8 [0..7]
UI16 [0..15] <0..216-1>
FLAG
On-line
Restart
Communication lost
Remote forced data
Local forced data
Roll-over
Roll-over
Reserved
Reserved
}
={
=
=
=
=
=
=
=
=
=
BS1 [0] <0, off-line; 1, on-line>
BS1 [1] <0, normal; 1, restart>
BS1 [2] <0, normal; 1, lost>
BS1 [3] <0, normal; 1, forced>
BS1 [4] <0, normal; 1, forced>
BS1 [4] <0, normal; 1, roll-over>
BS1 [5] <0, normal; 1, roll-over>
BS1 [6] <0>
BS1 [7] <0>
DNP Users Group
6.31 32-BIT FROZEN DELTA COUNTER EVENT WITHOUT TIME
Data Object 23 - Variation: 03
Type: Frozen Event
Description:
The 32-bit frozen delta counter event without time represents a frozen delta counter value
that is reported as an event. This can be accumulated pulses or transitions from a hardware
or software point.
The frozen delta value field shows the change in counter value at the time of freezing.
The flag field has the same meaning as in previous objects.
Object Coding:
FLAG
7
6
5
4
3
2
1
0
Frozen delta value
31
SQ4
0
{FLAG
Frozen delta value
}
=
=
BS8 [0..7]
UI32 [0..31] <0..232-1>
FLAG
On-line
Restart
Communication lost
Remote forced data
Local forced data
Roll-over
Roll-over
Reserved
Reserved
}
={
=
=
=
=
=
=
=
=
=
BS1 [0] <0, off-line; 1, on-line>
BS1 [1] <0, normal; 1, restart>
BS1 [2] <0, normal; 1, lost>
BS1 [3] <0, normal; 1, forced>
BS1 [4] <0, normal; 1, forced>
BS1 [4] <0, normal; 1, roll-over>
BS1 [5] <0, normal; 1, roll-over>
BS1 [6] <0>
BS1 [7] <0>
DNP V3.00 Data Object Library (Version 0.02)
6-41
6.32 16-BIT FROZEN DELTA COUNTER WITHOUT TIME
Data Object 23 - Variation: 04
Type: Frozen Event
Description:
The 16-bit frozen delta counter event without time represents a frozen delta counter value
that is reported as an event. This can be accumulated pulses or transitions from a hardware
or software point.
The frozen delta value field shows the change in counter value at the time of freezing.
The flag field has the same meaning as in previous objects.
Object Coding:
FLAG
7
6
5
4
3
2
1
0
Frozen delta value
15
SQ4
6-42
0
{FLAG
Frozen delta value
}
=
=
BS8 [0..7]
UI16 [0..15] <0..216-1>
FLAG
On-line
Restart
Communication lost
Remote forced data
Local forced data
Roll-over
Roll-over
Reserved
Reserved
}
={
=
=
=
=
=
=
=
=
=
BS1 [0] <0, off-line; 1, on-line>
BS1 [1] <0, normal; 1, restart>
BS1 [2] <0, normal; 1, lost>
BS1 [3] <0, normal; 1, forced>
BS1 [4] <0, normal; 1, forced>
BS1 [4] <0, normal; 1, roll-over>
BS1 [5] <0, normal; 1, roll-over>
BS1 [6] <0>
BS1 [7] <0>
DNP Users Group
6.33 32-BIT FROZEN COUNTER EVENT WITH TIME
Data Object 23 - Variation: 05
Type: Frozen Event
Description:
The 32-bit frozen counter event with time represents a frozen counter value that is reported
as an event. This can be accumulated pulses or transitions from a hardware or software
point.
The frozen value shows the value of the counter at time of freeze.
The time of freeze contains the time that the object was frozen.
The flag field has the same meaning as in previous objects.
DNP V3.00 Data Object Library (Version 0.02)
6-43
Object Coding:
FLAG
7
6
5
4
3
2
1
0
Frozen Value
31
0
Time of Freeze
47
SQ4
0
{FLAG
Frozen Value
Time of Freeze
}
=
=
=
BS8 [0..7]
UI32 [0..31] <0..232-1>
UI48 [0..47] <248 -1 ms>
FLAG
On-line
Restart
Communication lost
Remote forced data
Local forced data
Roll-over
Roll-over
Reserved
Reserved
}
={
=
=
=
=
=
=
=
=
=
BS1 [0] <0, off-line; 1, on-line>
BS1 [1] <0, normal; 1, restart>
BS1 [2] <0, normal; 1, lost>
BS1 [3] <0, normal; 1, forced>
BS1 [4] <0, normal; 1, forced>
BS1 [4] <0, normal; 1, roll-over>
BS1 [5] <0, normal; 1, roll-over>
BS1 [6] <0>
BS1 [7] <0>
Narrative:
Time is recorded as milliseconds since midnight, January 1st, 1970, at zero hours, zero
minutes, seconds, and milliseconds.
6-44
DNP Users Group
6.34 16-BIT FROZEN COUNTER EVENT WITH TIME
Data Object 23 - Variation: 06
Type: Frozen Event
Description:
The 16-bit frozen counter event with time represents a frozen counter value that is reported
as an event. This can be accumulated pulses or transitions from a hardware or software
point.
The frozen value shows the value of the counter at time of freeze.
The time of freeze contains the time that the object was frozen.
The flag field has the same meaning as in previous objects.
DNP V3.00 Data Object Library (Version 0.02)
6-45
Object Coding:
FLAG
7
6
5
4
3
2
1
0
Frozen Value
15
0
Time of Freeze
47
SQ4
0
{FLAG
Frozen Value
Time of Freeze
}
=
=
=
BS8 [0..7]
UI16 [0..15] <0..216-1>
UI48 [0..47] <248 -1 ms>
FLAG
On-line
Restart
Communication lost
Remote forced data
Local forced data
Roll-over
Roll-over
Reserved
Reserved
}
={
=
=
=
=
=
=
=
=
=
BS1 [0] <0, off-line; 1, on-line>
BS1 [1] <0, normal; 1, restart>
BS1 [2] <0, normal; 1, lost>
BS1 [3] <0, normal; 1, forced>
BS1 [4] <0, normal; 1, forced>
BS1 [4] <0, normal; 1, roll-over>
BS1 [5] <0, normal; 1, roll-over>
BS1 [6] <0>
BS1 [7] <0>
Narrative:
Time is recorded as milliseconds since midnight, January 1st, 1970 at zero hours, zero
minutes, seconds and milliseconds.
6-46
DNP Users Group
6.35 32-BIT FROZEN DELTA COUNTER EVENT WITH TIME
Data Object 23 - Variation: 07
Type: Frozen Event
Description:
The 32-bit frozen delta counter event with time represents a frozen delta counter value that
is reported as an event. This can be accumulated pulses or transitions from a hardware or
software point.
The frozen value shows the change in the counter at time of freeze.
The time of freeze contains the time that the object was frozen.
The flag field has the same meaning as in previous objects.
DNP V3.00 Data Object Library (Version 0.02)
6-47
Object Coding:
FLAG
7
6
5
4
3
2
1
0
Frozen Value
31
0
Time of Freeze
47
SQ4
0
{FLAG
Frozen Value
Time of Freeze
}
=
=
=
BS8 [0..7]
UI32 [0..31] <0..232-1>
UI48 [0..47] <248 -1 ms>
FLAG
On-line
Restart
Communication lost
Remote forced data
Local forced data
Roll-over
Roll-over
Reserved
Reserved
}
={
=
=
=
=
=
=
=
=
=
BS1 [0] <0, off-line; 1, on-line>
BS1 [1] <0, normal; 1, restart>
BS1 [2] <0, normal; 1, lost>
BS1 [3] <0, normal; 1, forced>
BS1 [4] <0, normal; 1, forced>
BS1 [4] <0, normal; 1, roll-over>
BS1 [5] <0, normal; 1, roll-over>
BS1 [6] <0>
BS1 [7] <0>
Narrative:
Time is recorded as milliseconds since midnight, January 1st, 1970 at zero hours, zero
minutes, seconds and milliseconds.
6-48
DNP Users Group
6.36 16-BIT FROZEN DELTA COUNTER EVENT WITH TIME
Data Object 23 - Variation: 08
Type: Frozen Event
Description:
The 16-bit frozen delta counter event with time represents a frozen delta counter value that
is reported as an event. This can be accumulated pulses or transitions from a hardware or
software point.
The frozen value shows the change in the counter at time of freeze.
The time of freeze contains the time that the object was frozen.
The flag field has the same meaning as in previous objects.
DNP V3.00 Data Object Library (Version 0.02)
6-49
Object Coding:
FLAG
7
6
5
4
3
2
1
0
Frozen Value
15
0
Time of Freeze
47
SQ4
0
{FLAG
Frozen Value
Time of Freeze
}
=
=
=
BS8 [0..7]
UI16 [0..15] <0..216-1>
UI48 [0..47] <248 -1 ms>
FLAG
On-line
Restart
Communication lost
Remote forced data
Local forced data
Roll-over
Roll-over
Reserved
Reserved
}
={
=
=
=
=
=
=
=
=
=
BS1 [0] <0, off-line; 1, on-line>
BS1 [1] <0, normal; 1, restart>
BS1 [2] <0, normal; 1, lost>
BS1 [3] <0, normal; 1, forced>
BS1 [4] <0, normal; 1, forced>
BS1 [4] <0, normal; 1, roll-over>
BS1 [5] <0, normal; 1, roll-over>
BS1 [6] <0>
BS1 [7] <0>
Narrative:
Time is recorded as milliseconds since midnight, January 1st, 1970, at zero hours, zero
minutes, seconds, and milliseconds.
6-50
DNP Users Group
7. ANALOG INPUT OBJECT
DEFINITIONS
This section defines the analog input data objects using the rules established in section 2.
DECLARATION RULES FOR INFORMATION ELEMENTS.
7.1 32-BIT ANALOG INPUT
Data Object 30 - Variation: 01
Type: Static
Description:
The 32-bit Analog Input is an information object used to represent a hardware or software
analog point. The 32-bit signed value could represent a digitized signal or calculated value.
The Value field shows the current value of the analog input at the time of reporting or the
last reported value from the originating device.
The flag field has the same meaning as previous objects, with these additions:
•
The out of range field indicates that the digitized signal or calculation has exceeded +231
-1 positively, or -231 negatively. The actual value will be +231 -1 or -231 if it is overrange or under-range.
•
The reference check field indicates that the reference signal used to digitize the analog
input is not stable and the resulting digitized value may not be correct.
DNP V3.00 Data Object Library (Version 0.02)
7-1
Object Coding:
FLAG
7
0
Current value
31
SQ2
7-2
0
{FLAG
Current value
}
=
=
BS8 [0..7]
I32 [0..31] <231-1..-231>
FLAG
On-line
Restart
Communication lost
Remote forced data
Local forced data
Over-range
Reference check
Reserved
}
={
=
=
=
=
=
=
=
=
BS1 [0] <0, off-line; 1, on-line>
BS1 [1] <0, normal; 1, restart>
BS1 [2] <0, normal; 1, lost>
BS1 [3] <0, normal; 1, forced>
BS1 [4] <0, normal; 1, forced>
BS1 [5] <0, normal; 1, over-range>
BS1 [6] <0, normal; 1, error>
BS1 [7] <0>
DNP Users Group
7.2 16-BIT ANALOG INPUT
Data Object 30 - Variation: 02
Type: Static
Description:
The 16-bit analog input is an information object used to represent a hardware or software
analog point. The 16-bit signed value could represent a digitized signal or calculated value.
The value field shows the current value of the analog input at the time of reporting, or the
last reported value from the originating device.
The flag field has the same meaning as previous objects, with these additions:
• The over-range field indicates that the digitized signal or calculation has exceeded +215 1 positively, or -215 negatively. The actual value field can be ignored as its value is not
defined.
• The reference check field indicates that the reference signal used to digitize the analog
input is not stable and the resulting digitized value may not be correct.
DNP V3.00 Data Object Library (Version 0.02)
7-3
Object Coding:
FLAG
7
0
Current value
15
SQ2
7-4
0
{FLAG
Current value
}
=
=
BS8 [0..7]
I16 [0..15] <215-1..-215>
FLAG
On-line
Restart
Communication lost
Remote forced data
Local forced data
Over-range
Reference check
Reserved
}
={
=
=
=
=
=
=
=
=
BS1 [0] <0, off-line; 1, on-line>
BS1 [1] <0, normal; 1, restart>
BS1 [2] <0, normal; 1, lost>
BS1 [3] <0, normal; 1, forced>
BS1 [4] <0, normal; 1, forced>
BS1 [5] <0, normal; 1, over-range>
BS1 [6] <0, normal; 1, error>
BS1 [7] <0>
DNP Users Group
7.3 32-BIT ANALOG INPUT WITHOUT FLAG
Data Object 30 - Variation: 03
Type: Static
Description:
The 32-bit analog input is an information object used to represent a hardware or software
analog point. The 32-bit signed value could represent a digitized signal or calculated value.
The value field shows the current value of the analog input at the time of reporting, or the
last reported value from the originating device.
Object Coding:
Current value
31
SQ2
{Current value =
}
NOTE:
0
I32 [0..31] <231-1..-231>
The use of this variation implies that the input point is on-line and that all
other flag bits are normal (i.e. this variation implies that flag = 1).
DNP V3.00 Data Object Library (Version 0.02)
7-5
7.4 16-BIT ANALOG INPUT WITHOUT FLAG
Data Object 30 - Variation: 04
Type: Static
Description:
The 16-bit analog input is an information object used to represent a hardware or software
analog point. The 16-bit signed value could represent a digitized signal or calculated value.
The current value field shows the current value of the analog input at the time of reporting,
or the last reported value from the originating device.
Object Coding:
Current value
15
SQ2
{Current value =
}
NOTE:
7-6
0
I16 [0..15] <215-1..-215>
The use of this variation implies that the input point is on-line and that all
other flag bits are normal (i.e. this variation implies that flag = 1).
DNP Users Group
7.5 32-BIT FROZEN ANALOG INPUT
Data Object 31 - Variation: 01
Type: Frozen Static
Description:
The 32-bit frozen analog input is an information object used to represent a frozen hardware
or software analog point. The 32-bit signed value could represent a digitized signal or
calculated value.
The frozen value shows the value of the analog input at the time the last freeze command
was performed on this point.
The flag field has the same meaning as previous objects, with these additions:
• The over-range field indicates that the digitized signal or calculation has exceeded +231 1 positively, or -231 negatively. The actual value field can be ignored as its value is not
defined.
• The reference check field indicates that the reference signal used to digitize the analog
input is not stable, and the resulting digitized value may not be correct.
Object Coding:
FLAG
7
0
Frozen value
31
SQ2
0
{FLAG
Current value
}
=
=
BS8 [0..7]
I32 [0..31] <231-1..-231>
FLAG
On-line
Restart
Communication lost
Remote forced data
Local forced data
Over-range
Reference check
Reserved
}
={
=
=
=
=
=
=
=
=
BS1 [0] <0, off-line; 1, on-line>
BS1 [1] <0, normal; 1, restart>
BS1 [2] <0, normal; 1, lost>
BS1 [3] <0, normal; 1, forced>
BS1 [4] <0, normal; 1, forced>
BS1 [5] <0, normal; 1, over-range>
BS1 [6] <0, normal; 1, error>
BS1 [7] <0>
DNP V3.00 Data Object Library (Version 0.02)
7-7
7.6 16-BIT FROZEN ANALOG INPUT
Data Object 31 - Variation: 02
Type: Frozen Static
Description:
The 16-bit frozen analog input is an information object used to represent a frozen hardware
or software analog point. The 16-bit signed value could represent a digitized signal or
calculated value.
The frozen value shows the value of the analog input at the time the last freeze command
was performed on this point.
The flag field has the same meaning as previous objects, with these additions:
• The over-range field indicates that the digitized signal or calculation has exceeded +215 1 positively, or -215 negatively. The actual value field can be ignored as its value is not
defined.
• The reference check field indicates that the reference signal used to digitize the analog
input is not stable, and the resulting digitized value may not be correct.
Object Coding:
FLAG
7
0
Frozen value
15
SQ2
7-8
0
{FLAG
Current value
}
=
=
BS8 [0..7]
I16 [0..15] <215-1..-215>
FLAG
On-line
Restart
Communication lost
Remote forced data
Local forced data
Over-range
Reference check
Reserved
}
={
=
=
=
=
=
=
=
=
BS1 [0] <0, off-line; 1, on-line>
BS1 [1] <0, normal; 1, restart>
BS1 [2] <0, normal; 1, lost>
BS1 [3] <0, normal; 1, forced>
BS1 [4] <0, normal; 1, forced>
BS1 [5] <0, normal; 1, over-range>
BS1 [6] <0, normal; 1, error>
BS1 [7] <0>
DNP Users Group
7.7 32-BIT FROZEN ANALOG INPUT WITH TIME OF FREEZE
Data Object 31 - Variation: 03
Type: Frozen Static
Description:
The 32-bit frozen analog input with time of freeze is an information object used to represent
a frozen hardware or software analog point. The 32-bit signed value could represent a
digitized signal or calculated value.
The frozen value shows the value of the analog input at the time specified in time of freeze.
The time of freeze field shows the time at which the frozen value was equal to the current
value of the analog input. These values are equated on reception of a freeze analog
command.
The flag field has the same meaning as previous objects, with these additions:
• The over-range field indicates that the digitized signal or calculation has exceeded +231 1 positively, or -231 negatively. The actual value field can be ignored as its value is not
defined.
• The reference check field indicates that the reference signal used to digitize the analog
input is not stable and the resulting digitized value may not be correct.
DNP V3.00 Data Object Library (Version 0.02)
7-9
Object Coding:
FLAG
7
0
Frozen value
31
0
Time of Freeze
47
SQ2
7-10
0
{FLAG
Current value
Time of Freeze
}
=
=
=
BS8 [0..7]
I32 [0..31] <231-1..-231>
UI48[0..47] <0 .. 2 48 >
FLAG
On-line
Restart
Communication lost
Remote forced data
Local forced data
Over-range
Reference check
Reserved
}
={
=
=
=
=
=
=
=
=
BS1 [0] <0, off-line; 1, on-line>
BS1 [1] <0, normal; 1, restart>
BS1 [2] <0, normal; 1, lost>
BS1 [3] <0, normal; 1, forced>
BS1 [4] <0, normal; 1, forced>
BS1 [5] <0, normal; 1, over-range>
BS1 [6] <0, normal; 1, error>
BS1 [7] <0>
DNP Users Group
7.8 16-BIT FROZEN ANALOG INPUT WITH TIME OF FREEZE
Data Object 31 - Variation: 04
Type: Frozen Static
Description:
The 16-bit frozen analog input with time of freeze is an information object used to
represent a frozen hardware or software analog point. The 16-bit signed value could
represent a digitized signal or calculated value.
The frozen value shows the value of the analog input at the time specified in time of
freeze.
The time of freeze field shows the time at which the frozen value was equal to the current
value of the analog input. These values are equated on reception of a freeze analog
command.
The flag field has the same meaning as previous objects, with these additions:
• The over-range field indicates that the digitized signal or calculation has exceeded
+215 -1 positively, or -215 negatively. The actual value field can be ignored as its value
is not defined.
• The reference check field indicates that the reference signal used to digitize the analog
input is not stable, and the resulting digitized value may not be correct.
DNP V3.00 Data Object Library (Version 0.02)
7-11
Object Coding:
FLAG
7
0
Frozen value
15
0
Time of Freeze
47
SQ2
7-12
0
{FLAG
Time of freeze
Current value
}
=
=
=
BS8 [0..7]
UI48[0..47] <0 .. 2 48 -1>
I16 [0..15] <215-1..-215>
FLAG
On-line
Restart
Communication lost
Remote forced data
Local forced data
Over-range
Reference check
Reserved
}
={
=
=
=
=
=
=
=
=
BS1 [0] <0, off-line; 1, on-line>
BS1 [1] <0, normal; 1, restart>
BS1 [2] <0, normal; 1, lost>
BS1 [3] <0, normal; 1, forced>
BS1 [4] <0, normal; 1, forced>
BS1 [5] <0, normal; 1, over-range>
BS1 [6] <0, normal; 1, error>
BS1 [7] <0>
DNP Users Group
7.9 32-BIT FROZEN ANALOG INPUT WITHOUT FLAG
Data Object 31 - Variation: 05
Type: Frozen Static
Description:
The 32-bit frozen analog input is an information object used to represent a frozen
hardware or software analog point. The 32-bit signed value could represent a digitized
signal or calculated value.
The frozen value shows the value of the analog input at the time the last freeze command
was performed on this point.
Object Coding:
Frozen value
31
SQ2
{Current value=
}
NOTE:
0
I32 [0..31] <231-1..-231>
The use of this variation implies that the input point is on-line and that all
other flag bits are normal (i.e. this variation implies that flag = 1).
DNP V3.00 Data Object Library (Version 0.02)
7-13
7.10 16-BIT FROZEN ANALOG INPUT WITHOUT FLAG
Data Object 31 - Variation: 06
Type: Frozen Static
Description:
The 16-bit frozen analog input is an information object used to represent a frozen
hardware or software analog point. The 16-bit signed value could represent a digitized
signal or calculated value.
The frozen value shows the value of the analog input at the time the last freeze command
was performed on this point.
Object Coding:
Frozen value
15
SQ2
7-14
{Current value=
}
0
I16 [0..15] <215-1..-215>
DNP Users Group
7.11 32-BIT ANALOG CHANGE EVENT WITHOUT TIME
Data Object 32 - Variation: 01
Type: Event
Description:
The 32-bit analog change event without time is an information object used to represent a
changed hardware or software analog point. The 32-bit signed value could represent a
digitized signal or calculated value.
The current value field shows the current value of the analog input at the time of
reporting, or the last reported value from the originating device. This object will only be
reported if the current value and the last reported value differ by a configurable deadband
value. This filtering is commonly known as deadbanding.
The flag field has the same meaning as previous objects, with these additions:
• The over-range field indicates that the digitized signal or calculation has exceeded
+231 -1 positively, or -231 negatively. The actual value field can be ignored as its value
is not defined.
• The reference check field indicates that the reference signal used to digitize the analog
input is not stable, and the resulting digitized value may not be correct.
DNP V3.00 Data Object Library (Version 0.02)
7-15
Object Coding:
FLAG
7
0
Current value
31
SQ2
7-16
0
{FLAG
Current value
}
=
=
BS8 [0..7]
I32 [0..31] <231-1..-231>
FLAG
On-line
Restart
Communication lost
Remote forced data
Local forced data
Over-range
Reference check
Reserved
}
={
=
=
=
=
=
=
=
=
BS1 [0] <0, off-line; 1, on-line>
BS1 [1] <0, normal; 1, restart>
BS1 [2] <0, normal; 1, lost>
BS1 [3] <0, normal; 1, forced>
BS1 [4] <0, normal; 1, forced>
BS1 [5] <0, normal; 1, over-range>
BS1 [6] <0, normal; 1, error>
BS1 [7] <0>
DNP Users Group
7.12 16-BIT CHANGE EVENT WITHOUT TIME
Data Object 32 - Variation: 02
Type: Event
Description:
The 16-bit analog change event without time is an information object used to represent a
changed hardware or software analog point. The 16-bit signed value could represent a
digitized signal or calculated value.
The current value field shows the current value of the analog input at the time of
reporting, or the last reported value from the originating device. This object will only be
reported if the current value and the last reported value differ by a configurable deadband
value. This filtering is commonly known as deadbanding.
The flag field has the same meaning as previous objects, with these additions:
• The over-range field indicates that the digitized signal or calculation has exceeded
+215 -1 positively, or -215 negatively. The actual value field can be ignored as its value
is not defined.
• The reference check field indicates that the reference signal used to digitize the analog
input is not stable, and the resulting digitized value may not be correct.
DNP V3.00 Data Object Library (Version 0.02)
7-17
Object Coding:
FLAG
7
0
Current value
15
SQ2
7-18
0
{FLAG
Current value
}
=
=
BS8 [0..7]
I16 [0..15] <215-1..-215>
FLAG
On-line
Restart
Communication lost
Remote forced data
Local forced data
Over-range
Reference check
Reserved
}
={
=
=
=
=
=
=
=
=
BS1 [0] <0, off-line; 1, on-line>
BS1 [1] <0, normal; 1, restart>
BS1 [2] <0, normal; 1, lost>
BS1 [3] <0, normal; 1, forced>
BS1 [4] <0, normal; 1, forced>
BS1 [5] <0, normal; 1, over-range>
BS1 [6] <0, normal; 1, error>
BS1 [7] <0>
DNP Users Group
7.13 32-BIT ANALOG CHANGE EVENT WITH TIME
Data Object 32 - Variation: 03
Type: Event
Description:
The 32-bit analog change event with time is an information object used to represent a
changed hardware or software analog point. The 32-bit signed value could represent a
digitized signal or calculated value.
The current value shows the value of the analog input at the time specified in time.
The time field shows the time at which the processing caused the event.
The flag field has the same meaning as previous objects, with these additions:
• The over-range field indicates that the digitized signal or calculation has exceeded
+231 -1 positively, or -231 negatively. The actual value field can be ignored as its value
is not defined.
• The reference check field indicates that the reference signal used to digitize the analog
input is not stable, and the resulting digitized value may not be correct.
DNP V3.00 Data Object Library (Version 0.02)
7-19
Object Coding:
FLAG
7
0
Value
31
0
Time
47
SQ2
7-20
0
{FLAG
Time
Value
}
=
=
=
BS8 [0..7]
UI48[0..47] <0 .. 2 48 -1>
I32[0..31] <231-1..-231>
FLAG
On-line
Restart
Communication lost
Remote forced data
Local forced data
Over-range
Reference check
Reserved
}
={
=
=
=
=
=
=
=
=
BS1 [0] <0, off-line; 1, on-line>
BS1 [1] <0, normal; 1, restart>
BS1 [2] <0, normal; 1, lost>
BS1 [3] <0, normal; 1, forced>
BS1 [4] <0, normal; 1, forced>
BS1 [5] <0, normal; 1, over-range>
BS1 [6] <0, normal; 1, error>
BS1 [7] <0>
DNP Users Group
7.14 16-BIT ANALOG CHANGE EVENT WITH TIME
Data Object 32 - Variation: 04
Type: Event
Description:
The 16-bit analog change event with time is an information object used to represent a
changed hardware or software analog point. The 16-bit signed value could represent a
digitized signal or calculated value.
The current value shows the value of the analog input at the time specified in time.
The time field shows the time at which the processing caused the event.
The flag field has the same meaning as previous objects, with these additions:
• The over-range field indicates that the digitized signal or calculation has exceeded
+215 -1 positively, or -215 negatively. The actual value field can be ignored as its value
is not defined.
• The reference check field indicates that the reference signal used to digitize the analog
input is not stable, and the resulting digitized value may not be correct.
DNP V3.00 Data Object Library (Version 0.02)
7-21
Object Coding:
FLAG
7
0
Value
15
0
Time
47
SQ2
7-22
0
{FLAG
Time
Value
}
=
=
=
BS8 [0..7]
UI48 [0..47] <0 .. 2 48 -1>
I16 [0..15] <215-1..-215>
FLAG
On-line
Restart
Communication lost
Remote forced data
Local forced data
Over-range
Reference check
Reserved
}
={
=
=
=
=
=
=
=
=
BS1 [0] <0, off-line; 1, on-line>
BS1 [1] <0, normal; 1, restart>
BS1 [2] <0, normal; 1, lost>
BS1 [3] <0, normal; 1, forced>
BS1 [4] <0, normal; 1, forced>
BS1 [5] <0, normal; 1, over-range>
BS1 [6] <0, normal; 1, error>
BS1 [7] <0>
DNP Users Group
7.15 32-BIT FROZEN ANALOG EVENT WITHOUT TIME
Data Object 33 - Variation: 01
Type: Frozen Event
Description:
The 32-bit frozen analog event without time is an information object used to represent a
frozen hardware or software analog point that is reported as an event. The 32-bit signed
value could represent a digitized signal or calculated value.
The frozen value field shows the value of the analog input at the time of freeze.
The flag field has the same meaning as previous objects, with these additions:
• The over-range field indicates that the digitized signal or calculation has exceeded
+231 -1 positively, or -231 negatively. The actual value field can be ignored as its value
is not defined.
• The reference check field indicates that the reference signal used to digitize the analog
input is not stable, and the resulting digitized value may not be correct.
DNP V3.00 Data Object Library (Version 0.02)
7-23
Object Coding:
FLAG
7
0
Frozen value
31
SQ2
7-24
0
{FLAG
Frozen value
}
=
=
BS8 [0..7]
I32 [0..31] <231-1..-231>
FLAG
On-line
Restart
Communication lost
Remote forced data
Local forced data
Over-range
Reference check
Reserved
}
={
=
=
=
=
=
=
=
=
BS1 [0] <0, off-line; 1, on-line>
BS1 [1] <0, normal; 1, restart>
BS1 [2] <0, normal; 1, lost>
BS1 [3] <0, normal; 1, forced>
BS1 [4] <0, normal; 1, forced>
BS1 [5] <0, normal; 1, over-range>
BS1 [6] <0, normal; 1, error>
BS1 [7] <0>
DNP Users Group
7.16 16-BIT FROZEN ANALOG EVENT WITHOUT TIME
Data Object 33 - Variation: 02
Type: Frozen Event
Description:
The 16-bit frozen analog event without time is an information object used to represent a
frozen hardware or software analog point that is reported as an event. The 16-bit signed
value could represent a digitized signal or calculated value.
The frozen value field shows the value of the analog input at the time of freeze.
The flag field has the same meaning as previous objects, with these additions:
• The over-range field indicates that the digitized signal or calculation has exceeded
+215 -1 positively, or -215 negatively. The actual value field can be ignored as its value
is not defined.
• The reference check field indicates that the reference signal used to digitize the analog
input is not stable, and the resulting digitized value may not be correct.
DNP V3.00 Data Object Library (Version 0.02)
7-25
Object Coding:
FLAG
7
0
Frozen value
15
SQ2
7-26
0
{FLAG
Frozen value
}
=
=
BS8 [0..7]
I16 [0..15] <215-1..-215>
FLAG
On-line
Restart
Communication lost
Remote forced data
Local forced data
Over-range
Reference check
Reserved
}
={
=
=
=
=
=
=
=
=
BS1 [0] <0, off-line; 1, on-line>
BS1 [1] <0, normal; 1, restart>
BS1 [2] <0, normal; 1, lost>
BS1 [3] <0, normal; 1, forced>
BS1 [4] <0, normal; 1, forced>
BS1 [5] <0, normal; 1, over-range>
BS1 [6] <0, normal; 1, error>
BS1 [7] <0>
DNP Users Group
7.17 32-BIT FROZEN ANALOG EVENT WITH TIME
Data Object 33 - Variation: 03
Type: Frozen Event
Description:
The 32-bit frozen analog event with time is an information object used to represent a
frozen hardware or software analog point that is reported as an event. The 32-bit signed
value could represent a digitized signal or calculated value.
The frozen value field shows the value of the analog input at the time of a freeze.
The flag field has the same meaning as previous objects, with these additions:
• The over-range field indicates that the digitized signal or calculation has exceeded
+231 -1 positively, or -231 negatively. The actual value field can be ignored as its value
is not defined.
• The reference check field indicates that the reference signal used to digitize the analog
input is not stable, and the resulting digitized value may not be correct.
• The time of freeze field shows the time at which the frozen value was equal to the
current value of the analog input. These values are equated on reception of a freeze
analog command.
DNP V3.00 Data Object Library (Version 0.02)
7-27
Object Coding:
FLAG
7
0
Frozen value
31
0
Time of Freeze
47
SQ2
7-28
0
{FLAG
Frozen value
Time of Freeze
}
=
=
=
BS8 [0..7]
I32 [0..31] <231-1..-231>
UI48[0..47] <0 .. 2 48 -1>
FLAG
On-line
Restart
Communication lost
Remote forced data
Local forced data
Over-range
Reference check
Reserved
}
={
=
=
=
=
=
=
=
=
BS1 [0] <0, off-line; 1, on-line>
BS1 [1] <0, normal; 1, restart>
BS1 [2] <0, normal; 1, lost>
BS1 [3] <0, normal; 1, forced>
BS1 [4] <0, normal; 1, forced>
BS1 [5] <0, normal; 1, over-range>
BS1 [6] <0, normal; 1, error>
BS1 [7] <0>
DNP Users Group
7.18 16-BIT FROZEN ANALOG EVENT WITH TIME
Data Object 33 - Variation: 04
Type: Frozen Event
Description:
The 16-bit frozen analog event with time is an information object used to represent a
frozen hardware or software analog point that is reported as an event. The 16-bit signed
value could represent a digitized signal or calculated value.
The frozen value field shows the value of the analog input at the time of a freeze.
The Flag field has the same meaning as previous objects with these additions:
• The over-range field indicates that the digitized signal or calculation has exceeded
+215 -1 positively, or -215 negatively. The actual value field can be ignored as its value
is not defined.
• The reference check field indicates that the reference signal used to digitize the analog
input is not stable, and the resulting digitized value may not be correct.
• The time of freeze field shows the time at which the frozen value was equal to the
current value of the analog input. These values are equated on reception of a freeze
analog command.
DNP V3.00 Data Object Library (Version 0.02)
7-29
Object Coding:
FLAG
7
0
Frozen value
15
0
Time of Freeze
47
SQ2
7-30
0
{FLAG
Frozen value
Time of Freeze
}
=
=
=
BS8 [0..7]
I16 [0..15] <215-1..-215>
UI48[0..47] <0 .. 2 48 -1>
FLAG
On-line
Restart
Communication lost
Remote forced data
Local forced data
Over-range
Reference check
Reserved
}
={
=
=
=
=
=
=
=
=
BS1 [0] <0, off-line; 1, on-line>
BS1 [1] <0, normal; 1, restart>
BS1 [2] <0, normal; 1, lost>
BS1 [3] <0, normal; 1, forced>
BS1 [4] <0, normal; 1, forced>
BS1 [5] <0, normal; 1, over-range>
BS1 [6] <0, normal; 1, error>
BS1 [7] <0>
DNP Users Group
8. ANALOG OUTPUT OBJECT
DEFINITIONS
This section defines the analog output data objects using the rules established in section
2. DECLARATION RULES FOR INFORMATION ELEMENTS.
8.1 32-BIT ANALOG OUTPUT STATUS
Data Object 40 - Variation: 01
Type: Static
Description:
The 32-bit analog output status information object represents the actual value of an
analog output or software point and associated status.
The actual value field contains the current value of the analog output.
The flag field has the same meaning as previous objects.
DNP V3.00 Data Object Library (Version 0.02)
8-1
Object Coding:
FLAG
7
6
5
4
3
2
1
0
Current value
31
SQ3
0
{FLAG
Current value
}
=
=
BS8 [0..7]
I32 [0..31] <231-1..-231>
FLAG
On-line
Restart
Communication lost
Remote forced data
Reserved
Reserved
Reserved
Reserved
}
={
=
=
=
=
=
=
=
=
BS1 [0] <0, off-line; 1, on-line>
BS1 [1] <0, normal; 1, restart>
BS1 [2] <0, normal; 1, lost>
BS1 [3] <0, unlock; 1, forced>
BS1 [4] <0>
BS1 [5] <0>
BS1 [6] <0>
BS1 [7] <0>
Narrative:
This object can be returned after an analog output operation is performed in order to
determine the success of the operation.
8-2
DNP Users Group
8.2 16-BIT ANALOG OUTPUT STATUS
Data Object 40 - Variation: 02
Type: Static
Description:
The 16-bit analog output status information object represents the actual value of a
hardware DAC analog output or software point and associated status.
The actual value field contains the current value of the analog output.
The flag field has the same meaning as previous objects.
Object Coding:
FLAG
7
6
5
4
3
2
1
0
Current value
15
SQ3
0
{FLAG
Current value
}
=
=
BS8 [0..7]
I16 [0..15] <215-1..-215>
FLAG
On-line
Restart
Communication lost
Remote forced data
Reserved
Reserved
Reserved
Reserved
}
={
=
=
=
=
=
=
=
=
BS1 [0] <0, off-line; 1, on-line>
BS1 [1] <0, normal; 1, restart>
BS1 [2] <0, normal; 1, lost>
BS1 [3] <0, unlock; 1, forced>
BS1 [4] <0>
BS1 [5] <0>
BS1 [6] <0>
BS1 [7] <0>
Narrative:
This object can be returned after an analog output operation is performed in order to
determine the success of the operation.
DNP V3.00 Data Object Library (Version 0.02)
8-3
8.3 32-BIT ANALOG OUTPUT BLOCK
Data Object 41 - Variation: 01
Type: Static
Description:
The 32-bit analog output information object represents the desired value of a hardware
DAC analog output or software point. The value represented is merely logical, as the
value may be scaled and/or manipulated before any output level is set.
The requested value field contains the desired value of the analog output. The actual
value of the analog output is returned in the analog output status object.
The control status field indicates the status of the analog control operation, in the same
way that the control delay output block does. The definition of this field is the same as the
control relay output block.
Object Coding:
Requested value
31
0
Control Status
7
0
I32 [0..31] <231-1..-231>
Requested value
=
Status
= I8 [0..7] <0..255>
This is used in a control request/response.
8-4
DNP Users Group
8.4 16-BIT ANALOG OUTPUT BLOCK
Data Object 41 - Variation: 02
Type: Static
Description:
The 16-bit analog output block information object represents the desired value of a
hardware DAC analog output or software point. The value represented is merely logical,
as the value may be scaled and/or manipulated before any output level is set.
The requested value field contains the desired value of the analog output. The actual
value of the analog output is returned in the analog output status object.
The control status field indicates the status of the analog control operation in the same
way as the control relay output block. The definition of this field is the same as the
control relay output block.
Object Coding:
Requested value
15
0
Control Status
7
I16
I8
Requested value
Status
0
=
=
I16 [0..15] <215-1..-215>
I8 [0..7] <0..255>
DNP V3.00 Data Object Library (Version 0.02)
8-5
8-6
DNP Users Group
9. TIME OBJECT DEFINITIONS
This section defines the time data objects using the rules established in section 2.
DECLARATION RULES FOR INFORMATION ELEMENTS.
9.1 TIME AND DATE
Data Object 50 - Variation: 01
Description:
The time and date object is an information object that represents the absolute time of day
and date. This object should be used for time-synchronization.
Object Coding:
Absolute Time
Absolute Time=
7
6
5
4
3
2
1
0
15
14
13
12
11
10
9
8
23
22
21
20
19
18
17
16
31
30
29
28
27
26
25
24
39
38
37
36
35
34
33
32
47
46
45
44
43
42
41
40
UI48 [0..47] <0..248-1, msec>
Narrative:
Absolute Time is recorded as milliseconds since midnight, January 1st, 1970, at zero
hours, zero minutes, zero seconds, and milliseconds.
DNP V3.00 Data Object Library (Version 0.02)
9-1
9.2 TIME AND DATE WITH INTERVAL
Data Object 50 - Variation: 02
Description:
The time and date with interval represents both an absolute time and an interval time. The
absolute time represents a starting time (or base time), and the interval time is a positive
offset from the base time. The interval could be applied several times to the base time in
order to specify a sequence of periodic times.
For example, this can be used to specify a sequence of times for periodic freezing of
objects.
The absolute time field specifies the base time. This time is the real time-of-day.
The interval field specifies the periodic interval or offset from the base time.
9-2
DNP Users Group
Object Coding:
Absolute time
7
6
5
4
3
2
1
0
15
14
13
12
11
10
9
8
23
22
21
20
19
18
17
16
31
30
29
28
27
26
25
24
39
38
37
36
35
34
33
32
47
46
45
44
43
42
41
40
Interval
SQ2
{Absolute time
Interval
}
7
6
5
4
3
2
1
0
15
14
13
12
11
10
9
8
23
22
21
20
19
18
17
16
31
30
29
28
27
26
25
24
=
=
UI48 [0..47] <0..248 -1, msec>
UI32 [0..31] <0..232-1, msec>
Narrative:
Absolute time is recorded as milliseconds since midnight, January 1st, 1970, at zero
hours, zero minutes, zero seconds, and milliseconds.
DNP V3.00 Data Object Library (Version 0.02)
9-3
9.3 TIME AND DATE CTO
Data Object 51 - Variation: 01
Description:
The time and date CTO (common time of occurrence) object is an information object that
represents the absolute time of day. This object should be used in conjunction with other
objects that contain time references. This object is a base time to which a relative
(incremental) time can be added, or from which it can be subtracted, in order to obtain
another absolute time reference.
Object Coding:
Absolute Time
Absolute time =
7
6
5
4
3
2
1
0
15
14
13
12
11
10
9
8
23
22
21
20
19
18
17
16
31
30
29
28
27
26
25
24
39
38
37
36
35
34
33
32
47
46
45
44
43
42
41
40
UI48 [0..47] <0..248-1, msec>
Narrative:
Absolute time is recorded as milliseconds since midnight, January 1st, 1970, at zero
hours, zero minutes, zero seconds, and milliseconds.
9-4
DNP Users Group
9.4 UN-SYNCHRONIZED TIME AND DATE CTO
Data Object 51 - Variation: 02
Description:
The un-synchronized time and date CTO object is an information object that represents
the relative-absolute time of day. This object should be used in conjunction with other
objects that contain time references. This object is a relative base time to which a relative
(incremental) time can be added, or from which it can be subtracted, in order to obtain
another relative-absolute time reference. The real absolute time can be calculated by the
message receiver, based on the reception time of the message containing this object. Any
objects that follow this object, and come before the next common-time object that
contains relative time, must be corrected using this relative-absolute time value.
Relative-absolute time is the un-synchronized time-of-day at the station sending this
object (i.e. the responding station).
Object Coding:
Relative Absolute Time
Relative-absolute time
7
6
5
4
3
2
1
0
15
14
13
12
11
10
9
8
23
22
21
20
19
18
17
16
31
30
29
28
27
26
25
24
39
38
37
36
35
34
33
32
47
46
45
44
43
42
41
40
=
UI48 [0..47] <0..248-1, msec>
Narrative:
Relative-absolute time is recorded as milliseconds since midnight, January 1st, 1970, at
zero hours, zero minutes, zero seconds, and milliseconds.
DNP V3.00 Data Object Library (Version 0.02)
9-5
9.5 TIME DELAY COARSE
Data Object 52 - Variation: 01
Description:
The time delay coarse information object represents a relative time that indicates a time
period starting from the time of message reception.
Object Coding:
Seconds
Seconds =
9-6
7
6
5
4
3
2
1
0
15
14
13
12
11
10
9
8
UI16 [0..15] <0..65,535, seconds>
DNP Users Group
9.6 TIME DELAY FINE
Data Object 52 - Variation: 02
Description:
The time delay fine information object represents a relative time that indicates a time
period starting from the time of message reception. This object can be used in timesynchronization to perform path delay measurement calculations or other functions that
require time-based calibration.
Object Coding:
Milliseconds
Milliseconds =
7
6
5
4
3
2
1
0
15
14
13
12
11
10
9
8
UI16 [0..15] <0..65,535, milliseconds>
DNP V3.00 Data Object Library (Version 0.02)
9-7
9-8
DNP Users Group
10. CLASS OBJECT DEFINITIONS
This section defines the class data objects using the rules established in section 2.
DECLARATION RULES FOR INFORMATION ELEMENTS.
10.1 CLASS 0 DATA
Data Object 60 - Variation: 01
Description:
The class 0 data object is an object place-holder that specifies a class of zero or more
information elements. These elements can be entire object types, a specific variation,
certain points of the variation, or any combination of these. The data specified by this
object type is configurable within the responding station.
Class 0 data is potentially any information object not assigned to class 1, 2, or 3. That is,
class 0 data is non-priority data.
Object Coding:
None.
Narrative:
The class 0 data object does not carry any information in itself, and therefore does not
have an object coding. Class 0 is a null class to which all data objects not assigned to
other classes can belong by default.
DNP V3.00 Data Object Library (Version 0.02)
10-1
10.2 CLASS 1 DATA
Data Object 60 - Variation: 02
Description:
The class 1 data object is an object place-holder that specifies a class of zero or more
information elements. These elements can be entire object types, a specific variation,
certain points of the variation, or any combination of these. The data specified by this
object type is configurable within the responding station.
The responding station does not send the class 1 data object, as it does not contain any
actual information, but is simply an identifier for other objects.
Object Coding:
None.
Narrative:
The class 1 data object is used to request a configured group, usually changes, of
information objects from a responding station. This data object does not carry any
information in itself, and therefore does not have an object coding.
Typically, class 1 data has higher priority than class 2, class 3, and class 0 data.
10-2
DNP Users Group
10.3 CLASS 2 DATA
Data Object 60 - Variation: 03
Description:
The class 2 data object is an object place-holder that specifies a class of zero or more
information elements. These elements can be entire object types, a specific variation,
certain points of the variation, or any combination of these. The data specified by this
object type is configurable within the responding station.
The responding station does not send the class 2 data object, as it does not contain any
actual information, but is simply an identifier for other objects.
Object Coding:
None.
Narrative:
The class 2 data object is used to request a configured group, usually changes, of
information objects from a responding station. This data object does not carry any
information in itself, and therefore does not have an object coding.
DNP V3.00 Data Object Library (Version 0.02)
10-3
10.4 CLASS 3 DATA
Data Object 60 - Variation: 04
Description:
The class 3 data object is an object place-holder that specifies a class of zero or more
information elements. These elements can be entire object types, a specific variation,
certain points of the variation, or any combination of these. The data specified by this
object type is configurable within the responding station.
The responding station does not send the class 3 data object, as it does not contain any
actual information, but is simply an identifier for other objects.
Object Coding:
None.
Narrative:
The class 3 data object is used to request a configured group, usually an event, of
information objects from a responding station. The data object does not carry any
information in itself, and therefore does not have an object coding.
10-4
DNP Users Group
11. FILE OBJECT DEFINITIONS
This section defines the file data objects using the rules established in section 2.
DECLARATION RULES FOR INFORMATION ELEMENTS.
11.1 FILE IDENTIFIER
Data Object 70 - Variation: 01
Description:
The file identifier object is an information object that represents information about a file
in a network file system. This object is intended to be used for transferring large blocks of
data that do not follow the format of an existing data object. In particular, this object is
suitable for uploading and downloading configuration files to remote devices or data
concentrators.
File operations are defined for this object to allow copying, deleting, etc. of a file. The
contents of the file object and the exact procedure to perform on the file will not be
interpreted by the Application Layer, and so must be performed by the user of the
Application Layer.
Networking Capability:
The File_Name field defines a logical name of a file or device. The receiving application
should interpret this name as a network file name. The root (or /) represents the root of
the host file system or receiving node. Sub-directories off of the root are interpreted as
branches off of the root. A branch can be a new directory, or more importantly, the
directory can be a remote file system which resides in a remote device that is accessible
from the current node.
When an application receives a file that specifies a directory or file that does not reside in
the current file system, the application must do whatever is necessary to obtain the file
from the specified device.
If the remote device is a DNP 3 device, then the following rules apply:
• On reception of a non-local file request, the application shall forward the request (in its
entirety) to the appropriate DNP 3 device.
DNP V3.00 Data Object Library (Version 0.02)
11-1
• The File_Name field will be modified so that the root of the remote device is specified
by the File_Name field. This means stripping off any paths that were used to actually
derive the name of the remote device.
For example, an IED configuration is sent from a host through two data concentrators
DC1 and DC2. The name from the Host to DC1 is:
\DC2\IED\config1
The name from the DC1 to DC2 is:
\IED\config1
The name from the DC2 to IED is:
\config1
In this case DC2 and IED were logical directories which specified remote devices and
config1 was the name of a physical file.
Object Coding:
This is not a fixed format object, but it is a variable format/sized object. This part of the
object is sent in a request.
31
24 23
Attributes
16 15
File_Type
End_Record
87
0
Name_Size
Start_Record
File_Size
Time_Of_Creation
Permission
File_ID
Owner_ID
Group_ID
Status
X
11-2
File_Name
File_Function
0
DNP Users Group
The File_Name field consists of 0 .. x bits where x = Name_Size * 8 and Name_Size = 0 ..
65535.
The file identifier object is sent in a DNP application request message to a remote device
using the Application Layer WRITE request function code. A device responds to a request
(or spontaneously reports) the file identifier object with an Application Layer RESPONSE
or UNSOLICITED RESPONSE function code (where appropriate).
File_Name:
Name of file to perform operation on. Consists of 1 or more of the
characters A .. Z, a..z, 0 .. 9, ".", "_", "\" and "-" ONLY, where " is
a delimiter, and where the hyphen cannot be used as the first
character of the file name. The size of this field is determined by
the Name_Size field below. The name can contain all path
information starting from the root (i.e. "\" of the file system. The
name can contain spaces ONLY to separate the file path/name
from program arguments.
Name_Size:
Number of characters in File_Name above.
File_Function:
Function to perform on specified records of file or on file system at
user layer. Includes the following: APPEND, DELETE, INSERT,
WRITE, ERASE, INFO, CWD, PWD, EXECUTE and READ. The
following values are defined:
0 = APPEND:
Add data records specified at END of file. The
Start_Record field indicates the number of records to
append to the file and also the number of data records
following the file identifier header in the message. The data
records that follow the header are described in the WRITE
function code (below). The device should respond with the
file identifier object with all available fields filled in, the
File_Function field set to RESPONSE, and the status field
set to the status of the requested operation.
1 = DELETE:
Remove the specified records from the file (i.e. file
shrinks). The Start_Record indicates the first record to
delete and the End_Record indicates the last record to
delete. There are no data records with this request. The
device should respond with the file identifier object with all
available fields filled in, the File_Function field set to
RESPONSE, and the status field set to the status of the
requested operation.
DNP V3.00 Data Object Library (Version 0.02)
11-3
2 = INSERT:
Insert these records at the place specified by the
Start_Record field and continuing to End_Record field (i.e.
the file grows in size). The number of data records
following the file identifier header in the message is
End_Record - Start_Record + 1. The data records that
follow the header are described in the WRITE function code
(below). The device should respond with the file identifier
object with all available fields filled in, the File_Function
field set to RESPONSE, and the status field set to the status
of the requested operation.
3 = WRITE:
Place these records at the place specified by Start_Record
field and continuing to End_Record field (i.e. the file can
potentially grow, and previous data is replaced by these
records). The number of data records following the file
identifier header in the message is End_Record Start_Record + 1. The data records that follow the header
are described below. The device should respond with the
file identifier object with all available fields filled in, the
File_Function field set to RESPONSE, and the status field
set to the status of the requested operation.
Data
x
Record_Size
0
15
Where:
4 = ERASE:
11-4
0
x = Record_Size * 8
Record_Size = 0 .. 65535
Clear (to NUL) or ERASE all records specified in Start and
End record fields (i.e. the file stays same size, BUT data is
cleared). There are no data records in this message. The
device should respond with the file identifier object with all
available fields filled in, the File_Function field set to
RESPONSE, and the status field set to the status of the
requested operation.
DNP Users Group
5 = INFO:
This request is used to obtain INFORMATION on the
specified file. The device should respond with the file
identifier object header with all fields filled in, the
File_Function set to RESPONSE and the status field set to
the status of the requested operation. The File_Name field
can be set to the special name "/" which indicates ALL
files. The device should respond with file identifier object
headers for each file in the device's file system. If the
device has only one file (and no directories) then this one
file's file identifier object header should be returned.
6 = CWD:
Change working directory (CWD) to path specified in
File_Name. The device should respond with the file
identifier object with all available fields filled in, the
File_Function field set to RESPONSE, the File_Name field
set to the new working directory, and the status field set to
the status of the requested operation.
7 = PWD:
Return the present working directory (PWD) in File_Name.
The device should respond with the file identifier object
with all available fields filled in, the File_Function field set
to RESPONSE, the File_Name field set to the current
working directory, and the status field set to the status of
the requested operation.
8 = EXEC:
Start or EXECUTE the application specified by File_Name
and pass it parameters that follow the file name portion of
File_Name (separated by spaces). The device should
respond with the file identifier object with all available
fields filled in, the File_Function field set to RESPONSE
and the status field set to the status of the requested
operation.
DNP V3.00 Data Object Library (Version 0.02)
11-5
9 = READ:
255 = RESP:
Read the specified records of file. The Start_Record
specifies the first record to READ, and the End_Record
specifies the last record to READ. If the Start_Record field
is 0, and the End_Record field is 65535, then the device
should respond with all available records. The File_Size
field in the response should indicate the total size of the
file. The device should respond with the file identifier
object with all available fields filled in, and all requested
data records (if possible), the File_Function field set to
RESPONSE, the Start_Record and End_Record should be
set to the beginning and end data records returned in the
response, and the status field set to the status of the
requested operation. The number of data records following
the file identifier header in the message is End_Record Start_Record + 1. The data records that follow the header
are described above under the WRITE function code.
This function code is used to indicate a response to a
request. The contents of this message are defined by the
function code in the request message.
Permission:
The permission field specifies the READ, WRITE, and EXECUTE
privileges for the file owner, the file owner's group and the world
(all others). The READ privilege gives the user the right to read the
file (READ, PWD, CWD, INFO request). The WRITE privilege
gives the user the right to change the file (APPEND, DELETE,
INSERT, WRITE, ERASE). The EXECUTE privilege gives the user
the right to run the specified application (EXEC request).
File_Type:
Indicates to a receiving application how to interpret the contents of
the file object. Valid types are: 8-bit binary, 8-bit ASCII, 7-bit
ASCII, EBCDIC, BCD, Baudot, International Baudot. The
following values are associated:
0 = 8-bit binary (un-coded octets of binary)
1 = 8-bit ASCII (extended ASCII characters)
2 = 7-bit ASCII (ASCII characters)
3 = EBCDIC (extended binary coded decimal)
4 = BCD (binary coded decimal)
5 = Baudot (5-bit Baudot)
6 = International Baudot (6-bit Baudot)
11-6
DNP Users Group
Attributes:
File attributes consisting of: regular, temporary, directory, or
FIFO. The following values are associated:
0:
Regular file is a real PERMANENT file.
1:
Temporary file is TEMPORARY and MUST be saved if changes are to be
kept.
2:
Directory is a file of files (cannot be read).
3:
FIFO is a first-in-first-out queue and can be used for inter-process
communication (analogous to a socket or pipe).
Status:
The status of the requested operation, consisting of: OK,
Doesn't_exist, Out_of_Space, No_Permission and File_Busy. The
following values are associated:
0:
OK indicates that the requested operation was successful.
1:
Doesn't_exist indicates that the file name is not contained in the file
system.
2:
Out_of_Space indicates that the file operation caused the file to exceed its
maximum size as determined by the User ID, Group ID, and Permission.
3:
No_Permission indicates that the file owner does not have enough
privileges for the operation requested.
4:
File_Busy indicates that the file could not be delivered to the destination.
File_Size:
Number of total bytes in file specified by File_Name.
Start_Record:
The start record number of file. A start record of 0 indicates the
start of the file, and a start record of 65535 indicates the last
record.
End_Record:
The end record number of file, similar to the Start_record. An end
record of 65535 combined with a start record of 0 in a READ
request indicates the entire file.
Record_Size:
Size in bytes of each individual data record excluding Record_Size
field.
Time_of_Creation:
Time that the file was created or last modified. This field has the
same format as Object 50 Variation 1.
DNP V3.00 Data Object Library (Version 0.02)
11-7
Owner_ID:
Unique identifier for the owner of the file.
Group_ID:
Unique identifier for the owner's group.
File_ID:
Unique integer identifier for the file. This field can also be used to
hold the error check (typically 16-bit CRC) for the file. In this case,
the File_ID is only unique when concatenated with the File_Name
and the Time_Of_Creation.
Data:
Actual data bytes that make up the file record. These 8-bit objects
are interpreted according to the File_Type field. The contents of
the Data field will not be interpreted by the DNP Application
Layer.
11-8
DNP Users Group
12. DEVICE OBJECT DEFINITIONS
This section defines the device data objects using the rules established in section 2.
DECLARATION RULES FOR INFORMATION ELEMENTS.
12.1 INTERNAL INDICATIONS
Data Object 80 - Variation: 01
Description:
The internal indications is an information element used to convey internal states and
diagnostic results of a responding station. This information can be used by a receiving
station to perform error recovery or other functions.
The number of internal indications objects sent in a message is device-dependent.
Object Coding:
0
BS1
[0..0]
State = BS1 [0] <0,1>
Narrative:
Transmission of the data object is always performed in complete octets, with unoccupied
bit positions set to zero. The following example illustrates the packing of n of these data
objects.
7
6
5
4
3
2
1
0
15
14
13
12
11
10
9
8
0
0
0
n
n-1
n-2
n-3
n-4
DNP V3.00 Data Object Library (Version 0.02)
12-1
12.2 STORAGE OBJECT
Data Object 81 - Variation: 01
Description:
The storage object is an information element used to convey the status of internal buffers
and storage areas for specific data types.
The group field indicates the group (or data type) that the status field corresponds to.
The variation field indicates the variation of the object that the status field corresponds
to.
The group and variation fields together specify the exact data type.
The status field shows what percentage of the buffer space allocated for this data type is
currently used up. The overflow bit indicates that the buffer space for the specified data
type has been over-utilized, and data objects have been lost.
12-2
DNP Users Group
Object Coding:
STATUS
7
6
5
4
3
2
1
0
GROUP
7
0
VARIATION
7
Storage Object
Status
0
={
Status
Group
Variation
}
=
=
=
BS8 [0..7]
UI8 [0..7] <0..255>
UI8 [0..7] <0..255>
={
Percent
Overflow
}
=
=
BS7 [0..6] <0..100>
BS1 [7] <0, 1; Overflow>
Narrative:
The storage object is used to indicate the status of buffer, queues, or other storage areas
within the sending device. The object is generated by the device as configured in the
device and described in the particular device profile.
DNP V3.00 Data Object Library (Version 0.02)
12-3
12.3 DEVICE PROFILE
Data Object 82 - Variation: 01
Description:
The device profile object provides for inter-operability between different DNP devices
which use only a sub-set of the DNP Application Layer function codes and data objects.
This object describes the station acting as a DNP master, and the valid function codes and
objects that the slave device supports. In addition, the range of indices for each
object/variation is also given so that configuration can be done on a dynamic basis.
Principle of operation:
The device profile object is intended to be sent by a slave device ONLY when the request
sent by the master is not recognizable, un-parsable, or objects referenced in the request
are not supported. Coincident with this message would be internal indications indicating
a problem with parsing.
Alternately, if the slave is configured in a quiescent environment, the slave could report
(spontaneously) the device profile object upon start-up.
The master, upon reception of this object, can change its polling scheme, poll request
message, limit or expand the assumed functionality of the slave, or re-configure the
master database with objects specified in this object.
If the master station is less sophisticated, the slave station can be marked off-line, and
manual re-configuration would be necessary to obtain proper communications again.
The device profile object consists of two sections. The first section, functions, specifies
the supported DNP Application Layer function codes. The second section, objects,
specifies the range of indices valid for each object/variation combination. Essentially, the
objects section is a sample master poll object header for each object/variation. It is
implied by the type of object what type of operation (function) can be performed on it so
there is no need to map each function code to a set of objects.
The functions field is an array of bits indicating support or non-support for each function
code. The bit positions 0 .. 63 correspond to DNP Application Layer function codes 0 to
63. For request function codes beyond 63, another functions field can follow the
ObjectHeaders.
The NumObjects field specifies how many sample object headers follow.
The ObjectHeader fields have the same form as a DNP Application Layer object header.
As a minimum, the header consists of the object, variation, qualifier, and 8-bit quantity.
This means that to describe most object variations, only four bytes are needed.
12-4
DNP Users Group
Object Coding:
Functions
63
0
NumObjects (n)
15
0
ObjectHeader 1
Quantity
7
Qualifier
0
7
Variation
0
7
Object
0
7
0
7
0
7
0
ObjectHeader 2
Quantity
7
Qualifier
0
7
Variation
0
7
Object
0
ObjectHeader n
Quantity
7
SQ2
Qualifier
0
7
{Functions
=
NumObjects =
}
Variation
0
7
Object
0
BS64 [0..63]
UI16 [0.15] <0..65535>
Each object header that follows has a variable format determined by the rules for
constructing Application Layer object headers.
Some sample headers are:
Object Header =
SQ4
{
Object
Variation
Qualifier
Quantity
}
=
=
=
=
UI8 [0..7] <0..255>
UI8 [0..7] <0..255>
UI8 [0..7] <0..255>
UI8 [0..7] <0..255>
DNP V3.00 Data Object Library (Version 0.02)
12-5
Object Header =
SQ5
{
Object
Variation
Qualifier
Start
Stop
}
Object Header =
SQ5
{
Object
Variation
Qualifier
Start
Stop
}
12-6
=
=
=
=
=
UI8 [0..7] <0..255>
UI8 [0..7] <0..255>
UI8 [0..7] <0..255>
UI8 [0..7] <0..255>
UI8 [0..7] <0..255>
=
=
=
=
=
UI8 [0..7] <0..255>
UI8 [0..7] <0..255>
UI8 [0..7] <0..255>
UI16 [0..15] <0..65535>
UI16 [0..15] <0..65535>
DNP Users Group
12.4 PRIVATE REGISTRATION OBJECT
Data Object 83 - Variation: 01
Type: Static\Event\Frozen Static\Frozen Event
Description:
This private registration object (PRO) object type is reserved for vendor-specific
definition. The object consists of a fixed header to provide for transparent data transfer,
and a unique registration number of the following object. The description of the contents
is entirely at the discretion of the vendor.
The Vendor field is a four-byte ASCII vendor name.
The Private Registration Number (PRN) field is a vendor designated object I.D.
The Len field contains the length of the Data Objects field in octets.
The Data Objects field contains the vendor's data (variable size and format) as described
by the PROD object.
Object Coding:
VENDOR
31
0
PRN
0
15
LEN
15
0
DATA OBJECTS
0
SQx
{Vendor
PRN
LEN
SQn
}
=
=
=
=
U132 [0..232-1]
U116[0..216-1]
U116 [0..216-1] Length of objects in <octets>
sequence of n basic DNP objects
DNP V3.00 Data Object Library (Version 0.02)
12-7
12.5 PRIVATE REGISTRATION OBJECT DESCRIPTOR
Data Object 83 - Variation: 02
Type: Static
Description:
This object type is reserved for vendor private registration object description. The object
is matched one-to-one with its PRO object. The object consists of a fixed header to
provide for transparent data transfer, and a unique registration number of the following
object. The description of the contents is entirely at the discretion of the vendor.
The private registration object description (PROD) object maintains a one-to-one
relationship with the PRO object, and can be used to parse the PRO into basic DNP
Objects for processing. The PROD consists of one element for each corresponding
element of the PRO. Each element consists in turn of a set of DNP object and variation
numbers.
The Vendor field is a four-byte ASCII vendor name.
The Private Registration Number (PRN) field is a vendor designated object I.D.
The Count field specifies the number of object definitions that follow this field. Each
object definition consists of the three fields: quantity, object and variation.
The Quantity field specifies the number of objects, specified by the object and variation
fields, which will be found in the PRO object.
12-8
DNP Users Group
Object Coding:
VENDOR
31
0
PRN
15
0
COUNT
15
0
QUANTITY
15
0
OBJECT
7
0
VARIATION
7
0
QUANTITY
15
0
OBJECT
7
0
VARIATION
7
0
QUANTITY
15
0
OBJECT
7
0
VARIATION
7
SQx
{Vendor
PRN
COUNT
SQn
0
=
=
=
=
{
UI32 [0..232-1]
UI16 [0..216-1]
UI16 [0..216-1]
Sequence of n basic DNP object definitions
U18 [0..28-1]
Object
=
U18 [0..28-1]
Variation
=
U18 [0..216-1]
Quantity
=
}
}
DNP V3.00 Data Object Library (Version 0.02)
12-9
The following illustrations serve as examples for more clarification:
PROD:
(blank)
B
B
A
0
16
0
3
2
1
2
2
21
2
5
30
1
In the above example:
• B, B, and A, represent the vendor name.
• PRN is private object #16 for vendor A B B.
• Count specifies that three definitions follow, with each definition consisting of
quantity, object, and variation.
12-10
DNP Users Group
The corresponding PRO object is:
(blank)
B
B
A
0
16
0
33
binary input
1
binary input
2
Counter 1
Counter 2
Analog 1
Analog 2
Analog 3
Analog 4
Analog 5
DNP V3.00 Data Object Library (Version 0.02)
12-11
12-12
DNP Users Group
13. APPLICATION OBJECT
DEFINITIONS
This section defines the application data objects using the rules established in section 2.
DECLARATION RULES FOR INFORMATION ELEMENTS.
13.1 APPLICATION IDENTIFIER
Data Object 90 - Variation: 01
Description:
The application identifier object is an information object used to represent an application
or operating system process within a device. This object is used in conjunction with the
application functions of the application layer to control software applications.
This object has no defined format and is simply used as a place holder. The free-format
qualifier of the application layer should be used to identify the application in question, or
if the application is unknown, the ALL qualifier should be used to specify all relevant
applications.
DNP V3.00 Data Object Library (Version 0.02)
13-1
13-2
DNP Users Group
14. ALTERNATE NUMERIC OBJECT
DEFINITIONS
This section defines the alternate or custom numeric representation data objects using the
rules established in section 2. DECLARATION RULES FOR INFORMATION
ELEMENTS.
14.1 SHORT FLOATING POINT
Data Object 100 - Variation: 01
Description:
The short floating point information object represents a calculated or measured scientific
value. The format of this object complies with the IEEE-754 standard for floating-point
number representation.
The value field holds the actual floating point number and follows the format for a short
real as specified by the IEEE-754 standard.
The flag field holds information about the point and has the same meaning as previous
objects.
The units field determines the units of the value field. This is the scientific or engineering
units associated with the measured or calculated quantity.
DNP V3.00 Data Object Library (Version 0.02)
14-1
Object Coding:
Units
Flag
7
0
7
0
Value
Sign
0
Exponent
0
FLAG
On-line
Restart
Communication lost
Remote forced data
Local forced data
Over-range
Reference check
Reserved
}
7
={
=
=
=
=
=
=
=
=
0
Significant
22
0
BS1 [0] <0, off-line; 1, on-line>
BS1 [1] <0, normal; 1, restart>
BS1 [2] <0, normal; 1, lost>
BS1 [3] <0, normal; 1, forced>
BS1 [4] <0>
BS1 [5] <0, normal; 1, over-range>
BS1 [6] <0, normal; 1, error>
BS1 [7] <0>
Narrative:
The absolute value can be derived from the value field as follows:
14-2
Absolute_Value
=
1.s0 s1 s2 s3 s4 .. s22 x 2 (Exp -127)
where:
si
=
Significant[i..i] and Exp= Exponent[0..7]
Sign:
Exponent:
Significant:
0 if number is positive, and 1 if the number is negative.
Power of 2 applied to 1. Significant.
Significant binary digits in value.
DNP Users Group
The units field has the following defined values:
0:
Volts p-p (peak-to-peak voltage)
1:
Amperes p-p (peak-to-peak current)
2:
Volts RMS
3:
Amperes RMS
4:
KW or kilowatts (real power or volt-amps resistive)
5:
KVA or kilo volt-amps (volt-amps total)
6:
KVAR or kilovars (imaginary power or volt-amps reactive)
7:
KwH (kilowatt hours)
8:
KVARH (kiloVAR hours)
9:
PF (power factor)
10:
Hz (frequency in cycles per second)
11:
w (frequency in radians)
12:
C (degrees Celsius)
13:
F (degrees Fahrenheit)
14:
K (degrees Kelvin)
15:
N (force in Newtons)
16:
kg (mass in kilograms)
17:
m/s2 (acceleration)
18:
N/m2 (pressure in Newtons per square meter)
19:
N*m (torque in Newton-meters)
DNP V3.00 Data Object Library (Version 0.02)
14-3
14.2 LONG FLOATING POINT
Data Object 100 - Variation: 02
Description:
The long floating point information object represents a calculated or measured scientific
value. The format of this object complies with the IEEE-754 standard for floating-point
number representation.
The value field holds the actual floating point number and follows the format for a long
real as specified by the IEEE-754 standard.
The flag field holds information about the point and has the same meaning as previous
objects.
The units field determines the units of the value field. This is the scientific or engineering
units associated with the measured or calculated quantity.
Object Coding:
Units
Flag
7
0
7
0
Value
Sign
0
0
FLAG
On-line
Restart
Communication lost
Remote forced data
Local forced data
Over-range
Reference check
Reserved
}
14-4
Exponent
10
0
={
=
=
=
=
=
=
=
=
Significant
51
0
BS1 [0] <0, off-line; 1, on-line>
BS1 [1] <0, normal; 1, restart>
BS1 [2] <0, normal; 1, lost>
BS1 [3] <0, normal; 1, forced>
BS1 [4] <0>
BS1 [5] <0, normal; 1, over-range>
BS1 [6] <0, normal; 1, error>
BS1 [7] <0>
DNP Users Group
Narrative:
The absolute value can be derived from the value field as follows:
Absolute_Value
=
1.s0 s1 s2 s3 s4 .. s51 x 2 (Exp -1023)
where:
si
=
Significant[i..i] and Exp= Exponent[0..7]
Sign:
Exponent:
Significant:
0 if number is positive, and 1 if the number is negative.
Power of 2 applied to 1. Significant.
Significant binary digits in value.
The units field has the following defined values:
0:
Volts p-p (peak-to-peak voltage)
1:
Amperes p-p (peak-to-peak current)
2:
Volts RMS
3:
Amperes RMS
4:
KW or kilowatts (real power or volt-amps resistive)
5:
KVA or kilo volt-amps (volt-amps total)
6:
KVAR or kilovars (imaginary power or volt-amps reactive)
7:
KwH (kilowatt hours)
8:
KVARH (kiloVAR hours)
9:
PF (power factor)
10:
Hz (frequency in cycles per second)
11:
w (frequency in radians)
12:
C (degrees Celsius)
13:
F (degrees Fahrenheit)
14:
K (degrees Kelvin)
15:
N (force in Newtons)
16:
kg (mass in kilograms)
17:
m/s2 (acceleration)
18:
N/m2 (pressure in Newtons per square meter)
19:
N*m (torque in Newton-meters)
DNP V3.00 Data Object Library (Version 0.02)
14-5
14.3 EXTENDED FLOATING POINT
Data Object 100 - Variation: 03
Description:
The extended floating point information object represents a calculated or measured
scientific value. The format of this object complies with the IEEE-754 standard for
floating-point number representation.
The value field holds the actual floating point number and follows the format for a temp
real as specified by the IEEE-754 standard.
The flag field holds information about the point and has the same meaning as previous
objects.
The units field determines the units of the value field. This is the scientific or engineering
units associated with the measured or calculated quantity.
Object Coding:
Units
Flag
7
0
7
0
Value
Sign
0
0
FLAG
On-line
Restart
Communication lost
Remote forced data
Local forced data
Over-range
Reference check
Reserved
}
14-6
Exponent
14
0
={
=
=
=
=
=
=
=
=
Significant
63
0
BS1 [0] <0, off-line; 1, on-line>
BS1 [1] <0, normal; 1, restart>
BS1 [2] <0, normal; 1, lost>
BS1 [3] <0, normal; 1, forced>
BS1 [4] <0>
BS1 [5] <0, normal; 1, over-range>
BS1 [6] <0, normal; 1, error>
BS1 [7] <0>
DNP Users Group
Narrative:
The absolute value can be derived from the value field as follows:
Absolute_Value
=
1.s0 s1 s2 s3 s4 .. s51 x 2 (Exp -1023)
where:
si
=
Significant[i..i] and Exp= Exponent[0..7]
Sign:
Exponent:
Significant:
0 if number is positive, and 1 if the number is negative.
Power of 2 applied to 1. Significant.
Significant binary digits in value.
The units field has the following defined values:
0:
Volts p-p (peak-to-peak voltage)
1:
Amperes p-p (peak-to-peak current)
2:
Volts RMS
3:
Amperes RMS
4:
KW or kilowatts (real power or volt-amps resistive)
5:
KVA or kilo volt-amps (volt-amps total)
6:
KVAR or kilovars (imaginary power or volt-amps reactive)
7:
KwH (kilowatt hours)
8:
KVARH (kiloVAR hours)
9:
PF (power factor)
10:
Hz (frequency in cycles per second)
11:
w (frequency in radians)
12:
C (degrees Celsius)
13:
F (degrees Fahrenheit)
14:
K (degrees Kelvin)
15:
N (force in Newtons)
16:
kg (mass in kilograms)
17:
m/s2 (acceleration)
18:
N/m2 (pressure in Newtons per square meter)
19:
N*m (torque in Newton-meters)
DNP V3.00 Data Object Library (Version 0.02)
14-7
14.4 SMALL-PACKED BINARY CODED DECIMAL
Data Object 101 - Variation: 01
Description:
The small-packed binary coded decimal information object represents a sequence of BCD
digits. Each BCD digit can represent a variety of information from control outputs to
analog inputs.
Object Coding:
Digit 4
3
SPBCD
14-8
Digit 3
0
= SQ4 {
Digit1
Digit2
Digit3
Digit4
}
3
=
=
=
=
Digit 2
0
3
Digit 1
0
3
0
UI4 [0..3] <0..10>
UI4 [0..3] <0..10>
UI4 [0..3] <0..10>
UI4 [0..3] <0..10>
DNP Users Group
14.5 MEDIUM-PACKED BINARY CODED DECIMAL
Data Object 101 - Variation: 02
Description:
The medium-packed binary coded decimal information object represents a sequence of
BCD digits. Each BCD digit can represent a variety of information from control outputs
to analog inputs.
Object Coding:
Digit 4
3
Digit 3
0
3
0
3
Digit 8
3
MPBCD =
Digit 2
0
3
0
3
Digit 7
SQ8 {
Digit1
Digit2
Digit3
Digit4
Digit5
Digit6
Digit7
Digit8
}
=
=
=
=
=
=
=
=
Digit 1
0
3
0
3
Digit 6
0
Digit 5
0
UI4 [0..3] <0..10>
UI4 [0..3] <0..10>
UI4 [0..3] <0..10>
UI4 [0..3] <0..10>
UI4 [0..3] <0..10>
UI4 [0..3] <0..10>
UI4 [0..3] <0..10>
UI4 [0..3] <0..10>
DNP V3.00 Data Object Library (Version 0.02)
14-9
14.6 LARGE-PACKED BINARY CODED DECIMAL
Data Object 101 - Variation: 03
Description:
The large-packed binary coded decimal information object represents a sequence of BCD
digits. Each BCD digit can represent a variety of information from control outputs to
analog inputs.
Object Coding:
Digit 4
3
Digit 3
0
3
0
3
0
3
0
3
Digit 8
3
LPBCD
14-10
=
0
3
0
3
0
3
3
0
3
0
3
0
3
0
Digit 5
Digit 10
Digit 15
SQ16 {
Digit1=
Digit2=
Digit3=
Digit4=
Digit5=
Digit6=
Digit7=
Digit8=
Digit9=
Digit10=
Digit11=
Digit12=
Digit13=
Digit14=
Digit15=
}
Digit 1
0
Digit 6
Digit 11
Digit 16
3
3
Digit 7
Digit 12
3
Digit 2
0
0
Digit 9
Digit 14
0
Digit 13
0
UI4 [0..3] <0..10>
UI4 [0..3] <0..10>
UI4 [0..3] <0..10>
UI4 [0..3] <0..10>
UI4 [0..3] <0..10>
UI4 [0..3] <0..10>
UI4 [0..3] <0..10>
UI4 [0..3] <0..10>
UI4 [0..3] <0..10>
UI4 [0..3] <0..10>
UI4 [0..3] <0..10>
UI4 [0..3] <0..10>
UI4 [0..3] <0..10>
UI4 [0..3] <0..10>
UI4 [0..3] <0..10>
DNP Users Group
LIST OF ABBREVIATIONS AND
ACRONYMS
ASCII
American Standard Code for Information Interchange
BCD
BIN
BS
binary coded decimal
CRC
CTO
CTO
CWD
cyclic redundancy check
common time object
common time of occurrence
change working directory
DA
DAC
DNP
distributed automation
data acquisition and control
Distributed Network Protocol
EBCDIC
EXEC
extended binary coded decimal
execute
F
FIFO
fixed point
first-in-first-out
I
ID
IEC
IEEE
integer
identification
International Electrotechnical Commission
Institute of Electrical and Electronics Engineers
LEN
LPBCD
length
large-packed binary coded decimal
MPBCD
MSEC
medium-packed binary coded decimal
millisecond
OS
octet string
bit string
DNP V3.00 Data Object Library (Version 0.02)
1
PCB
PRN
PRO
PROD
PWD
pattern control block
private registration number
private registration object
private registration object description
(return to) present working directory
R
RESP
RMS
real
response
root mean squared
SCADA
SPBCD
supervisory control and data acquisition
small-packed binary coded decimal
UF
UI
unsigned fixed point
unsigned integer
2
DNP Users Group
DNP V3.00
SUBSET DEFINITIONS
Document Number: P009-0IG.SUB
Version: 2.00
Date: November, 1995
NOTICE OF RIGHTS - DNP USERS GROUP
The contents of this manual are the property of the DNP Users Group. Revisions or
additions to the definition and functionality of the DNP Protocol cannot be made
without express written agreement from the DNP Users Group or its duly authorized
party. In addition, no part of this document may be altered or revised or added to in
any form or by any means, except as permitted by written agreement with the DNP
Users Group or a Party duly authorized by the DNP Users Group.
The DNP Users Group has made every reasonable attempt to ensure the
completeness and accuracy of this document. However, the information contained in
this manual is subject to change without notice, and does not represent a
commitment on the part of the DNP Users Group. An update program for DNP
documents is provided upon request by the DNP Users Group.
TRADEMARK NOTICES
DNP is a trademark of the DNP Users Group. Any brand and product names
mentioned in this document are trademarks or registered trademarks of their
respective companies.
MODIFICATION RECORD
ii
VERSION
DATE
INITIALS
COMMENT
0.01
94.09.20
GG/PM
0.02
95.06.08
GG
Changes from Jan 1995 DNP Users Group
meeting and May 30 review.
1.00
95.07.12
GG
Changes due to comments from the DNP
Users Group Technical Committee.
2.00
95.11.29
ST
Changes to delete Harris references.
Changes from Aug 19 review.
DNP Users Group
P009-0IG.SUB, Version 2.00
TABLE OF CONTENTS
ABOUT THIS GUIDE ...........................................................................vi
PURPOSE OF THIS GUIDE .............................................................vi
WHO SHOULD USE THIS GUIDE.................................................vi
ADDITIONAL DOCUMENTATION...............................................vi
HOW THIS GUIDE IS ORGANIZED ............................................ vii
CONVENTIONS USED IN THIS GUIDE .................................... viii
OVERVIEW ........................................................................................... ix
TERMINOLOGY ............................................................................... ix
READING THE SUBSET TABLES ....................................................x
GOALS AND ASSUMPTIONS........................................................ xii
Chapter 1: LEVEL 1 DNP V3.00 IMPLEMENTATION (DNP - L1)..... 1
1.1 INTENDED USE ........................................................................ 1
1.2 GENERAL DESCRIPTION ....................................................... 1
1.3 IMPLEMENTATION TABLE .................................................... 2
Chapter 2: LEVEL 2 DNP V3.00 IMPLEMENTATION (DNP-L2)....... 1
2.1 INTENDED USE ........................................................................ 1
2.2 GENERAL DESCRIPTION ....................................................... 1
2.3 IMPLEMENTATION TABLE .................................................... 1
Chapter 3: LEVEL 3 DNP V3.00 IMPLEMENTATION (DNP - L3)..... 1
3.1 INTENDED USE ........................................................................ 1
3.2 GENERAL DESCRIPTION ....................................................... 1
3.3 IMPLEMENTATION TABLE .................................................... 2
Chapter 4: IMPLEMENTATION RULES AND RECOMMENDATIONS
.................................................................................................................. 1
4.1 ERROR RESPONSES................................................................. 1
4.1.1 Rules ..................................................................................... 1
4.2 DATA CLASSES AND EVENTS ............................................... 2
4.2.1 Rules ..................................................................................... 2
4.2.2 Recommendations................................................................ 4
4.3 SLAVE DEVICE START-UP...................................................... 5
4.3.1 Rules ..................................................................................... 5
4.3.2 Recommendations................................................................ 6
4.4 UNSOLICITED RESPONSES ................................................... 6
4.4.1 Rules ..................................................................................... 6
4.5 OPERATING BINARY OUTPUTS........................................... 7
4.5.1 Rules ..................................................................................... 7
4.5.2 Recommendations................................................................ 7
DNP V3.00 Subset Definitions
P009-0IG.SUB, Version 2.00
iii
4.6 FRAGMENTS AND FRAMES ................................................... 8
4.6.1 Rules ..................................................................................... 8
4.6.2 Recommendations ................................................................ 8
4.7 MULTIPLE OBJECTS IN A SINGLE REQUEST..................... 9
4.7.1 Rules ..................................................................................... 9
4.8 MULTIPLE OBJECTS IN A SINGLE RESPONSE ................... 9
4.8.1 Rules ..................................................................................... 9
4.9 CONFIRMATION AND RETRIES ........................................... 9
4.9.1 Rules ..................................................................................... 9
4.9.2 Recommendations .............................................................. 10
4.10 WITH-FLAG AND WITHOUT-FLAG VARIATIONS......... 11
4.10.1 Rules ................................................................................. 11
4.11 16-BIT AND 32-BIT VARIATIONS ....................................... 12
4.11.1 Rules ................................................................................. 12
4.11.2 Rules for Analog Inputs and the OVER-RANGE Flag .... 12
4.11.3 Rules for Counter Objects and the ROLL-OVER Flag.... 14
4.11.4 Recommendations Regarding the ROLL-OVER Flag...... 14
4.12 TIME TAGGED BINARY INPUT EVENTS ......................... 15
4.12.1 Rules ................................................................................. 15
4.12.2 Recommendations ............................................................ 15
4.13 FREEZE OPERATIONS ......................................................... 15
4.13.1 Rules ................................................................................. 16
4.14.1 Rules ................................................................................. 16
Chapter 5: CONFORMANCE................................................................ 1
5.1 SLAVE DEVICES........................................................................ 1
5.2 MASTER DEVICES.................................................................... 2
Appendix A: DEVICE PROFILE DOCUMENT FORMAT.................. 1
GLOSSARY OF TERMS ......................................................................... 8
LIST OF ACRONYMS AND ABBREVIATIONS ............................... 10
iv
DNP Users Group
P009-0IG.SUB, Version 2.00
LIST OF TABLES
Table 1 Qualifiers Used in the Subset Definitions ............................ xiii
Table 1.3-1 Level 1 Implementation (DNP-L1) ...................................3
Table 2.3-1 Level 2 Implementation (DNP-L2) ...................................2
Table 3.3-1 Level 3 Implementation (DNP-L3) ...................................2
Table 4.1-1 Valid Error Responses ......................................................2
Table 4.11-1 Examples of Over-Range Conditions and Values........... 13
DNP V3.00 Subset Definitions
P009-0IG.SUB, Version 2.00
v
ABOUT THIS GUIDE
PURPOSE OF THIS GUIDE
This document defines the implementation subsets, or levels, defined for
the Distributed Network Protocol (DNP) V3.00 Application Layer. It is
intended to be used as a reference for determining compatibility between
implementations of the DNP V3.00 Application Layer. It also briefly
discusses some compatibility issues with respect to the DNP V3.00 Data
Link Layer and Transport Function.
This document describes several subsets of the protocol, for the purpose of
giving vendors and customers a common set of terms for describing what
they have implemented and what they require, respectively.
WHO SHOULD USE THIS GUIDE
This guide is intended to be used by the following people, although its
audience is not necessarily limited to those listed here:
• Designers responsible for determining what portion of the protocol to
implement.
• Systems engineers responsible for determining compatibility between
components of a network.
• Purchasing agents or certification agencies responsible for determining
whether a vendor's product meets customers' standards.
ADDITIONAL DOCUMENTATION
If you require more detail than this document provides, several supporting
texts are available. These include:
• Distributed Network Protocol 3.0 Basic 4-Document Set including:
-
vi
DNP V3.00 Data Link Layer (P009-0PD.DL) Version 0.02
DNP V3.00 Transport Functions (P009-0PD.TF) Version 0.01
DNP Users Group
P009-0IG.SUB, Version 2.00
-
DNP V3.00 Application Layer (P009-0PD.APP) Version 0.03
DNP V3.00 Data Object Library (P000-0BL) Version 0.02
HOW THIS GUIDE IS ORGANIZED
The organization of this guide is described below. Each chapter of the guide
describes one subset of the DNP V3.00 Application Layer protocol.
OVERVIEW describes basic concepts concerning DNP subsets: basic
terminology, how to interpret the implementation tables,
and the duties of devices implementing the subsets. It briefly
discusses the goals used to develop the subsets.
Chapter 1:
LEVEL 1 DNP V3.00 IMPLEMENTATION (DNP-L1)
describes the minimum subset of the protocol that can be
implemented, typically between a master station and an
Intelligent Electronic Device (IED).
Chapter 2:
LEVEL 2 DNP V3.00 IMPLEMENTATION (DNP-L2)
describes a subset of the protocol, slightly larger than Level
1. It is typically implemented between a master station and a
large IED or small Remote Terminal Unit (RTU).
Chapter 3:
LEVEL 3 DNP V3.00 IMPLEMENTATION (DNP-L3)
describes a subset of the protocol, larger than Level 2, that
can be implemented between a master station and a more
advanced RTU.
Chapter 4:
IMPLEMENTATION RULES AND
RECOMMENDATIONS describes rules and
recommendations applying to all levels of DNP V3.00
implementation.
Chapter 5:
CONFORMANCE describes the conditions under which a
device is said to conform to a given DNP subset.
Appendix A: DEVICE PROFILE DOCUMENT FORMAT describes the
information a device vendor must include in a document
describing a device's implementation of DNP V3.00
DNP V3.00 Subset Definitions
P009-0IG.SUB, Version 2.00
vii
CONVENTIONS USED IN THIS GUIDE
There are a few formatting conventions used in this guide to make it easier
to read and understand. They are listed below.
• New or special terms are highlighted in bold text.
• Chapter references are highlighted in bold text, with the chapter title in
CAPITAL LETTERS (for example, Chapter 2: SPECIAL
REQUIREMENTS). Table names are also bold (e.g. AXXX_CFG).
• References to main section titles are highlighted using italics, as are
book and document titles, and words used with special emphasis.
• Lists of procedural instructions are numbered in the order they are to
be performed. Other lists of information are bulleted, like this list.
• Specific function and field names are in CAPITAL LETTERS, but not
bold (e.g. TRIP function, GROUP ADDRESS field).
viii
DNP Users Group
P009-0IG.SUB, Version 2.00
OVERVIEW
This section describes various concepts concerning DNP V3.00 protocol
subsets in general.
TERMINOLOGY
This section defines some of the terms used throughout this document.
When a Master or Slave satisfies all the requirements of a particular DNP
V3.00 subset, it is said to implement a particular level of the protocol. The
term "Level" is chosen so as to not conflict with DNP data classes or the
Open Systems Interconnect (OSI) concept of layers. The abbreviation for a
DNP subset implementation consists of "DNP", a dash, and "L" followed by
the level number.
For example, a vendor may be able to say, "This device implements the
DNP V3.00 Application Layer protocol Level 1", or just "This device
implements DNP - L1".
!
NOTE:
This document specifies only the minimum
requirements for a particular implementation level. A
device may implement extra features in addition to these
requirements and still conform. Refer to CHAPTER 5:
CONFORMANCE for more details.
The following terms are used throughout this document:
configure
To initialize a device so it operates in a particular way. For
instance, a customer may configure a device so the device
never requests data link confirmations. A vendor or
customer may configure a device using a variety of
mechanisms (e.g. parameters in NVRAM, parameters in
ROM, dip switches or hardware jumpers).
Master A device that initiates requests to gather data or perform controls
using DNP.
DNP V3.00 Subset Definitions
P009-0IG.SUB, Version 2.00
ix
Slave
A device that gathers data or performs control operations in
response to DNP requests from the Master, and sends
response messages in return. A Slave device may also
generate DNP Unsolicited Responses.
parse
To resolve a request or response into component parts. In
the context of DNP V3.00 messages, to parse a message
means a device can break the message into pieces, each of
which consists of a header and sometimes some
corresponding data. If a device is able to parse a message, it
can recognize each piece of a message. It does not necessarily
make use of the data found in that message. However, it
must make any confirmation responses or other responses
that the message requires.
report
To actually send to a Master device a particular object
variation. Used only in connection with Slave devices. A
Slave device may parse requests for a larger subset of objects
than it actually reports.
support
To be able to send or parse a particular set of DNP objects,
variations, function codes and/or qualifiers.
READING THE SUBSET TABLES
The subsets of the DNP V3.00 protocol discussed in this document are
described in a common format. Each chapter of this document describing
an implementation level contains a table having the following fields:
OBJECT
These fields describe a DNP application layer object:
Obj
Var
Description
x
The object group
The object variation
The text name of the object
DNP Users Group
P009-0IG.SUB, Version 2.00
REQUEST
These fields describe the set of DNP V3.00 objects, function
codes, and qualifiers a Slave device must be able to parse as a
part of an incoming request in order to have implemented
the subset.
Func Codes
A list of the request function codes that the
Slave must accept as operators on this object.
Qual Codes
A list of the qualifier codes the Slave must
parse in association with this object.
If these fields are blank, it means the Slave need not be able
to parse the specified object in order to implement the
subset.
RESPONSE
These fields describe the set of DNP V3.00 objects, function
codes, and qualifiers a Master device must be able to parse
from an incoming response or unsolicited response in order
to have implemented the subset. These fields also define the
minimum subset of responses a Slave device may make.
Func Codes
A list of the response function codes the
Master must accept as operators on this
object.
Qual Codes
A list of the qualifier codes the Master must
parse in association with this object.
If these fields are blank, it means the Master need not be
able to parse the specified object in order to implement the
subset.
There are three levels of implementation of DNP V3.00 defined within this
document. Each level builds upon the level preceding it. The additions to a
level from the preceding level are highlighted by shading in the table.
!
NOTE:
The subset describes the minimum set of objects,
function codes, and qualifiers the devices must parse in
order to implement the subset. If an object is supported, it
must be used with the function and qualifier codes in order
to implement the subset. It does not specify that a Slave
device must actually report inputs, outputs and data for all
of the objects in the subset.
DNP V3.00 Subset Definitions
P009-0IG.SUB, Version 2.00
xi
For example, suppose a subset table contains the following line:
OBJECT
REQUEST
RESPONSE
(slave must parse)
(master must
parse)
Obj
Va
r
Description
Func
Codes
Qual
Codes
(hex)
Func
Codes
Qual
Codes
(hex)
30
4
16-Bit Analog Input without Flag
1
00, 01, 06
129,
130
01
......
This entry indicates the following:
•
A Slave device must accept and respond to any READ request
(Function Code 1) of 16-Bit Analog Input Without Flag objects.
The READ request may use either 8-bit start and stop indices
(Qualifier Code 0x00), 16-bit start and stop indices (Qualifier
Code 0x01), or no range field (Qualifier Code 0x06). The Slave
device need not parse READ requests for 16-Bit Analog Input
Without Flag objects using any other Qualifier Codes. The Master
device cannot include a 16-Bit Analog Input Without Flag object
in any request containing a function code other than READ.
•
The Slave need not actually report any analog inputs. It may set an
Internal Indication bit in its response, or return a null response, as
discussed in section 4.1 Error Responses.
•
A Master device must be able to parse either RESPONSEs
(Function Code 129) or UNSOLICITED RESPONSEs (Function
Code 130) from the Slave containing 16-Bit Analog Input Without
Flag objects. The response must use Qualifier Code 0x01. The
Master device need not parse responses or unsolicited responses
containing 16-Bit Analog Input Without Flag objects using any
other Qualifier Codes.
•
The Master need not use the data supplied by the Slave for any
purpose, but can discard it after sending any necessary
confirmation.
GOALS AND ASSUMPTIONS
These subset definitions were prepared with the following goals:
xii
DNP Users Group
P009-0IG.SUB, Version 2.00
•
•
•
•
Minimize the complexity of implementation. Where complexity must
be added, it was added at the Master rather than the Slave.
Minimize the bandwidth used.
Allow all data provided by a Slave to be retrieved at any Level.
Allow flexibility for a variety of different, but interoperable
implementations.
It was assumed that the simpler the Slave device, the fewer points it would
provide. Therefore, there would be less need for the more complex point
range specifications available in DNP.
As a result of these goals and assumptions, the lower level subset
definitions are based around polls of Class Data Objects. In a typical
minimum implementation, it is expected that a Master device will poll
frequently for Class 1, 2 or 3 Data, interspersed with infrequent Class 0
Data polls. More advanced implementations may take advantage of
Unsolicited Responses and the more complex polling features available in
DNP. See 4.2 Data Classes and Events for more discussion regarding the
use of data classes.
Qualifiers are a complex part of DNP, so the number of qualifiers required
to be supported by either a Master or a Slave devices was limited. Table 1
illustrates the subset of qualifiers chosen and the intended use of each
qualifier. There may be a few exceptions to these rules.
Qualifier
(hex)
Use in a Request
Use in a Response
00, 01
A range of static points, or a
single point with a point number
Static objects
06
All points
Not valid
07, 08
A limited quantity of events
A single point with no number
(e.g. Time and Date)
A single point with no number
(e.g. Time and Date)
17, 28
Controls (usually one or more
unrelated points)
Event objects (usually one or
more unrelated points)
Table 1 Qualifiers Used in the Subset Definitions
DNP V3.00 Subset Definitions
P009-0IG.SUB, Version 2.00
xiii
Chapter 1: LEVEL 1 DNP V3.00
IMPLEMENTATION (DNP - L1)
This chapter describes the minimum subset of the DNP V3.00
Application Layer that can be supported and still be said to implement
the protocol. This implementation level is called Level 1 (L1).
1.1 INTENDED USE
This level of implementation is intended to represent the simplest
implementation of DNP V3.00 for communicating between a Master
and a typical Intelligent Electronic Device (IED). It would typically be
used between a master station or data concentrator and a small end
device (eg. meter, relay, auto-recloser or capacitor bank controller). It
is intended for use with Slave devices whose input and output points
are local to the device.
1.2 GENERAL DESCRIPTION
The Level 1 subset is based around Class Data polling, as described in
the Goals and Assumptions section of the OVERVIEW. A Level 1
Slave must accept requests for:
•
•
READs of Class Data Objects
READs of Binary Output and Analog Output objects, if such
outputs exist on the Slave.
!
NOTE:
If such objects do not exist, the Slave is
allowed to respond OBJECT UNKNOWN (see 4.1
Error Responses).
DNP V3.00 Subset Definitions
P009-0IG.SUB, Version 2.00
1
•
•
•
•
Control operations to Binary Output or Analog Outputs, if they exist
on the Slave. If such objects do not exist, the Slave is allowed to
respond OBJECT UNKNOWN.
WRITEs to the RESTART Internal Indication
COLD RESTARTs
DELAY MEASUREMENTs and WRITEs to Time and Date, if the
Slave sets the TIME SYNCHRONIZATION REQUIRED Internal
Indication (See 4.13 Time Synchronization)
A Level 1 Master must accept a subset of object variations that is about
one-third of the total number defined in DNP, but includes most basic data
types:
•
•
•
•
Binary Inputs and Events
Counters and Counter Events
Analog Inputs and Events
Binary and Analog Output Status
The following are specifically NOT included:
•
•
Frozen objects
Time-stamped objects, with the exception of Binary Inputs, because
Sequence of Events (SOE) information is a common industry
requirement
!
NOTE:
Although a Level 1 Master must be able to
parse many objects, a Level 1 Slave is not required to
generate them. For example, a Slave need not provide
Binary Output Status or Analog Output Status objects if it
does not control any of these outputs. The Slave may also
choose to report Binary Input Without Time objects instead
of Binary Input Change With Relative Time objects.
A Level 1 Slave may send Unsolicited Responses of some objects, but this
capability must be configurable. See 4.4 Unsolicited Responses.
1.3 IMPLEMENTATION TABLE
Table 1.3-1 describes the objects, function codes, and qualifiers used in a
Level 1 DNP V3.00 implementation.
2
DNP Users Group
P009-0IG.SUB, Version 2.00
Table 1.3-1 Level 1 Implementation (DNP-L1)
OBJECT
Obj
Var
Description
REQUEST
RESPONSE
(slave must parse)
(master must parse)
Func
Codes
(dec)
Qual
Codes
(hex)
Func
Codes
(dec)
Qual
Codes
(hex)
1
0
Binary Input - All Variations
1
1
Binary Input
129
00, 01
1
2
Binary Input with Status
129
00, 01
2
0
Binary Input Change - All Variations
2
1
Binary Input Change without Time
129, 130
17, 28
2
2
Binary Input Change with Time
129, 130
17, 28
2
3
Binary Input Change with Relative Time
129, 130
17, 28
10
0
Binary Output - All Variations
10
1
Binary Output
10
2
Binary Output Status
129
00, 01
12
0
Control Block - All Variations
12
1
Control Relay Output Block
129
echo of
request
12
2
Pattern Control Block
12
3
Pattern Mask
20
0
Binary Counter - All Variations
20
1
32-Bit Binary Counter
129
00, 01
20
2
16-Bit Binary Counter
129
00, 01
20
3
32-Bit Delta Counter
129
00, 01
20
4
16-Bit Delta Counter
129
00, 01
20
5
32-Bit Binary Counter without Flag
129
00, 01
20
6
16-Bit Binary Counter without Flag
129
00, 01
20
7
32-Bit Delta Counter without Flag
129
00 ,01
20
8
16-Bit Delta Counter without Flag
129
00, 01
21
0
1
3, 4, 5,
6
06
17, 28
Frozen Counter - All Variations
21
1
32-Bit Frozen Counter
21
2
16-Bit Frozen Counter
21
3
32-Bit Frozen Delta Counter
21
4
16-Bit Frozen Delta Counter
21
5
32-Bit Frozen Counter with Time of Freeze
21
6
16-Bit Frozen Counter with Time of Freeze
21
7
32-Bit Frozen Delta Counter with Time of Freeze
DNP V3.00 Subset Definitions
P009-0IG.SUB, Version 2.00
3
OBJECT
4
Description
REQUEST
RESPONSE
(slave must parse)
(master must parse)
Obj
Var
Func
Codes
(dec)
21
8
16-Bit Frozen Delta Counter with Time of Freeze
21
9
32-Bit Frozen Counter without Flag
21
10
16-Bit Frozen Counter without Flag
21
11
32-Bit Frozen Delta Counter without Flag
21
12
16-Bit Frozen Delta Counter without Flag
22
0
Counter Change Event - All Variations
22
1
32-Bit Counter Change Event without Time
129, 130
17, 28
22
2
16-Bit Counter Change Event without Time
129, 130
17, 28
22
3
32-Bit Delta Counter Change Event without Time
129, 130
17, 28
22
4
16-Bit Delta Counter Change Event without Time
129, 130
17, 28
22
5
32-Bit Counter Change Event with Time
22
6
16-Bit Counter Change Event with Time
22
7
32-Bit Delta Counter Change Event with Time
22
8
16-Bit Delta Counter Change Event with Time
23
0
Frozen Counter Event - All Variations
23
1
32-Bit Frozen Counter Event without Time
23
2
16-Bit Frozen Counter Event without Time
23
3
32-Bit Frozen Delta Counter Event without Time
23
4
16-Bit Frozen Delta Counter Event without Time
23
5
32-Bit Frozen Counter Event with Time
23
6
16-Bit Frozen Counter Event with Time
23
7
32-Bit Frozen Delta Counter Event with Time
23
8
16-Bit Frozen Delta Counter Event with Time
30
0
Analog Input - All Variations
30
1
32-Bit Analog Input
129
00, 01
30
2
16-Bit Analog Input
129
00, 01
30
3
32-Bit Analog Input without Flag
129
00, 01
30
4
16-Bit Analog Input without Flag
129
00, 01
31
0
Frozen Analog Input - All Variations
31
1
32-Bit Frozen Analog Input
31
2
16-Bit Frozen Analog Input
31
3
32-Bit Frozen Analog Input with Time of Freeze
31
4
16-Bit Frozen Analog Input with Time of Freeze
Qual
Codes
(hex)
Func
Codes
(dec)
DNP Users Group
P009-0IG.SUB, Version 2.00
Qual
Codes
(hex)
OBJECT
Description
REQUEST
RESPONSE
(slave must parse)
(master must parse)
Obj
Var
31
5
32-Bit Frozen Analog Input without Flag
31
6
16-Bit Frozen Analog Input without Flag
32
0
Analog Change Event - All Variations
32
1
32-Bit Analog Change Event without Time
129, 130
17,28
32
2
16-Bit Analog Change Event without Time
129, 130
17,28
32
3
32-Bit Analog Change Event with Time
32
4
16-Bit Analog Change Event with Time
33
0
Frozen Analog Event - All Variations
33
1
32-Bit Frozen Analog Event without Time
33
2
16-Bit Frozen Analog Event without Time
33
3
32-Bit Frozen Analog Event with Time
33
4
16-Bit Frozen Analog Event with Time
40
0
Analog Output Status - All Variations
40
1
32-Bit Analog Output Status
40
2
16-Bit Analog Output Status
129
00, 01
41
0
Analog Output Block - All Variations
41
1
32-Bit Analog Output Block
41
2
16-Bit Analog Output Block
129
echo of
request
50
0
Time and Date - All Variations
50
1
Time and Date
129, 130
07,
50
2
Time and Date with Interval
51
0
Time and Date CTO - All Variations
51
1
Time and Date CTO
Func
Codes
(dec)
1
Qual
Codes
(hex)
Func
Codes
(dec)
Qual
Codes
(hex)
06
3, 4, 5,
6
17, 28
2 (see
4.14)
07,
quantity=1
quantity=1
51
2
Unsynchronized Time and Date CTO
129, 130
07,
quantity=1
52
0
Time Delay - All Variations
52
1
Time Delay Coarse
129
07,
quantity=1
52
2
Time Delay Fine
129
07,
quantity=1
60
0
60
1
Class 0 Data
1
06
60
2
Class 1 Data
1
06,07,08
DNP V3.00 Subset Definitions
P009-0IG.SUB, Version 2.00
5
REQUEST
RESPONSE
(slave must parse)
(master must parse)
OBJECT
Obj
Var
Description
Func
Codes
(dec)
60
3
Class 2 Data
1
06,07,08
60
4
Class 3 Data
1
06,07,08
70
1
File Identifier
80
1
Internal Indications
2
00,
Qual
Codes
(hex)
Func
Codes
(dec)
index=7
6
81
1
Storage Object
82
1
Device Profile
83
1
Private Registration Object
83
2
Private Registration Object Descriptor
90
1
Application Identifier
100
1
Short Floating Point
100
2
Long Floating Point
100
3
Extended Floating Point
101
1
Small Packed Binary-Coded Decimal
101
2
Medium Packed Binary-Coded Decimal
101
3
Large Packed Binary-Coded Decimal
No object
13
No object
23
(see
4.14)
DNP Users Group
P009-0IG.SUB, Version 2.00
Qual
Codes
(hex)
Chapter 2: LEVEL 2 DNP V3.00
IMPLEMENTATION (DNP-L2)
This chapter describes the second smallest subset of the DNP V3.00
Application Layer. This implementation level is called Level 2 (L2).
2.1 INTENDED USE
This level contains a few more features than the Level 1
implementation. It is intended for communications between a master
station or data concentrator and a device that could be called either a
large Intelligent Electronic Device (IED) or a small Remote Terminal
Unit (RTU). Typically, the input and output points of such a device
would be local to the device.
2.2 GENERAL DESCRIPTION
A Level 2 Slave implementation is the same as a Level 1 Slave
implementation with the following additions:
•
•
•
•
•
A Level 2 Slave accepts FREEZE requests on Binary Counter objects
(not Analog Input objects or Frozen Counters). See 4.13 Freeze
Operations.
A Level 2 Slave parses READ requests for variation 0 of specific
objects.
A Level 2 Slave parses READ requests for variations 1, 2 and 3 of
Binary Input Change objects.
A Level 2 Slave parses READ requests for Frozen Counter objects and
may report Frozen Counter objects (but not Frozen Delta Counters)
A Level 2 Slave may send unsolicited responses containing static data,
within the constraints described in CHAPTER 4:
IMPLEMENTATION RULES AND RECOMMENDATIONS.
2.3 IMPLEMENTATION TABLE
DNP V3.00 Subset Definitions
P009-0IG.SUB, Version 2.00
1
Table 2.3-1 Describes the objects, function codes, and qualifiers used in a
Level 2 DNP V3.00 implementation. Note that additions and
modifications from implementation Level 1 are shaded.
Table 2.3-1 Level 2 Implementation (DNP-L2)
OBJECT
RESPONSE
(master must parse)
Obj
Var
1
0
Binary Input - All Variations
1
1
Binary Input
129, 130
00, 01
1
2
Binary Input with Status
129, 130
00, 01
2
0
Binary Input Change - All Variations
1
06,07,08
2
1
Binary Input Change without Time
1
06,07,08
129, 130
17, 28
2
2
Binary Input Change with Time
1
06,07,08
129, 130
17, 28
2
3
Binary Input Change with Relative Time
1
06,07,08
129, 130
17, 28
10
0
Binary Output - All Variations
1
06
10
1
Binary Output
10
2
Binary Output Status
129, 130
00, 01
12
0
Control Block - All Variations
12
1
Control Relay Output Block
129
echo of
request
12
2
Pattern Control Block
12
3
Pattern Mask
20
0
Binary Counter - All Variations
20
1
32-Bit Binary Counter
129, 130
00, 01
20
2
16-Bit Binary Counter
129, 130
00, 01
20
3
32-Bit Delta Counter
129, 130
00, 01
20
4
16-Bit Binary Counter
129, 130
00, 01
20
5
32-Bit Binary Counter without Flag
129, 130
00, 01
20
6
16-Bit Binary Counter without Flag
129, 130
00, 01
20
7
32-Bit Delta Counter without Flag
129, 130
00 ,01
20
8
16-Bit Delta Counter without Flag
129, 130
00 ,01
21
0
Frozen Counter - All Variations
21
1
32-Bit Frozen Counter
129, 130
00, 01
21
2
16-Bit Frozen Counter
129, 130
00, 01
2
Description
REQUEST
(slave must parse)
Func
Codes
(dec)
1
Qual
Codes
(hex)
Qual
Codes
(hex)
06
3, 4, 5,
6
17, 28
1, 7, 8,
9, 10
06
1
Func
Codes
06
DNP Users Group
P009-0IG.SUB, Version 2.00
OBJECT
Description
REQUEST
RESPONSE
(slave must parse)
(master must parse)
Obj
Var
21
3
32-Bit Frozen Delta Counter
21
4
16-Bit Frozen Delta Counter
21
5
32-Bit Frozen Counter with Time of Freeze
21
6
16-Bit Frozen Counter with Time of Freeze
21
7
32-Bit Frozen Delta Counter with Time of Freeze
21
8
16-Bit Frozen Delta Counter with Time of Freeze
21
9
32-Bit Frozen Counter without Flag
129, 130
00, 01
21
10
16-Bit Frozen Counter without Flag
129, 130
00, 01
21
11
32-Bit Frozen Delta Counter without Flag
21
12
16-Bit Frozen Delta Counter without Flag
22
0
Counter Change Event - All Variations
22
1
32-Bit Counter Change Event without Time
129, 130
17, 28
22
2
16-Bit Counter Change Event without Time
129, 130
17, 28
22
3
32-Bit Delta Counter Change Event without Time
22
4
16-Bit Delta Counter Change Event without Time
22
5
32-Bit Counter Change Event with Time
22
6
16-Bit Counter Change Event with Time
22
7
32-Bit Delta Counter Change Event with Time
22
8
16-Bit Delta Counter Change Event with Time
23
0
Frozen Counter Event - All Variations
23
1
32-Bit Frozen Counter Event without Time
23
2
16-Bit Frozen Counter Event without Time
23
3
32-Bit Frozen Delta Counter Event without Time
23
4
16-Bit Frozen Delta Counter Event without Time
23
5
32-Bit Frozen Counter Event with Time
23
6
16-Bit Frozen Counter Event with Time
23
7
32-Bit Frozen Delta Counter Event with Time
23
8
16-Bit Frozen Delta Counter Event with Time
30
0
Analog Input - All Variations
30
1
32-Bit Analog Input
129, 130
00, 01
30
2
16-Bit Analog Input
129, 130
00, 01
30
3
32-Bit Analog Input without Flag
129, 130
00, 01
30
4
16-Bit Analog Input without Flag
129, 130
00, 01
DNP V3.00 Subset Definitions
P009-0IG.SUB, Version 2.00
Func
Codes
(dec)
1
1
Qual
Codes
(hex)
Func
Codes
Qual
Codes
(hex)
06,07,08
06
3
OBJECT
Description
REQUEST
RESPONSE
(slave must parse)
(master must parse)
Obj
Var
31
0
Frozen Analog Input - All Variations
31
1
32-Bit Frozen Analog Input
31
2
16-Bit Frozen Analog Input
31
3
32-Bit Frozen Analog Input with Time of Freeze
31
4
16-Bit Frozen Analog Input with Time of Freeze
31
5
32-Bit Frozen Analog Input without Flag
31
6
16-Bit Frozen Analog Input without Flag
32
0
Analog Change Event - All Variations
32
1
32-Bit Analog Change Event without Time
129, 130
17,28
32
2
16-Bit Analog Change Event without Time
129, 130
17,28
32
3
32-Bit Analog Change Event with Time
32
4
16-Bit Analog Change Event with Time
33
0
Frozen Analog Event - All Variations
33
1
32-Bit Frozen Analog Event without Time
33
2
16-Bit Frozen Analog Event without Time
33
3
32-Bit Frozen Analog Event with Time
33
4
16-Bit Frozen Analog Event with Time
40
0
Analog Output Status - All Variations
40
1
32-Bit Analog Output Status
40
2
16-Bit Analog Output Status
129, 130
00, 01
41
0
Analog Output Block - All Variations
41
1
32-Bit Analog Output Block
41
2
16-Bit Analog Output Block
129
echo of
request
50
0
Time and Date - All Variations
50
1
Time and Date
129, 130
07,
50
2
Time and Date with Interval
51
0
Time and Date CTO - All Variations
51
1
Time and Date CTO
Func
Codes
(dec)
1
1
Qual
Codes
(hex)
Func
Codes
Qual
Codes
(hex)
06,07,08
06
3, 4, 5,
6
17, 28
2 (see
4.14)
07,
quantity=1
quantity=1
51
2
Unsynchronized Time and Date CTO
129, 130
07,
quantity=1
52
0
Time Delay - All Variations
52
1
Time Delay Coarse
129
07,
quantity=1
4
DNP Users Group
P009-0IG.SUB, Version 2.00
REQUEST
RESPONSE
(slave must parse)
(master must parse)
OBJECT
Obj
Var
52
2
Description
Func
Codes
(dec)
Qual
Codes
(hex)
Time Delay Fine
Func
Codes
129
Qual
Codes
(hex)
07,
quantity=1
60
0
60
1
Class 0 Data
1
06
60
2
Class 1 Data
1
06,07,08
60
3
Class 2 Data
1
06,07,08
60
4
Class 3 Data
1
06,07,08
70
1
File Identifier
80
1
Internal Indications
2
00,
index=7
81
1
Storage Object
82
1
Device Profile
83
1
Private Registration Object
83
2
Private Registration Object Descriptor
90
1
Application Identifier
100
1
Short Floating Point
100
2
Long Floating Point
100
3
Extended Floating Point
101
1
Small Packed Binary-Coded Decimal
101
2
Medium Packed Binary-Coded Decimal
101
3
Large Packed Binary-Coded Decimal
No Object
13
No Object
23
(see
4.14)
DNP V3.00 Subset Definitions
P009-0IG.SUB, Version 2.00
5
Chapter 3: LEVEL 3 DNP V3.00
IMPLEMENTATION (DNP - L3)
This chapter describes a subset of the DNP V3.00 Application Layer
which contains more functionality than the Level 2 subset.
3.1 INTENDED USE
This level of implementation of DNP V3.00 is for communicating
between a Master and a medium size slave device (e.g. RTU, Data
Concentrator).
3.2 GENERAL DESCRIPTION
A Level 3 implementation uses a larger range of objects, variations,
function and qualifier codes than a Level 2 implementation.
A Level 3 Slave implementation is the same as a Level 2
implementation with the following additions:
•
•
•
a Level 3 Slave will process read requests for many specific
objects and variations.
a Level 3 Slave will process a larger range of requests with a larger
range of function codes.
A Level 3 implementation supports enabling and disabling unsolicited
responses on a Class-by-Class basis. A Master can enable or disable
unsolicited responses for Class 1, Class 2, and Class 3 objects only.
The request fragment may contain one or more of the following object
headers only (refer to Section 4.2 Data Classes and Events and Section
4.4 Unsolicited Responses ):
-
•
Class 1 (Obj. 60, VAR. 2, Qual. 06)
Class 2 (Obj. 60, VAR. 3, Qual. 06)
Class 3 (Obj. 60, VAR. 4, Qual. 06)
A Level 3 implementation supports the assigning and re-assigning of
data objects to classes dynamically (i.e. during run-time). An ASSIGN
DNP V3.00 Subset Definitions
P009-0IG.SUB, Version 2.00
1
CLASSES (Function Code 22) request will contain a Class 1, 2 or 3
object header followed by one or more static data object headers.
Several sets of Class and data object headers may be contained in a
single request fragment (refer to Section 4.2 Data Classes and Events).
3.3 IMPLEMENTATION TABLE
Table 3.3-1 Describes the objects, function codes, and qualifiers used in a
Level 3 DNP V3.00 implementation. Note that additions and
modifications from implementation Level 2 are shaded.
Table 3.3-1 Level 3 Implementation (DNP-L3)
REQUEST
RESPONSE
(slave must parse)
(master must parse)
OBJECT
Obj
Var
1
0
Binary Input - All Variations
1, 22
00, 01, 06
1
1
Binary Input
1
00, 01, 06
129, 130
00, 01
1
2
Binary Input with Status
1
00, 01 06
129, 130
00, 01
2
0
Binary Input Change - All Variations
1
06,07,08
2
1
Binary Input Change without Time
1
06,07,08
129, 130
17, 28
2
2
Binary Input Change with Time
1
06,07,08
129, 130
17, 28
2
3
Binary Input Change with Relative Time
1
06,07,08
129, 130
17, 28
10
0
Binary Output - All Variations
1
00, 01, 06
10
1
Binary Output
10
2
Binary Output Status
1
00, 01, 06
129, 130
00, 01
12
0
Control Block - All Variations
12
1
Control Relay Output Block
3, 4, 5,
6
17, 28
129
echo of
request
12
2
Pattern Control Block
5, 6
17, 28
129
echo of
request
12
3
Pattern Mask
5, 6
00, 01
129
echo of
request
20
0
Binary Counter - All Variations
1, 7, 8,
9, 10,
22
00, 01, 06
20
1
32-Bit Binary Counter
1
00, 01, 06
129, 130
00, 01
20
2
16-Bit Binary Counter
1
00, 01, 06
129, 130
00, 01
20
3
32-Bit Delta Counter
1
00, 01, 06
129, 130
00, 01
20
4
16-Bit Delta Counter
1
00, 01, 06
129, 130
00, 01
2
Description
Func
Codes
(dec)
Qual
Codes
(hex)
Func
Codes
Qual
Codes
(hex)
DNP Users Group
P009-0IG.SUB, Version 2.00
REQUEST
RESPONSE
(slave must parse)
(master must parse)
OBJECT
Obj
Var
Description
20
5
32-Bit Binary Counter without Flag
20
6
20
Func
Codes
(dec)
Qual
Codes
(hex)
Func
Codes
1
00, 01, 06
129, 130
00, 01
16-Bit Binary Counter without Flag
1
00, 01, 06
129, 130
00, 01
7
32-Bit Delta Counter without Flag
1
00, 01, 06
129, 130
00, 01
20
8
16-Bit Delta Counter without Flag
1
00, 01, 06
129, 130
00, 01
21
0
Frozen Counters - All Variations
1, 22
00, 01, 06
21
1
32-Bit Frozen Counter
1
00, 01, 06
129, 130
00, 01
21
2
16-Bit Frozen Counter
1
00, 01, 06
129, 130
00, 01
21
3
32-Bit Frozen Delta Counter
1
00, 01, 06
129, 130
00, 01
21
4
16-Bit Frozen Delta Counter
1
00, 01, 06
129, 130
00, 01
21
5
32-Bit Frozen Counter with Time of Freeze
21
6
16-Bit Frozen Counter with Time of Freeze
21
7
32-Bit Frozen Delta Counter with Time of Freeze
21
8
16-Bit Frozen Delta Counter with Time of Freeze
21
9
32-Bit Frozen Counter without Flag
1
00, 01, 06
129, 130
00, 01
21
10
16-Bit Frozen Counter without Flag
1
00, 01, 06
129, 130
00, 01
21
11
32-Bit Frozen Delta Counter without Flag
21
12
16-Bit Frozen Delta Counter without Flag
22
0
Counter Change Event - All Variations
1
06,07,08
22
1
32-Bit Counter Change Event without Time
1
06,07,08
129, 130
17, 28
22
2
16-Bit Counter Change Event without Time
1
06,07,08
129, 130
17, 28
22
3
32-Bit Delta Counter Change Event without Time
1
06,07,08
129, 130
17, 28
22
4
16-Bit Delta Counter Change Event without Time
1
06,07,08
129, 130
17, 28
22
5
32-Bit Counter Change Event with Time
22
6
16-Bit Counter Change Event with Time
22
7
32-Bit Delta Counter Change Event with Time
22
8
16-Bit Delta Counter Change Event with Time
23
0
Frozen Counter Events - All Variations
1
06,07,08
23
1
32-Bit Frozen Counter Event without Time
1
06,07,08
129, 130
17, 28
23
2
16-Bit Frozen Counter Event without Time
1
06,07,08
129, 130
17,28
23
3
32-Bit Frozen Delta Counter Event without Time
1
06,07,08
129, 130
17, 28
23
4
16-Bit Frozen Delta Counter Event without Time
1
06,07,08
129, 130
17, 28
23
5
32-Bit Frozen Counter Event with Time
23
6
16-Bit Frozen Counter Event with Time
DNP V3.00 Subset Definitions
P009-0IG.SUB, Version 2.00
Qual
Codes
(hex)
3
REQUEST
RESPONSE
(slave must parse)
(master must parse)
OBJECT
Obj
Var
Description
Func
Codes
(dec)
23
7
32-Bit Frozen Delta Counter Event with Time
23
8
16-Bit Frozen Delta Counter Event with Time
30
0
Analog Input - All Variations
1, 22
00, 01, 06
30
1
32-Bit Analog Input
1
00, 01, 06
129, 130
00, 01
30
2
16-Bit Analog Input
1
00, 01, 06
129, 130
00, 01
30
3
32-Bit Analog Input without flag
1
00, 01, 06
129, 130
00, 01
30
4
16-Bit Analog Input without flag
1
00, 01, 06
129, 130
00, 01
31
0
Frozen Analog Input - All Variations
31
1
32-Bit Frozen Analog Input
31
2
16-Bit Frozen Analog Input
31
3
32-Bit Frozen Analog Input with Time of Freeze
31
4
16-Bit Frozen Analog Input with Time of Freeze
31
5
32-Bit Frozen Analog Input without Flag
31
6
16-Bit Frozen Analog Input without Flag
32
0
Analog Change Event - All Variations
1
06,07,08
32
1
32-Bit Analog Change Event without Time
1
06,07,08
129, 130
17, 28
32
2
16-Bit Analog Change Event without Time
1
06,07,08
129, 130
17, 28
32
3
32-Bit Analog Change Event with Time
32
4
16-Bit Analog Change Event with Time
33
0
Frozen Analog Event - All Variations
33
1
32-Bit Frozen Analog Event without Time
33
2
16-Bit Frozen Analog Event without Time
33
3
32-Bit Frozen Analog Event with Time
33
4
16-Bit Frozen Analog Event with Time
40
0
Analog Output Status - All Variations
1
00, 01, 06
40
1
32-Bit Analog Output Status
1
00, 01, 06
129, 130
00, 01
40
2
16-Bit Analog Output Status
1
00, 01, 06
129, 130
00, 01
41
1
32-Bit Analog Output Block
3, 4, 5,
6
17, 28
129
echo of
request
41
2
16-Bit Analog Output Block
3, 4, 5,
6
17, 28
129
echo of
request
50
0
Time and Date - All Variations
50
1
Time and Date
2 (see
4.14)
07,
1
07,
129
07,
Qual
Codes
(hex)
Qual
Codes
(hex)
quantity = 1
tit
4
Func
Codes
1
DNP Users Group
P009-0IG.SUB, Version 2.00
tit
1
OBJECT
Obj
Var
Description
REQUEST
RESPONSE
(slave must parse)
(master must parse)
Func
Codes
(dec)
Qual
Codes
(hex)
Func
Codes
quantity = 1
50
2
Time and Date with Interval
51
0
Time and Date CTO - All Variations
51
1
Time and Date CTO
Qual
Codes
(hex)
quantity=1
129, 130
07,
quantity=1
51
2
Unsynchronized Time and Date CTO
129, 130
07,
quantity=1
52
0
Time Delay - All Variations
52
1
Time Delay Coarse
129
07,
quantity=1
52
2
Time Delay Fine
129
07,
quantity=1
60
0
Not Defined
60
1
Class 0 Data
1
06
60
2
Class 1 Data
1
06,07,08
20, 21,
22
06
1
06,07,08
20, 21
22
06
1
06,07,08
20, 21
22
06
1
00, 01
60
60
3
4
Class 2 Data
Class 3 Data
70
1
File Identifier
80
1
Internal Indications
2
00,
index=7
81
1
Storage Object
82
1
Device Profile
83
1
Private Registration Object
83
2
Private Registration Object Descriptor
90
1
Application Identifier
100
1
Short Floating Point
100
2
Long Floating Point
100
3
Extended Floating Point
101
1
Small Packed Binary-Coded Decimal
101
2
Medium Packed Binary-Coded Decimal
DNP V3.00 Subset Definitions
P009-0IG.SUB, Version 2.00
5
REQUEST
RESPONSE
(slave must parse)
(master must parse)
OBJECT
Obj
Var
101
3
6
Description
Func
Codes
(dec)
Qual
Codes
(hex)
Func
Codes
Qual
Codes
(hex)
Large Packed Binary-Coded Decimal
No Object
13
No Object
23
(see
4.14)
DNP Users Group
P009-0IG.SUB, Version 2.00
Chapter 4: IMPLEMENTATION
RULES AND
RECOMMENDATIONS
This chapter describes several constraints on the implementation of
DNP V3.00 in addition to those described in the DNP V3.00 Basic 4
Document Set. It defines rules regarding those parts of the protocol
that devices must satisfy in order to conform to any DNP
implementation level. It also makes some recommendations regarding
further behaviour that a device may choose to implement. The purpose
of these additional rules and recommendations is to limit the possible
variations of implementation and encourage standardization.
4.1 ERROR RESPONSES
As a result of the definition of implementation levels, it is necessary
to define the valid responses to a request that either:
•
•
Is not a valid request for the given level, or
Is valid for the given level, but is not applicable to the
particular device.
This section discusses those responses.
4.1.1 Rules
A Slave device may respond to Master requests as described in Table 4.11 if there is an error in the request. The Internal Indication bit numbers
listed are in the second octet.
Response
IIN
bit
Meaning
FUNCTION
UNKNOWN
0
means “My implementation level does not
support this function on objects of this group
and variation”.
OBJECT
UNKNOWN
1
means either “My implementation level does
not support this group and variation of
object”, or for static objects, “I have no
DNP V3.00 Subset Definitions
P009-0IG.SUB, Version 2.00
1
Response
IIN
bit
Meaning
objects with this group and variation”. Cannot
be used as a response for event objects if the
request is defined for the level. In that case,
the Slave must send a Null Response (see
below).
PARAMETER
ERROR
2
means “I have objects of this group and
variation, but not within the range of points
specified”. This IIN bit must be set even if some
of the points specified are available. In such a
case, the Slave may choose to include in the
response those objects that are available, but
this behaviour is not mandatory. Not permitted
if no range was specified.
Null Response
(no IIN bits set,
but no objects
of the
specified type
returned)
n/a
means “No point range was specified, and I
have no objects of this type”. Primarily used in
response to event data polls. Can be used
instead of OBJECT UNKNOWN for static objects
if no range was specified.
Table 4.1-1 Valid Error Responses
Event objects are treated differently than static objects because they are not
tied to physical hardware. They may not exist on a device at any given
moment, even though the device is able to report them.
4.2 DATA CLASSES AND EVENTS
Many static data points (eg. binary input, analog input) within a Slave
device can generate DNP event objects (eg. Binary Input Change With
Time, Analog Input Change Event). This section describes the interaction
between data points, event objects and DNP data classes.
4.2.1 Rules
If a Slave device reports event objects, it must designate each of its data
points as generating either Class 1, Class 2 or Class 3 event objects by
default. (This designation may be configurable). The Class of event data is
therefore an attribute of the data point and the event objects the data point
reports. Every event object reported by the Slave device therefore belongs to
Class 1, Class 2 or Class 3. Every static object reported by the Slave device
belongs to Class 0.
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Level 3 Slave devices must permit a Master to enable or disable the
reporting of event objects by making ASSIGN CLASS (function code 22)
requests.
To enable the reporting of event objects for a particular data point, the
Master specifies in its ASSIGN CLASS request a Class 1, 2 or 3 object
header and the header of a static object for the appropriate data point.
For example, to enable the generation of Class 2 events from DNP analog
input point 4, the Master device sends an ASSIGN CLASS request
containing the following object headers:
•
•
Class 2 (Obj. 60 , Var. 3)
Analog Input (Obj. 30, Var. 0, Index 4)
Such a request does not mean the static object now belongs to Class 2;
static objects belong to Class 0 by definition. Instead, the static object
represents the data point itself, and the request means all event objects
generated by the data point will belong to the specified Class.
A Master device tells a Slave device to stop reporting event objects for a
particular data point by assigning event objects from the data point to Class
0. Since Class 0 is the class of static data and event objects cannot be Class
0, the Slave will not produce any further event objects for the data point.
The actual event object the Slave device reports after the Master device
enables event object reporting will vary depending on the request of the
Master.
The Master may request event objects by sending:
•
a READ request for specific objects (eg. a READ request for Binary
Input Change With Time objects, or a READ request for 16-Bit Analog
Input Change Event Without Time objects).
•
a READ request for a class of objects (eg. a READ request for Class 2
data). The Slave device returns all event objects assigned to the Class.
•
a READ request for a quantity of Class objects (eg. a READ request of
Class 2 data, specifying a quantity of 20 objects. The Slave returns the
first 20 event objects it collected that were assigned to Class 2).
•
a READ request for several Classes of data (eg. a READ request
containing both Class 1 and Class 2 object headers).
A particular implementation level may support only certain methods of
reading data. Refer to the appropriate chapters to determine whether a
particular method is valid for a given implementation level.
If a Master does not specify a particular variation of object (i.e. when
requesting a Class of data or requesting variation 0 of any object), the Slave
DNP V3.00 Subset Definitions
P009-0IG.SUB, Version 2.00
3
reports the default variation of object for the data point. This default
variation may be configured.
If a Master READs several Classes of data in the same request, the Slave
must not group the event objects by Data Class in its response. In particular,
the Slave must report Binary Change events within a response in the order
the events occurred. For example, consider a Slave device that detects the
following events, in the order listed:
•
•
•
•
Binary Input Change Without Time point 3 - Class 3
Binary Input Change Without Time point 1 - Class 3
Binary Input Change Without Time point 6 - Class 1
Binary Input Change Without Time point 2 - Class 3
If the Master device sends a single READ request asking for Class 3, Class
2 and Class 1 data, the Slave must return the events in the order listed
above. The Slave must NOT send all the Class 3 events together before
sending the Class 1 event.
4.2.2 Recommendations
It is highly recommended that all Slave devices report event data and that all
Masters provide a report-by-exception mode of operation. This is only a
recommendation because although DNP-L1 specifies Masters must be able
to parse certain event objects, it does not specify that the Master necessarily
uses them or that the Slave necessarily reports them. A particular
combination of Master and Slave implementations will be interoperable
even if event data are not supported. However, the combination may not be
efficient or useful, as discussed below.
DNP is a relatively high-overhead set of protocols compared to its
predecessors; however, the bandwidth available to most utility companies is
still quite limited. Therefore, efficient bandwidth usage is vital to market
acceptance of a particular DNP implementation. DNP provides several
different means of retrieving data. They are listed here from most to least
efficient:
1. Quiescent Operation, in which the Master never polls any Slave, and all
communication is unsolicited report-by-exception. The Master still
sends application layer confirmations to the Slave.
2. Unsolicited Report-by-Exception Operation, in which most
communication is unsolicited, but the Master occasionally sends
integrity polls for Class 0 Data to verify its database is up to date.
3. Polled Report-by-Exception Operation, in which the Master polls
frequently for event data and occasionally for Class 0 Data. Most often
the Slave’s response to the event polls will contain few objects, so
polling can be very quick. The response size can be further limited if the
Master requests a maximum number of events (qualifiers 0x07, 0x08).
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4. Polled Static Operation, in which the Master polls only for Class 0 data
or the specific data it requires. This method is the simplest to implement,
but can be very inefficient if the number of points that need to be
retrieved is high and changes are infrequent.
Some systems may also choose to mix Polled and Unsolicited Report-byException operation.
Given that unsolicited responses are not always possible using some
physical layers, the recommended minimum implementation for a Slave is
Polled Report-by-Exception Operation. The Subset Definitions have been
written with this in mind.
They have also been written with the goal that all data from a Slave be
accessible using the least bandwidth and the least parsing required by the
Slave. Therefore frequent polls of Class 1, 2, and or 3 Data, interspersed
with occasional integrity polls of Class 0 Data, is the recommended
minimum implementation.
4.3 SLAVE DEVICE START-UP
4.3.1 Rules
Upon start-up of a Slave device, the Slave device must set true(1) the
DEVICE RESTART Internal Indication bit within the Internal Indication
field of each subsequent response and unsolicited response. This bit must
remain set until a Master device clears it with a WRITE request.
If the Slave device is configured to send unsolicited responses, it must
immediately send an unsolicited response upon start-up. This initial
unsolicited response must contain either:
•
the response header only, containing the Access Control, Function Code
and IIN fields.
•
the response header plus the current state of ALL of its static data points
(eg. binary inputs, analog inputs).
The initial unsolicited response may also contain any events objects the
Slave device had generated while running previously, but had not yet
reported to the Master. If such objects exist, the Slave must report them
before the static data. This rule allows the Master to report data changes in
chronological order by simply parsing the message from beginning to end
(i.e. the most recent value of any point will be the last one reported in the
message).
The vendor of the device must specify in a Device Profile Document
whether the device sends unsolicited responses, and if so, whether it
DNP V3.00 Subset Definitions
P009-0IG.SUB, Version 2.00
5
includes static data in the initial unsolicited response. Refer to APPENDIX
A: DEVICE PROFILE DOCUMENT FORMAT for more details
regarding the Device Profile Document.
Upon receiving this initial unsolicited response, the Master device must
send a WRITE request to clear the DEVICE RESTARTED Internal
Indication object reported by the Slave.
4.3.2 Recommendations
If a Slave device does not automatically report all of its static data in an
initial unsolicited response, the Master device should immediately poll for
all of the device's event data and static data (ie. send a READ request for
Class 1, Class 2, Class 3 and Class 0 data).
4.4 UNSOLICITED RESPONSES
4.4.1 Rules
A Slave device may optionally send unsolicited responses to a Master
device. The vendor of a Slave device must specify in a Device Profile
Document whether the device can send unsolicited responses. This
document must also specify which objects, variations, qualifiers and
function codes the Slave device may include in those unsolicited responses.
Refer to APPENDIX A: DEVICE PROFILE DOCUMENT FORMAT
for more details regarding the Device Profile Document.
All Slave devices must provide a mode of operation in which the Slave
never sends unsolicited responses. This mode of operation must be
configurable.
The ability to configure unsolicited responses for the entire device is
separate from the ability of the Master to disable unsolicited responses using
requests. The following rules apply:
1. If a Slave device is configured to send unsolicited responses, a Master
device may disable unsolicited responses by sending a DISABLE
UNSOLICITED request (function code 22).
2. If a Slave device is configured to send unsolicited responses, it must
send an initial unsolicited response upon start-up regardless of whether
the Master sent any DISABLE UNSOLICITED requests (See Section
4.3: Slave Device Start-up for details). This rule ensures the Master
device is notified immediately if the device restarts. The rule applies
even if the Master has disabled unsolicited responses from all points on
the Slave device.
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Slave devices implementing Level 2 or greater may report static data objects
in unsolicited responses. They may do so only under the following
conditions:
•
•
upon start up of the Slave device.
when the status flags of points (within the flag octet) change state. For
example, if a range of analog inputs go off-line, then 16-Bit Analog
Input objects may be reported in an unsolicited response.
All other events or exceptions must be reported using event data objects.
The destination address of the Master device to which the unsolicited
responses are sent must be configurable in the Slave device.
All levels of Master devices must support unsolicited responses.
4.5 OPERATING BINARY OUTPUTS
4.5.1 Rules
All Slave devices must be able to parse operations on Control Relay Output
Block objects (Obj.12, Var.1) for operating binary outputs. If a Slave device
does not actually have any binary output points, it may respond with the
PARAMETER ERROR or OBJECT UNKNOWN Internal Indications set.
The FUNCTION UNKNOWN Internal Indication is not a valid response in
this case.
Similarly, a Slave device must parse all output function codes (e.g.
SELECT/OPERATE) and control types (e.g. PULSE ON). If the Slave does
not choose to implement a particular function code or control type, it must
not respond with FUNCTION UNKNOWN. It must respond with the value
operation not supported in the STATUS field of the Control Relay Output
Block.
The control operations supported by a Slave device must be described in the
Device Profile Document for the device. Refer to APPENDIX A:
DEVICE PROFILE DOCUMENT FORMAT for more details.
4.5.2 Recommendations
The use of WRITEs to Binary Output objects (Obj. 10, VAR. 1) as a means
of operating binary outputs is not recommended because the response to a
WRITE request cannot give an indication of whether the operation was
successful.
If a Slave device implements WRITEs to Binary Outputs in addition to
operations on Control Relay Output Blocks, it is recommended that the
device “loop back” the state of each output to a Binary Input object. This
will provide some feedback to the Master.
DNP V3.00 Subset Definitions
P009-0IG.SUB, Version 2.00
7
!
NOTE:
Control Relay Output Block object index x and
Binary Output object index x both refer to the same physical
binary output point.
It is recommended that whenever possible, Slave devices behave in a “don’t
care” manner regarding which output operations they support. In other
words, if security is not a major issue and the device’s hardware does not
require specific instructions, the Slave device should accept as many control
types (LATCH, PULSE, TRIP/CLOSE etc.) as possible.
It is recommended that if possible, all output points on a particular Slave
device support the same output function codes, to reduce the complexity of
configuration for Masters.
4.6 FRAGMENTS AND FRAMES
4.6.1 Rules
Devices must not transmit application layer fragments larger than 2048
bytes, unless the fragment size is configurable and can be limited to 2048
bytes.
All devices must accept application layer fragments of 249 bytes or fewer.
All devices must accept maximum size data link layer frames (292 bytes).
A Master device must not send multi-fragment requests.
A Master device must accept multi-fragment responses.
A Slave device must be able to return all of its data (static and event) within
a single response. In other words, a response to a READ request for Class 1,
Class 2, Class 3 and Class 0 data must fit into a single response. A single
response may consist of one or more fragments.
The maximum frame size transmitted, the maximum fragment size
transmitted, and whether or not a Slave device sends multi-fragment
responses must be documented in the Device Profile Document for the
Slave device. Refer to APPENDIX A: DEVICE PROFILE
DOCUMENT FORMAT for more information regarding Device Profile
Documents.
4.6.2 Recommendations
It is recommended that the maximum size of a fragment be configurable in
both Slave devices and Master devices.
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It is recommended that Master devices choose the qualifiers and objects in
their requests so as to minimize the amount of bandwidth required.
4.7 MULTIPLE OBJECTS IN A SINGLE REQUEST
4.7.1 Rules
All Slave devices of all levels must be able to parse a single Master request
containing any subset of all of the objects the Slave device supports. For
example, a Level 2 Slave implementation must be able to parse a single
READ request containing one or more of the following objects:
•
•
•
•
Class 0 data
Class 1 data
Binary Counter - All Variations
Binary Input Change With Time, quantity 20
4.8 MULTIPLE OBJECTS IN A SINGLE RESPONSE
4.8.1 Rules
All Master devices must be able to parse a single Slave response or
unsolicited response containing any subset of the objects the Master device
supports. For example, it must be able to parse a single response containing
Binary Input, Analog Input, Counter Input and Binary Output Status objects.
4.9 CONFIRMATION AND RETRIES
4.9.1 Rules
All levels of Slave and Master devices may choose when they request
confirmation of outgoing data link frames. Whether a device always, never
or sometimes (e.g. only when configured, only for certain messages)
requests data link CONFIRM frames must be documented in the Device
Profile Document for the device. Refer to APPENDIX A: DEVICE
PROFILE DOCUMENT FORMAT for more information regarding
Device Profile Documents.
A Slave or Master device must transmit a data link CONFIRM frame if it is
requested to do so by a SEND/CONFIRM EXPECTED function code an
incoming frame.
A Slave or Master device must transmit an Application Layer Confirmation
Response if it is requested by the CONFIRM bit in an incoming fragment.
If a Slave is waiting for an application layer confirmation to a Response
(function code 129) and receives a new request instead, it must:
DNP V3.00 Subset Definitions
P009-0IG.SUB, Version 2.00
9
1. Assume the confirmation will not be forthcoming and therefore retain
any event data for the next request.
2. If the new request asks for some of the unconfirmed event data, include
this data in the response.
3. Process and respond to the new request.
This rule ensures controls and other vital operations will receive priority
over any operation pending at the Slave, such as a response to a READ
request.
It also ensures the Master retains control over any polling sequence. This
rule is implied in the DNP V3.00 Application Layer specification, but not
explicitly stated.
As described in section 3.3 of the DNP V3.00 Application Layer, this rule
also applies to Unsolicited Responses (function code 130), with one
exception. For READ requests, PROCESS_AFTER_CONFIRM mode
applies: the Slave does not respond to the READ until it has received
confirmation for its Unsolicited Response. This rule remains unchanged
from the DNP V3.00 Application Layer, because it prevents the same event
data from being sent to the master twice, once in the Unsolicited Response,
once in the READ Response.
If a Slave device supports application layer retries, the number of retries
performed must be configurable and be disabled by default. This provision
allows Master devices to choose application response timeouts as needed by
the overall network, without needing to account for retries by any particular
Slave.
4.9.2 Recommendations
It is recommended that enabling or disabling Data Link Confirms be
configurable in both Slave devices and Master devices. This practice is
recommended because the use of data link CONFIRM frames, across a
highly reliable point to point physical media, can effectively halve
communication throughput.
It is recommended that a Slave device only requests Application Layer
Confirmation Responses:
•
on outgoing fragments that contain event data. This allows the Slave
device to be sure the Master has received the event objects, and the
Slave can therefore remove them from its internal buffers if it chooses.
•
on large outgoing multi-fragment messages, in particular File Identifier
Objects. This permits the Master to perform application-layer flow
control, since the Master may take a significant amount of time to
process large messages.
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DNP Users Group
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•
when a particular IIN or status flag must be acted upon by the Master,
e.g. Roll-Over or Buffer Overflow.
It is recommended that if a Slave device implements application layer
retries, it only does so for unsolicited responses. Application layer retries
are not especially useful for ensuring reliability in solicited responses
because:
•
•
•
•
The data link layer may already have performed several retries.
Data link layer retries are more efficient because they only re-transmit
part of the application layer message.
If the Master does not receive the data, it can retry the request.
If the Slave performs application layer retries, the Master must account
for this in its application response timeout, which may affect system
performance.
However, using application retries for unsolicited responses is more useful
because:
•
•
The Master was not expecting the data, so it will not need to account for
the retry in any timeout.
Because the Master was not expecting the data, it cannot cause the Slave
to resend the data as with solicited responses.
Conformance or otherwise to these recommendations must be documented
in the Device Profile Document for the Slave device.
It is recommended that a Master device does not request Application Layer
Confirms on outgoing fragments. Application Layer Confirmation
Responses are not usually needed for requests because most requests require
a response from the Slave device. The Application Layer Confirmation
Response is redundant.
Conformance or otherwise to this recommendation must be documented in a
Device Profile Document for the Master device.
4.10 WITH-FLAG AND WITHOUT-FLAG VARIATIONS
4.10.1 Rules
A Slave device may choose to return an object containing a flag (e.g. 16-Bit
Analog Input) when the Master has requested a without flag object variation
(e.g.. 16-Bit Analog Input Without Flag). Similarly, a Slave may choose to
return an object variation without a flag when the Master has requested an
object variation with a flag. Whether or not the Slave device responds with
an object containing a flag is the Slave's decision. The lack of a flag in an
object implicitly implies that the flag = 1 (i.e. the point is on-line and no
other exceptions are occurring).
DNP V3.00 Subset Definitions
P009-0IG.SUB, Version 2.00
11
A Master device must be able to process responses containing object
variations both with flags and without flags.
4.11 16-BIT AND 32-BIT VARIATIONS
4.11.1 Rules
A Slave device chooses a default object variation to report in response to a
READ request for a Class of data, or for variation 0 of a particular object.
For example, a Slave may choose to report a counter input as either a 16-bit
or 32-bit variation, depending on an internal default or on the Slave device's
configuration. If, however, a Master device explicitly requests a particular
variation, the Slave device must respond with a particular variation.
!
NOTE:
There is one exception to this rule. The choice of
whether or not to use a with flag or without flag variation is
nonetheless up to the Slave device. See Section 4.9.2: WithFlag and Without-Flag Variations. However, the chosen
variation must be the size the Master requested.
4.11.2 Rules for Analog Inputs and the OVER-RANGE
Flag
Some analog input data gathered by a Slave device may be inherently a
certain size (e.g. if the Slave's A/D convertors provide only 12 bits of
resolution). However, a Master device may request this data in any size,
either 16-bit or 32-bit. The following rules govern how to report this type of
data:
1. If a Master requests a particular object variation (e.g. 16-bit Analog
Input), and the measured value of the data point within the Slave device
is within the range for the DNP variation (e.g. within 32767 to -32767),
then the Slave reports the value without modification within the
requested variation.
!
NOTE:
For a data value stored within the device as (for
example) a 12-bit two's complement number, this procedure
will simply involve sign extending the value to its 16-bit or
32-bit two's complement representation. Since DNP analog
values are signed, sign extension is not considered a
modification of the value.
2. If a Master requests a 16-bit variation and the value of the data point is
outside of the range 32767 (7FFF hex) to -32768 (8000 hex), then the
Slave reports the value as either 32767 or -32768. The Slave device sets
the Over-Range bit within the flag field of the object.
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3. If a Master requests a 32-bit variation and the value of the data point is
outside of the range 2147483647 (7FFF FFFF hex) to -2147483648
(8000 0000 hex), then the Slave device reports the value as either
2147483647 or -2147483648. The Slave device sets the Over-Range bit
within the flag field of an object.
4. If an input exceeds the range measurable by the hardware on the Slave
device, the Slave device sets the Over-Range bit within the flag field of
the object. It does not alter the value reported by its hardware. For
example, a Slave device with a 12-bit A/D converter must set the OverRange bit when the measured value exceeds 2047. The Slave device
must still report the value as 2047 in the analog input object.
Table 4.11-1 illustrates these rules. The Slave sets the Over-Range flag in
each case described in the table, except the example of 33000 requested as a
32-Bit Analog Input. This is a case of Rule #2 applying, but not Rule #3.
Size Stored Internally
by the Device (size of
A/D convertor)
8 bits
12 bits
16 bits
32 bits
Measured Value
Response to a
Request for 16-bit
Analog Inputs
Response to a
Request for 32-bit
Analog Inputs
> +127
007F
0000007F
< -128
FF80
FFFFFF80
> +2047
07FF
000007FF
< -2048
F800
FFFFF800
> +32767
7FFF
00007FFF
< -32768
8000
FFFF8000
> +2147483647
7FFF
7FFFFFFF
33000 (example)
7FFF
00080E8 *
< -2147483648
8000
80000000
* Over-Range flag is not set in this case. Over-Range is set in all other cases.
!
•
Table 4.11-1 Examples of Over-Range Conditions and Values
NOTE:
The DNP V3.00 Object Library makes certain
statements that may appear to contradict these rules. There is
no contradiction, as explained below.
When a Slave returns a 16-bit Analog Input object and the Over-Range
bit is set, the DNP V3.00 Data Object Library states, "The actual value
field can be ignored [by the Master device] as its value is not defined."
This rule holds; therefore, the "rules" listed in this section for 16-bit
Analog Inputs are actually recommendations, since a Master may ignore
the value of the object.
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13
•
When a Slave returns a 32-bit Analog Input object, the DNP V3.00 Data
Object Library states, "The actual value will be +231-1 or -231 if it is
over-range or under-range." This rule also holds, but only describes the
cases in which the Slave represents the object in 32 bits internally.
4.11.3 Rules for Counter Objects and the ROLL-OVER
Flag
The Roll-Over flag in counter objects is not a useful flag because of DNP’s
flexibility in reporting object variations. A Master device has no way of
determining whether the counter rolled over at 16-bits, 32-bits, or some
internal value. Unlike the case of the Over-Range flag for Analog Inputs, a
Binary Counter object cannot be reported at its maximum value to indicate
the device’s internal maximum range. The counter must continue
incrementing after being set to zero, or information will be lost. Therefore
the following rules apply:
1.
Slave devices may choose not to set the Roll-Over flag.
2.
The Device Profile Document for a Slave device must identify the
point at which the Slave device’s counters roll over. Refer to
APPENDIX A: DEVICE PROFILE DOCUMENT FORMAT for
more information regarding Device Profile Documents.
3.
The Device Profile Document for a Slave device must identify the
default size of counter the Slave reports when asked for Class Data
or Variation 0. This default size does not change unless the Slave
device is re-configured.
4.
If a Slave responds to both 16-bit and 32-bit requests, the Slave must
respond with the lower 16 bits of a 32-bit counter when asked for 16
bits.
5.
If a polled mode of data reporting is used, it is the responsibility of
the Master to poll often enough to capture any roll-over condition
that occurs.
4.11.4 Recommendations Regarding the ROLL-OVER
Flag
It is highly recommended that Slave devices do not set the Roll-Over flag,
for the reasons discussed in the previous section.
It is highly recommended that Master devices ignore the Roll-Over flag.
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4.12 TIME TAGGED BINARY INPUT EVENTS
4.12.1 Rules
Slave devices must preserve the sequence of occurrence of binary input
event objects within responses. For instance, Binary Input Without Time
objects (Obj. 2, VAR. 2) must be returned in the sequence in which they
occur.
If a Master device does not specify a particular variation of binary input
event object in a READ request, a Slave may choose what variation to
report. If a Master requests a particular Class of data, or a request for Binary
Input Change Events with variation 0, a Slave may choose to report, for a
given event:
•
only a time-tagged event object, i.e. either Binary Input Change With
Time or Binary Input Change With Relative Time.
•
only a Binary Input Change Without Time event object.
•
both a Binary Input Change Without Time object and one of the timetagged binary event objects from the same event. If the Slave device
implements this option, it must be configurable so the user can disable
the reporting of one variation or the other.
The manner in which a Slave device reports binary input event objects must
be described in the Device Profile Document for the Slave device. The
manner in which a Master device expects binary input event objects to be
reported must be described in its Device Profile Document. Refer to
APPENDIX A: DEVICE PROFILE DOCUMENT FORMAT for
details.
If a Master device requests a specific variation of binary input event object,
the device must report that variation. For instance, if the Slave receives a
READ request for Binary Input Change With Relative Time (Obj.2, VAR.
3), it must respond with data in the requested variation.
4.12.2 Recommendations
Whenever a Slave responds with Binary Input Change With Relative Time
objects (Obj.2, VAR.3), the objects are preceded by either a Time and Date
CTO (Obj.51, VAR.1) or an Unsynchronized Time and Date CTO (Obj.51,
VAR.2) object. It is recommended that the Unsynchronized Time and Date
CTO object be used if the Slave's Time and Date have not been set.
4.13 FREEZE OPERATIONS
This section clarifies the use of the various FREEZE function codes. Upon
receiving a FREEZE request, a Slave device must copy the appropriate
Binary Counter values ("running" counters) into a "freeze" buffer. The
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15
Master may read these frozen values as Frozen Counter Input objects (Obj.
21). If a FREEZE AND CLEAR request is being processed, the Slave must
clear the “running” values immediately after performing the FREEZE. A
READ request of Binary Counter Input objects (Obj. 20) always return the
values of the "running" counters.
4.13.1 Rules
A Master device must perform FREEZE operations on Binary Counter
objects (Obj. 20) only, NOT on Frozen Counter objects (Obj. 21).
If a Level 2 or Level 3 Slave device supports Binary Counter objects, it
must support FREEZE operations (it cannot return an error response).
However, it need not support READs of Frozen Counter objects if it
chooses not to. This is allowed because the DNP V3.00 Data Object Library
states “Point i in obj 20 and point i in obj 21 are NOT necessarily the same
point”. Therefore, not all Binary Counters must have corresponding Frozen
Counters.
4.14 TIME SYNCHRONIZATION
4.14.1 Rules
A Slave device need not support WRITE operations on Time and Date
objects or support DELAY MEASUREMENT requests if it never sets the
TIME SYNCHRONIZATION REQUIRED Internal Indication bit in its
responses or unsolicited responses.
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Chapter 5: CONFORMANCE
This Chapter specifies the functions a Master or Slave device must
support in order to conform to a defined implementation level.
The subset definitions deal primarily with the application layer of the
DNP V3.00 protocol. It is nevertheless a requirement that in order for a
device to conform to an implementation level, it must have implemented
on it services of the Data Link Layer and Transport Functions (as
defined in the DNP V3.00 Basic 4 Document Set) sufficient to support
the implementation level. For instance, all subsets require a Slave device
support Class 0 Data polls; if the response to such a poll would exceed
249 octets, segmentation by the Transport Function must be supported.
5.1 SLAVE DEVICES
In order for a Slave device to implement a particular Level “X” of DNP
V3.00, the device must conform to the following:
•
The Slave device must be able to parse all Master requests defined
for Level “X”.
•
The Slave device must be configurable to not transmit anything other
than Level “X” responses to Level “X” requests.
•
The Slave device must obey all of the implementation rules defined
in Chapter 4.
•
The vendor must describe the device's DNP implementation in a Device
Profile Document and make this document available to users of the
device.
The Device Profile Document consists of a form, an implementation table
similar to those found in this document, and some optional accompanying
text. See APPENDIX A : DEVICE PROFILE DOCUMENT FORMAT
for details.
A Slave device may accept and respond to additional requests not defined in
Level “X” and still conform to that level. It may respond to such requests
with data not defined in Level “X”.
Any additional functions the Slave provides must not prevent a Master
device from communicating with a Slave device on the defined level. For
instance, a DNP-L1 Slave may choose to accept WRITE requests of File
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1
Identifier Objects. However, it must not require a Master to send such a
request in order to operate.
5.2 MASTER DEVICES
In order for a Master device to implement a particular level “X” of DNP
V3.00, the device must conform to the following:
•
•
•
•
The Master device must be able to parse all Slave responses defined for
Level “X”.
The Master device must be configurable to limit the requests it sends to
Slave devices with implementation levels lower than “X”. For instance,
a Level 3 Master must be configurable so it does not send any requests
to either a Level 1 Slave or a Level 2 Slave that they could not parse.
This does not prevent the Master from sending Level 3 requests to a
Level 3 Slave.
The Master device must obey all of the implementation rules defined in
Chapter 4.
The vendor of the Master device must describe the device's DNP
implementation in a Device Profile Document and make this document
available to users of the device.
The Device Profile Document consists of a form, an implementation table
similar to those found in this document, and some optional accompanying
text. See APPENDIX A : DEVICE PROFILE DOCUMENT FORMAT
for details.
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Appendix A: DEVICE PROFILE
DOCUMENT FORMAT
Vendors must produce a Device Profile Document for each device they
manufacture implementing DNP V3.00. The Device Profile Document clearly
identifies any deviations from the implementation subsets described in this
document and any other issues that may arise when determining the device's
compatibility with another device. The Device Profile Document addresses
Application Layer and Data Link Layer issues only; the Physical Layer is not
addressed because of the multitude of different layers and configurations
possible.
! NOTE:
Do not confuse the Device Profile Document with the Device
Profile Object defined in the DNP V3.00 documentation. The
Device Profile Object does not at present contain sufficient
information to establish compatibility between two devices. It
must be modified in the future to include some of the
information found in the Device Profile Document.
This appendix describes the minimum information that a vendor must include
in the Device Profile Document.
Implementation
Table
A table similar to those found in this document, identifying which
object variations, function codes and qualifiers the device supports
in both requests and responses, e.g.
OBJECT
Obj
Var
30
4
REQUEST
Description
16-Bit Analog Input without Flag
RESPONSE
Func
Codes
Qual
Codes
(hex)
Func
Codes
Qual
Codes
(hex)
1
00, 01, 06
129, 130
01
......
The Request columns identify all requests sent by a Master device,
or all requests parsed by a Slave device. The Response columns
DNP V3.00 Subset Definitions
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1
identify all responses parsed by a Master device, or all responses
sent by a Slave device. If the device does not actually use all the
requests or responses that it can parse, attach notes (or add
columns) to the Implementation Table identifying which are not
used.
Point List
Description
This is an optional part of the Device Profile Document. Some
vendors of Slave devices may wish to include a list of the data
points provided by the device. The format of this list is optional,
but the following is suggested:
Index
Default Static Variation
Default Event Variation
Obj
Var
Desc
O
b
j
Var
Class
Point Name
Desc
Binary Input
7
1
1
No Status
2
1
2
Without
Time
Breaker 'A' Tripped
Analog Input
3
30
1
32-bit
3
2
3
1
32-Bit
Without
Time
Phase 1 VARs
Vendor Name
The name of the organization producing the device.
Device Name
The model and name of the device, sufficient to distinguish it from
any other device from the same organization.
Highest DNP Level
Supported
The highest-numbered DNP implementation subset to which the
device completely conforms.
Device Function
Either Master or Slave. Masters send DNP requests, while Slaves
send DNP responses. If a single physical device can perform both
functions, supply a separate Device Profile Document for each
function.
Notable Additions
A brief description intended to quickly identify for the reader the
most obvious features the device supports in addition to the
Highest DNP Level. The complete list of features is described in the
Implementation Table.
Maximum Data Link
Frame Size
The largest size of Data Link Frame the device transmits, in octets.
Maximum Fragment
Size
The largest size of Application Layer fragment the device transmits,
in octets.
Maximum Data Link
The number of times the device will re-transmit a confirmed data
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Re-tries
link frame before aborting the transaction.
Maximum
Application Re-tries
The number of times the device will re-transmit a confirmed
application request or response before aborting the transaction.
Requires Data Link
Confirmation
Whether the device ever transmits SEND/CONFIRM EXPECTED
- USER DATA frames.
Requires Application Whether the device ever sends application layer messages with the
Confirmation
CONFIRM bit set in the APPLICATION CONTROL field.
Timeouts
The time conditions under which the device will discard an
incoming frame, fragment, request or response.
Control Operations
The control operations permitted by the device. A device may
support an Analog Output or Control Relay Output Block, but not
necessarily support all operations on that object.
Reports Binary Input A description of what variation of objects a Slave device reports
Change Events
when asked for Binary Input Change events with variation 0 or
when asked for Class data. Refer to subset document section 4.12
Time-Tagged Binary Input Events.
Sends Unsolicited
Responses
A list of the conditions under which a Slave device sends
unsolicited responses.
Sends Static Data
Unsolicited
A list of the conditions under which a Slave device sends static data
(Class 0) as unsolicited responses.
Default Counter
Object/Variation
The object and variation a Slave Device uses to report counter
objects when asked for Variation 0 or for Class data. See subset
document section 4.11.3.
Counters Rollover
At
The value at which a Slave device’s counters roll over. See subset
document section 4.11.3.
Sends MultiFragment Responses
Yes or No; whether a slave device sends multi-fragment responses
(Master devices do not send multi-fragment requests)
A blank device profile form follows. The form must be accompanied by an
Implementation Table and may optionally be accompanied by a Point List. A
vendor may check multiple boxes within a section. Vendors of Master devices may
optionally include text explaining under what conditions the Master device sends
each type of request, e.g.: polling rates and methods, etc. This information is
optional but may aid vendors of Slave devices in being compatible with the Master
device.
In general, if a vendor checks a box marked "Configurable", the vendor must
DNP V3.00 Subset Definitions
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3
attach an explanation of how an item can be configured. The format of such an
explanation is optional, but might answer some of the following questions:
"
"
"
"
At the factory, or in the field?
Using what equipment?
Over what range is the item configurable?
Under what conditions?
Similarly, if the vendor checks a box marked "Variable" or "Sometimes", the
vendor must attach more details explaining under what conditions the specified
item will occur.
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DNP Users Group
P009-0IG.SUB, Version 2.00
DNP V3.00
DEVICE PROFILE DOCUMENT
This document must be accompanied by a table having the following headings:
Object Group
Request Function Codes
Response Function Codes
Object Variation
Request Qualifiers
Response Qualifiers
Object Name (optional)
Vendor Name:
Device Name:
Highest DNP Level Supported:
Device Function:
# Master
For Requests
# Slave
For Responses
Notable objects, functions, and/or qualifiers supported in addition to the Highest DNP Levels Supported
(the complete list is described in the attached table):
Maximum Data Link Frame Size (octets):
Transmitted __________________
Received
Maximum Application Fragment Size (octets):
Transmitted ________ (if >2048, must
be configurable)
(must be 292)
Received
Maximum Data Link Re-tries:
# None
# Fixed at _______________________
DNP V3.00 Subset Definitions
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________ (must be > 249)
Maximum Application Layer Re-tries:
# None
# Configurable, range ____ to _______
5
# Configurable, range ____ to _______
(Fixed is not permitted)
Requires Data Link Layer Confirmation:
# Never
# Always
# Sometimes
If 'Sometimes', when? __________________________________________
# Configurable If 'Configurable', how? ______________________________________________
Requires Application Layer Confirmation:
# Never
# Always (not recommended)
# When reporting Event Data (Slave devices only)
# When sending multi-fragment responses (Slave devices only)
# Sometimes
If 'Sometimes', when? ___________________________________________
# Configurable If 'Configurable', how? ______________________________________________
Timeouts while waiting for:
Data Link Confirm
Complete Appl. Fragment
Application Confirm
Complete Appl. Response
# None
# None
# None
# None
# Fixed at _________
# Fixed at _________
# Fixed at _________
# Fixed at _________
# Variable
# Variable
# Variable
# Variable
# Configurable
# Configurable
# Configurable
# Configurable
Others
__________________________________________________________________________
Attach explanation if 'Variable' or 'Configurable' was checked for any timeout
Sends/Executes Control Operations:
WRITE Binary Outputs
# Never
# Always # Sometimes # Configurable
SELECT/OPERATE
# Never
# Always # Sometimes # Configurable
DIRECT OPERATE
# Never
# Always # Sometimes # Configurable
DIRECT OPERATE - NO ACK # Never
# Always # Sometimes # Configurable
Count > 1
Pulse On
Pulse Off
Latch On
Latch Off
# Never
# Never
# Never
# Never
# Never
# Always
# Always
# Always
# Always
# Always
# Sometimes
# Sometimes
# Sometimes
# Sometimes
# Sometimes
# Configurable
# Configurable
# Configurable
# Configurable
# Configurable
Queue
Clear Queue
# Never
# Never
# Always
# Always
# Sometimes
# Sometimes
# Configurable
# Configurable
Attach explanation if 'Sometimes' or 'Configurable' was checked for any operation.
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FILL OUT THE FOLLOWING ITEM FOR MASTER DEVICES ONLY:
Expects Binary Input Change Events:
# Either time-tagged or non-time-tagged for a single event
# Both time-tagged and non-time-tagged for a single event
# Configurable (attach explanation)
FILL OUT THE FOLLOWING ITEMS FOR SLAVE DEVICES ONLY:
Reports Binary Input Change Events when no
specific variation requested:
# Never
# Only time-tagged
# Only non-time-tagged
# Configurable to send both, one or the
other (attach explanation)
Sends Unsolicited Responses:
# Never
# Configurable (attach explanation)
# Only certain objects
# Sometimes (attach explanation)
Reports time-tagged Binary Input Change Events
when no specific variation requested:
# Never
# Binary Input Change With Time
# Binary Input Change With Relative Time
# Configurable (attach explanation)
Sends Static Data in Unsolicited Responses:
# Never
# When Device Restarts
# When Status Flags Change
No other options are permitted.
# ENABLE/DISABLE UNSOLICITED
Function codes supported
Default Counter Object/Variation:
# No Counters Reported
# Configurable (attach explanation)
# Default Object ______________
Default Variation
______________
# Point-by-point list attached
Counters Roll Over at:
# No Counters Reported
# Configurable (attach explanation)
# 16 Bits
# 32 Bits
# Other Value _____________
# Point-by-point list attached
Sends Multi-Fragment Responses: # Yes # No
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7
GLOSSARY OF TERMS
application
Binary
A piece of software (a program) consisting
of one or more processes and supporting
functions.
A number system having only two symbols (1 and
0), and where values are expressed in the
base two number system.
Bit
Abbreviation of binary digit. The smallest
unit of information in a binary system. Has
a value of either one (1) or zero (0).
Master
The client or host station or computer,
with which the RTU equipment
communicates. Also referred to as a host
or host computer.
Non-volatile
random-access memory
A semi-permanent type of data storage
(memory) that is backed up by batteries to
maintain stored data even if system power
is lost. Can be both read and changed by
the system. Abbreviated as NVRAM.
Random-access memory
A type of temporary data storage
(memory) that can be read and changed
while the computer is in use. Data stored
in random-access memory is lost if the
system loses power. Abbreviated as RAM.
Remote terminal unit
8
A piece of equipment located at a
distance from a master station to
monitor and control the status of
outlying equipment, and to
communicate the information back to
the master station or host. Abbreviated
as RTU.
DNP Users Group
P009-0IG.SUB, Version 2.00
Sequence of events
DNP V3.00 Subset Definitions
P009-0IG.SUB, Version 2.00
A time-tagged change of state, logged
as part of a chronological record of
significant changes in the condition of
a particular point or points being
monitored. Abbreviated as SOE.
9
LIST OF ACRONYMS
AND ABBREVIATIONS
DNP
distributed network protocol
IED
intelligent electronic device
NVRAM
non-volatile random-access memory
OSI
open systems interconnect
RAM
random-access memory
RTU
remote terminal unit
SOE
sequence of events
10
DNP Users Group
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Distributed Network Protocol (DNP) V3.00
Transporting DNP V3.00 over Local and Wide Area
Networks
Version 1.0
December 15, 1998
Prepared by:
Michael Thesing
Advanced Control Systems, Inc.
Norcross, GA USA
Acknowledgements:
The author wishes to thank Parker McCauley and Ken Murphy for their advice, expertise, and review of this
document.
Other contributors:
John Phillips
Foxboro Australia Pty Limited
Grant Gilchrist
GE/Harris Energy Control Systems
DNP is a trademark of the DNP Users Group.
Transporting DNP over LAN/WAN
December 15, 1998
Copyright © 1998 DNP Users Group. All rights reserved.
ii
Transporting DNP over LAN/WAN
December 15, 1998
Contents
1
2
3
4
5
6
7
8
Overview...............................................................................................................................................................1
1.1
Purpose ..........................................................................................................................................................1
1.2
Notes..............................................................................................................................................................1
1.3
Protocol Stack................................................................................................................................................1
1.4
Conclusions ...................................................................................................................................................2
Physical, Link, and Network layers ...................................................................................................................3
2.1
Physical and Link layers................................................................................................................................3
2.2
Network layer ................................................................................................................................................3
Transport layer ....................................................................................................................................................3
3.1
Protocol characteristics..................................................................................................................................3
3.1.1
UDP .......................................................................................................................................................3
3.1.2
TCP........................................................................................................................................................3
3.2
Network Topologies ......................................................................................................................................3
3.2.1
Network A .............................................................................................................................................4
3.2.2
Network B..............................................................................................................................................6
3.2.3
Network C..............................................................................................................................................8
3.3
Summary........................................................................................................................................................9
DNP Layers ........................................................................................................................................................10
4.1
Confirmations ..............................................................................................................................................10
4.2
Keep-alive timer ..........................................................................................................................................10
4.3
Multiple frames in UDP...............................................................................................................................11
4.4
Broadcast Address .......................................................................................................................................11
Security...............................................................................................................................................................11
Time Sync ...........................................................................................................................................................11
6.1
Desired Behavior .........................................................................................................................................12
6.2
Procedure.....................................................................................................................................................12
6.3
Driver requirement ......................................................................................................................................13
Socket requirements ..........................................................................................................................................13
7.1
Background..................................................................................................................................................13
7.2
TCP/UDP Port Number for DNP ................................................................................................................14
7.3
Making TCP connections ............................................................................................................................14
7.4
Broken connections .....................................................................................................................................16
7.5
Typical architecture .....................................................................................................................................16
References ..........................................................................................................................................................18
ANNEX A (informative) TCP vs. UDP in a Wide Area Network .........................................................................19
ANNEX B (normative) Additions to Existing documents......................................................................................21
New Function Code (24) .........................................................................................................................................21
B.1.1 Changes to Table 3-1 in the Application Layer document.........................................................................21
B.1.2 Addition to Chapter 4 in the Application Layer document........................................................................21
New Object (Obj 50, Var 03) ..................................................................................................................................21
B.2.1 Addition to Data Object Library document ...............................................................................................21
iii
Transporting DNP over LAN/WAN
December 15, 1998
1 Overview
1.1 Purpose
DNP V3.00 (hereafter referred to simply as DNP) was designed for serial point-to-point communication (e.g. RS232) with limited support for half duplex serial networks (e.g. RS-485). In order for devices to exchange DNP
messages in a local (LAN) and/or wide area network (WAN), one must either augment the protocol to support a
network environment or use an existing network transport mechanism. This document takes the latter approach;
specifically, to define how to transport DNP traffic on the internet protocol suite.
1.2 Notes
The internet protocol suite is sometimes referred to as the TCP/IP protocol. For this document, the internet protocol
suite is defined to include both transport layers, TCP and UDP, as well as the IP network layer. The individual
layers are summarized in sections 2 and 3.
Throughout this document the term “device” as it applies to a DNP device may be interpreted to be either a physical
unit (i.e. a standalone product, RTU, IED, etc.) or a logical entity within a physical unit (i.e. logical RTU, virtual
IED, etc.).
1.3 Protocol Stack
The most attractive reasons for choosing the internet protocol suite as a transport mechanism for DNP are:
• Seamless integration of the substation LAN to the corporate WAN of the utility
• Leverage existing equipment and standards
The internet protocol suite is designed to be platform independent and is supported on virtually every computer
system in the world. It is highly scalable (LAN to WAN) and many quality implementations exist for both
embedded and workstation operating systems. The recent growth of the Internet has fueled the large availability of
equipment and has proved that the internet protocol suite is capable of transporting tremendous quantities and types
of data.
The internet protocol suite and DNP use the OSI layering paradigm; each piece of the protocol stack in one station
logically communicates with the corresponding piece in the other station(s). It is therefore easy to build DNP "on
top of" the internet protocol suite since the internet layers appear transparent to the DNP layers (see Figure 1-1).
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Logical Communications
Station 1
Station 2
DNP Application
APDU
APDU
DNP Transport
TPDU
TPDU
DNP Link Protocol
LPDU
LPDU
TCP,UDP
Transport
Transport
IP
Network
Network
Link
Link
device driver/link
DNP Protocol
TCP/IP Protocol
Suite
Figure 1-1 Protocol Stack.
1.4 Conclusions
All DNP devices, be they physical or logical, that are to communicate in the DNP V3.00 Protocol over a
LAN/WAN shall be subject to the following basic requirements:
•
•
•
•
•
•
•
•
DNP shall use the internet protocol suite to transport messages over the LAN/WAN. The recommended
physical/link layer is Ethernet, but the internet protocol suite has been implemented over a wide variety of
networks.
All devices shall support connection-oriented (TCP) and connection-less sockets (UDP). TCP is required for
wide-area networks and is strongly recommended for local-area networks. UDP is appropriate for non-critical
messages such as data monitoring or configuration. UDP may be used on high-reliability single-segment LANs
and must be used if broadcast delivery is required.
The DNP Enhanced Protocol Architecture (EPA) of DNP shall be retained so that the protocol requirements
contained in each layer do not need to be reinvented.
Link Layer confirmations shall be disabled. Application Layer confirmations shall be used per the subset
definitions and technical bulletin [Ref. 13].
A mechanism for verifying the on-line status of an Outstation must be implemented. A periodic keep-alive
message is recommended.
All devices should be configured with the IP address of the communicating host. This address must be set in a
secure manner and verified at the server-end before a connection is made.
The method for time synchronization on a LAN is defined; the WAN case is not addressed in this document.
General recommendations for making socket connections between devices are outlined. Data providers such as
IEDs, Meters, and devices that are "downstream" in the SCADA system shall be the server-end of the
connection. Data users such as RTUs, Master Stations, and devices that require access to the data shall be the
client-end of the connection.
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2 Physical, Link, and Network layers
2.1 Physical and Link layers
Although there is nothing in the internet protocol suite that precludes operation on other types of networks; e.g.
ARCnet, Token-Ring, AppleTalk, etc., Ethernet/IEEE 802.3 is clearly the dominant computer network technology.
This document recommends using Ethernet for the Link and Physical layers because of this ubiquity, but also
because Ethernet provides the necessary bandwidth and physical media for substation and control center LANs. 10
and 100 Mbit/second is supported for twisted-pair copper, coaxial cable, and fiber optic cable with existing work to
standardize 1000 Mbit/second networks ongoing. The installation of Ethernet wiring and equipment is well
understood and standardized.
2.2 Network layer
Internet Protocol (IP) forms the basis for the internet Protocol suite and therefore is the recommended Network
layer protocol. IP provides a connectionless, best effort datagram delivery service to the transport layer protocols.
Connectionless means that IP does not maintain any state information about the link so each datagram is routed
independently of all others. Best effort delivery means that the protocol has mechanisms for routing the datagram
and simple error reporting, but that delivery is not guaranteed. Reliability is left up to the transport layer protocol.
3 Transport layer
The Transport layer of the internet protocol suite consists of two distinct services, User Datagram Protocol (UDP)
and Transmission Control Protocol (TCP). TCP shall be the primary transport service for DNP messages because of
its reliably; UDP can be used on a high-reliability single-segment LAN and in specific cases where small pieces of
non-critical data need to be sent or when broadcasting is required. UDP can also be used in specific cases as listed
in table 3-1. Annex A describes why UDP cannot be used if the DNP messages must be routed over the utility
enterprise or wide area network.
3.1 Protocol characteristics
3.1.1
UDP
UDP provides a connectionless service for sending datagrams between hosts. Sending one UDP datagram causes
exactly one IP datagram to be sent. All that it adds beyond IP is the ability to exchange datagrams between multiple
processes on a host and rudimentary error detection. UDP supports all the addressing modes of IP – unicast,
multicast, and broadcast.
3.1.2
TCP
TCP provides a connection-oriented service for sending a stream of bytes between hosts. The protocol determines
how to break the stream into IP datagrams based on the characteristics of the network. TCP insures that the same
stream of bytes sent to the transmitting side of the connection will be available on the receive side. It accomplishes
this using acknowledgements, sequencing of the data, and dynamic timer mechanisms. Lost or corrupted packets are
retransmitted transparently to the higher layers. The only addressing mode supported by TCP is unicast. Multicast
and broadcast are not applicable in a connection-oriented protocol.
3.2 Network Topologies
Following are the 3 possible network topologies in terms of IP routability from the perspective of a substation or
remote LAN. Each topology diagram uses typical equipment on the various networks to illustrate basic
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Transporting DNP over LAN/WAN
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functionality. Clearly, many other types of devices can exist on enterprise wide area networks as well as on the
substation LANs.
3.2.1
Network A
Control
Center LAN
Master station
Master station
Server
Serial Link:
Dedicated
Radio
Dial-up
etc.
RTU/Data
Concentrator
Substation
LAN
Ethernet
Relays
Meters
Other
IEDs
Figure 3-1 Network Topology A
This is the most basic implementation of a substation LAN in that it doesn't provide for the ability to access
substation components outside of the LAN. It does provide for IED-to-IED communication in addition to the
normal RTU-to-IED communication. Figure 3-2 shows a typical data transfer path from an IED.
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Transporting DNP over LAN/WAN
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Control
Center LAN
Master station
Master station
Master station
Server
Server
Serial Link:
Dedicated
Radio
Dial-up
etc.
RTU/Data
Concentrator
Substation
LAN
Ethernet
Relays
Meters
Other
IEDs
Figure 3-2 Network A IED Communication
DNP traffic could be transported in a couple of ways in this topology. The first method is to use TCP to establish a
connection between the RTU/Data Concentrator (RTU/DC) and each IED. IEDs may also establish connections to
share data. TCP provides a reliable connection between all devices.
The second method is to use UDP to transport all DNP frames since the messages do not need to be routed and,
assuming a fairly high reliability LAN construction, the packet loss would be very low. DNP link layer
confirmations shall be disabled. Application layer confirmations shall be used as recommended in the technical
bulletin [Ref. 13]. If broadcast messages are required, UDP must be used since TCP is strictly a point-to-point
protocol. Unsolicited responses are recommended for both TCP and UDP to improve efficiency.
An alternate method, mentioned here because of its simplistic client implementation, would be to use UDP to
broadcast all DNP Link Layer frames to the network and let each device determine its messages based on the DNP
destination address. This method is equivalent in functionality to a RS-485 network with the addition of defined
media access and higher baud rate. The advantage of this method is that it is very easy to implement in code and
has the lowest possible RAM requirements. The disadvantages are:
• An IED designed exclusively for this network cannot be used in networks requiring that the IP datagrams be
routed.
• Since all the frames would have the destination address set to the subnet broadcast address, all hosts would
have to process all messages up through the transport layer and all DNP hosts would have to process the
message through the DNP Link layer. This is a tremendously inefficient use of the network bandwidth and
processing on all network hosts.
For these reasons, this method must not be used.
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3.2.2
Network B
To other parts of
enterprise network
Enterprise
WAN
Gateways
PCs/Workstations
Control
Center LAN
Router
Master stations
Servers
PPP
Remote workstation
Fiber
PPP
Digital
etc.
Substation
LAN
Router
RTU/Data
Concentrator
Ethernet
Relays
Other
IEDs
Meters
Figure 3-3 Network Topology B
This implementation of a substation LAN provides access to substation components through the utility enterprise.
Figure 3-3 represents a typical example given by most substation LAN standards currently under development. IEDto-IED, RTU-to-IED, and enterprise-to-IED communications are supported. Figure 3-4 shows a typical data transfer
path from an IED.
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To other parts of
enterprise network
Enterprise
WAN
Gateways
PCs/Workstations
Control
Center LAN
Router
Master stations
Servers
PPP
Remote workstation
Fiber
PPP
Digital
etc.
Substation
LAN
Router
RTU/Data
Concentrator
Ethernet
Relays
Other
IEDs
Meters
Figure 3-4 Network B IED Communication
All devices on the substation LAN must support TCP connections since the IP datagrams are routed (see Annex A).
UDP can be used for non-critical data such as Virtual Terminal objects or device monitoring outside of the normal
SCADA command and control loops. As in topology A, UDP provides the ability to broadcast frames so that a
device can share data with other LAN devices efficiently.
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3.2.3
Network C
To other parts of
enterprise network
Enterprise
WAN
Gateways
PCs/Workstations
Control
Center LAN
Master stations
Router
Servers
PPP
Data
Acquisition
Unit
Remote workstation
Router
Serial Link:
Dedicated
Radio
Dial-up
etc.
Router
Remote
LAN
Ethernet
Relays
Other
IEDs
Meters
Figure 3-5 Network Topology C
This implementation of a remote LAN provides access to devices only through a routed communication link. For
example, imagine a remote station requiring periodic monitoring but not full RTU functionality. The Data
Acquisition Unit (DAU) could potentially handle multiple remote stations. The Master Stations would then access
the remote data via the DAU. Figure 3-6 shows a typical data transfer path from an IED.
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To other parts of
enterprise network
Enterprise
WAN
Gateways
PCs/Workstations
Control
Center LAN
Router
Master stations
Servers
PPP
Data
Acquisition
Unit
Remote workstation
Router
Serial Link:
Dedicated
Radio
Dial-up
etc.
Router
Remote
LAN
Ethernet
Relays
Other
IEDs
Meters
Figure 3-6 Network C IED Communication
All devices in this topology must support TCP. UDP cannot be used between an IED and the Data Acquisition Unit
and only makes sense if an IED wishes to communicate with another IED on the remote LAN.
3.3 Summary
All devices shall support both TCP because of its reliable delivery characteristic over all network topologies and
UDP because of the potential uses of broadcasting, its efficiency when small pieces of non-critical data need to be
transported, and when operating over a high reliability, single segment LAN. For example, UDP would be
appropriate when many computational nodes require a common IED value but the stability of the system is not
compromised if a few values are lost. Table 3-1 shows which transport layer to use in the various cases.
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Protocol
Use in the case…
TCP
• Most situations
requiring point to point
communications
• Mesh topology WAN
UDP
• Broadcast on a LAN
• Equivalent to TCP on high-reliability
single-segment LAN
• More economical for pay-per-byte, nonmesh WAN, e.g. Cellular Digital Packet
Data (CDPD).
• Low priority data, e.g. data monitor or
configuration
Table 3-1 Appropriate use of transport layer
4 DNP Layers
The three protocol layers of DNP are integrated together to form what the Basic 4 documents call the Enhanced
Performance Architecture (EPA). Essentially, the functionality called out in the OSI 7-Layer model is either not
needed in DNP or has been combined to simplify the design of DNP compatible devices. The three layers of DNP
work together and cannot be separated without adding capabilities to a layer that are already contained within
another layer.
For example, one might consider extracting the DNP Application layer and transporting it directly over the internet
protocol suite. But, the Application layer doesn't have any addressing mechanism; this is contained in the Link
Frame. Using only the IP addresses precludes having more than one DNP entity (i.e. virtual RTUs) per IP address.
TCP doesn't have error detection that is adequate for the critical nature of SCADA data; this is also in the Link
Frame. The Application Layer has no means for determining the start of a new message in the serial stream; the
start characters and length field in the Link Frame provides this. Therefore, since the protocol requirements of DNP
are present in all three layers, there is no need to break them apart.
This architecture provides an additional benefit for vendors in that they can share most of the DNP code with
existing serial channel implementations. The only difference comes in the interface to the internet protocol suite
which is very similar to a serial port in that TCP also provides a stream of data with no packet or frame
demarcations.
4.1 Confirmations
Link layer confirmation shall be explicitly disabled when communicating via the internet protocols. TCP has its
own very robust mechanisms for insuring data delivery. UDP does not have such a mechanism, but its uses are
limited to cases where the reliability of the communications medium is very high or the transported data is not
critical.
Application layer confirmations may still be used in accordance with subset and technical bulletin recommendations
[Ref. 13].
4.2 Keep-alive timer
If the server-side of a TCP connection goes down and comes back up, the client-side has no way of knowing until it
sends a message to the server and receives the RST flag in the TCP header. If an outstation is operating in an
unsolicited mode, this could be minutes depending on the scheduling of integrity polls. Therefore, it is necessary to
add some type of keep-alive timer to allow clients to periodically determine the on-line status of servers or peers.
Note: If the client-side of a TCP connection goes down, it will presumably try to reconnect when it comes back up.
The server will process this request, close the existing connection, and reconnect.
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TCP offers such a timer, but a typical implementation is 2 hours, which is not sufficient for the critical nature of the
data carried by DNP. Note: some internet protocol implementations allow this timeout to be changed, but this
capability is not universal.
The recommended message to use for such a timer is the Link Layer Request Status message (0xC9). It is very low
overhead for the devices and is already supported at all subset levels. A suitable time would be once every 10
seconds (although it should be configurable) after there has been no other activity from that device. To facilitate
interoperability, the keep-alive timer shall be supported by all devices. However, it must be possible to disable via
configuration for cases where the normal application layer traffic (e.g. polling) provides on-line status detection.
4.3 Multiple frames in UDP
If UDP is used in one of the cases specified in section 3.3, a receiver must be capable of parsing multiple DNP Link
Layer frames from a UDP fragment.
4.4 Broadcast Address
If UDP is used to broadcast a datagram to multiple devices on a LAN, the DNP address must be set to 0xFFFF and
all logical DNP devices at all IP addresses within the domain of the broadcast must receive the encapsulated DNP
frame.
5 Security
In a point-to-point serial channel, DNP devices are protected from inadvertent or hostile access by the physical
nature of the connection. If DNP is going to be transported over an enterprise wide network, a method for
controlling access needs to be defined by the vendor of each device. Each device needs to be configured such that
only the intended connections are made. This requires setting the IP address of the server host at the client side and
setting the IP address of the client host (or list of clients) at the server side. Servers then must use the IP address to
validate client requests and make the appropriate logical port connections. This feature shall be supported by all
devices, however it must be possible to disable via configuration.
A server may wish to enable only one connected client at a time or provide for a failover capability, e.g. if a client
fails then another client can connect with the server and continue the service that was provided by the failed client.
[Ref. 12]
The valid host IP addresses can only be set in a secure manner. Some possibilities for doing this include, but are not
limited to:
• A local interface using a proprietary program.
• A simple HTTP server with password accesses to the configuration information. Using HTTP in this manner
avoids having to invent new DNP objects to carry both the configuration info and the security info.
• A terminal-like interface using Virtual Terminal objects over UDP (see Technical Bulletin 9804-004).
Each equipment vendor will have to determine an appropriate method.
6 Time Sync
All time synchronization shall be done at the local network only. It is not practical to do time sync over IP routers
as their delays are typically not consistent and vary based on network loads. The Network Time Protocol (NTP) is
too large and requires too many resources to be appropriate for DNP. The source of the time at the local network
shall be chosen as required by the system.
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The time synchronization method defined in Chapter 6 of the Application Layer document is not appropriate for a
high-speed (relative to RS-232) LAN because:
• The propagation delay measurement is negligible [Ref. 2].
• The internet protocol stack causes a variable delay between DNP and the network.
• Recording the time at the first bit of the first byte does not account for network collisions.
In the following procedure, the Master station is defined as the host on the LAN with the accurate time source. See
Annex B for a complete description of the new function code and object.
6.1 Desired Behavior
Since the propagation delay on an Ethernet LAN is very small, the offset time between the Master Station and the
Outstation can be measured directly. The following procedure outlines a method for both hosts to record their time
at the same instant, namely, when the last character of a message is transmitted from Master Station and received at
the Outstation. The difference in these times represents the offset between the two hosts and can be used as a
correction factor in the Outstations.
6.2 Procedure
1.
2.
3.
The Master station sends a Record Current Time (FC 24) request to the outstation. The Master records the
time of transmission of the last octet sent to the network (denote this as MS_Time).
The Outstation receives the message and records the time of reception of the last octet (denote this as
OS_Time). It returns a Null Response.
The Master Station issues a Write request with a Time And Date at Last Recorded Time object (obj 50, var
3) containing the value MS_Time. The Outstation calculates the offset (MS_Time – OS_Time). The
Outstation can set its clock accordingly or apply the offset when event times are reported.
This procedure can also use broadcast messages to synchronize multiple Outstations simultaneously since the
Record Current Time request is received at all hosts on the LAN at the same instant. The Master would utilize
UDP to send the broadcast datagram, and all Outstations that need synchronization must be capable of accepting
this datagram.
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Master Station
Outstation
Time
LAN Media
MS_Time_DNP
OS_Time
DNP
Null Response
OS_Time_DNP
internet stack
Record Current
Time (FC 24)
Ethernet driver and hardware
Ethernet driver and hardware
internet stack
DNP
MS_Time
Time & Date at
Last Recorded Time
(Obj 50, Var 03)
Calculate offset
offset = value in Time & Date Obj minus time when Record Current
Time Obj received
Desired case
offset = MS_Time - OS_Time
Figure 6-1 Time line for synchronization
6.3 Driver requirement
As in the serial channel time synchronization, the procedure is handled with application layer messages. However,
this procedure requires that the Ethernet driver provide the ability to record the last octet time on transmission and
receive. The time sync process is greatly influenced (and varied) by processor speed, interrupt latencies, internet
protocol stack design, etc. Time resolution to the millisecond level cannot be accomplished without this capability.
If a device (Master or Outstation) cannot record time at the Ethernet driver, it should do so as close as possible to
the internet stack interface (shown in Figure 6-1 as MS_Time_DNP and OS_Time_DNP). As noted, this introduces
an error factor in the synchronization process. A device may wish to minimize this error by adding (at the Master
end) or subtracting (at the Outstation end) a predetermined value that reflects an average delay through the internet
stack and Ethernet driver. This "fudge factor" does not take into account the delay caused by Ethernet collisions
and retransmission. However, it may reduce the average error to a level that can be tolerated in the system.
7 Socket requirements
The following discussion assumes the use of some variation of the sockets API, either Berkeley or Winsock derived,
in order to implement DNP over the internet protocol suite. For information on the sockets API, see [Ref. 5].
7.1 Background
TCP client The side of the link that calls the connect() function to initiate the connection on a socket.
TCP server The side of the link that calls the listen() function to wait for a connection request on a socket.
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Transporting DNP over LAN/WAN
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For a TCP connection to take place, one side must be the server and one side must be the client. The client requests
a connection by specifying the IP address and port number of the server. Once the connection is made, data is
transferred without either side having to specify the IP address and port number. For UDP (connection-less)
communications, each side includes the address and port number with each transmission. Each host that receives a
UDP datagram is then provided with the sending host address.
7.2 TCP/UDP Port Number for DNP
All devices shall support TCP and UDP communications on port number 20000. This number has been registered
with the IANA (Internet Assigned Numbers Authority) for use with DNP. All connection requests and all UDP data
are sent to this common port number.
7.3 Making TCP connections
Making a TCP connection between two devices can be viewed conceptually as replacing the traditional serial port
communication link with a sockets interface over the network. For example, figure 7-1 shows the typical
communication links between two Master Stations and an IED.
RTU/IED
Logical
RTU(s)
Logical
RTU(s)
Master Station A
DNP
Communication
Object
DNP
Communication
Object
DNP
Communication
Object
Serial Port Driver
Serial Port Driver
Serial Port Driver
RS232
RS232
RS232
Dedicated line
Radio
Dial-up
etc.
Master Station B
DNP
Communication
Object
Serial Port Driver
RS232
Dedicated line
Radio
Dial-up
etc.
Figure 7-1 Serial port communications
Now, replace the serial communication with an Ethernet network, internet protocol stack, and sockets interface.
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Transporting DNP over LAN/WAN
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RTU/IED
Logical
RTU(s)
Master Station A
Logical
RTU(s)
DNP
Communication
Object
DNP
Communication
Object
Socket A
Socket B
DNP
Communication
Object
IP/Ethernet driver
Socket A
IP/Ethernet driver
Ethernet
Ethernet
Master Station B
Hub
DNP
Communication
Object
Socket B
IP/Ethernet driver
Ethernet
Figure 7-2 Network communications
All of the DNP components stay the same; the only part that changes is the lowest level communications drivers. In
fact, since TCP accepts a stream of data just like a serial port, the interface between the DNP Communication
Object and the lower level driver can also remain virtually the same.
For a network in which all devices are continually present and available, it is recommended that:
If the device is a data provider (e.g. IED, meter, RTU, etc.), it should be the server end of the connectionoriented (TCP) socket. It may be capable of supporting multiple logical ports on a device.
Each data user (e.g. Master Station, RTU/Data Concentrator, peer IED, etc.) should initiate the connection as
the client end of the connection-oriented (TCP) socket.
For a network in which some devices need to establish a communication link before joining the network (e.g.
SLIP/PPP dial-up):
The data provider may initiate the connection as the client and the data user will have the listening socket.
Requirements
Data providers shall, at minimum, support the server end of a TCP connection (i.e. be capable of accepting
connection requests on a listening socket). If a data provider has the capability to join a network but not be
continuously accessible (e.g. dial-up), it shall support the client end of a TCP connection (i.e. be capable of
initiating connection requests). Data users shall be configurable to support both ends (client and server) of the
socket connection to insure universal support for all data providers and all system architectures. All devices shall
be capable of simultaneously accepting messages via the connectionless (UDP) port and the connection oriented
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Transporting DNP over LAN/WAN
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(TCP) port. If there are multiple DNP logical entities within the device, the messages must be routed to the correct
entity (e.g. virtual device, logical RTU, etc.).
7.4 Broken connections
If a DNP/TCP connection is made and one of the devices losses power or inadvertently resets, there must be
mechanisms to inform the other device so that the connection can be reestablished.
If the server-side goes down:
When the next message is sent (see section 4.2 regarding DNP keep-alive messages), the server will send a TCP
packet with the RST flag set. This will cause subsequent calls to recv() or select() to return an error if the
socket is non-blocking or the send() call will fail if the socket is blocking. The client must close the current
connection and reconnect.
If the client-side goes down:
When the client-side restarts and attempts a new connection, the server will process this request, close the existing
connection, and reconnect.
7.5 Typical architecture
Figure 7-3 illustrates the architecture of a device that supports TCP client, TCP server, and UDP connections. Two
TCP server connections are shown to illustrate how connection requests are controlled by the TCP Manager object.
It is recommended that each DNP Port be configured with the peer IP address. This allows for each connection
request to be validated in a secure manner (by the TCP Manager in this example) and each UDP datagram to be
routed to the correct DNP Port. If a device supports multiple logical entities (i.e. logical RTUs), it must be able to
configure these entities to use a single DNP Port.
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sockets API
TCP Manager
- TCP Listening socket
- validate connections
Internet Protocol
Physical and
Link Layers
Ethernet
Connection requests
TCP Data
Server-side
socket driver
DNP
communication
object
Logical
RTU(s)
TCP Data
Server-side
socket driver
DNP
communication
object
Logical
RTU(s)
Client-side socket
driver
DNP
communication
object
Logical
RTU(s)
DNP
communication
object
Logical
RTU(s)
Connection request
TCP Data
UDP Only driver
UDP Router
- to all ports
UDP Datagrams
Figure 7-3 Example sockets architecture
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Transporting DNP over LAN/WAN
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8 References
[1] DNP V3.00, Basic 4 Document Set
[2] Gilchrist, Grant. "Proposal for Use of Distributed Network Protocol in Substation LANs." Harris Distributed
Automation Products, version 0.2. Dec. 11, 1996.
[3] Falk, Herbert. "Comments on 'Proposal for Use of Distributed Network Protocol in Substation LANs'."
SISCO. Jan. 14, 1997.
[4] Stevens, W. Richard. TCP/IP Illustrated, Volume 1: The Protocols. Addison Wesley Longman, Reading, MA.
1994.
[5] Stevens, W. Richard. UNIX Network Programming, Volume 1, 2nd Edition. Prentice Hall, Upper Saddle River,
NJ. 1998.
[6] Miklovic, Daniel T. Real-time Control Networks. Instrumentation Society of America, Research Triangle
Park, NC. 1993.
[7] Postel, J., Ed. "Internet Protocol." SRI International, Menlo Park, CA, Sept. 1981. RFC-791.
[8] Postel, J., Ed. "Transmission Control Protocol Specification." SRI International, Menlo Park, CA, Sept. 1981.
RFC-793.
[9] Postel, J., Ed. "User Datagram Protocol." USC/Information Sciences Institute, September 1981. RFC-768.
[10] Mogul, J. and Deering, S., "Path MTU Discovery." Nov. 1990. RFC-1191.
[11] Kent, C.A., and Mogul, J.C., "Fragmentation Considered Harmful." Computer Communications Review, vol.
17, No. 5, pp.390-401. Aug. 1987.
[12] Phillips, John. "Transporting DNP 3.0 over Local and Wide Area Networks." Foxboro Australia Pty Limited,
version 0.1, September 23, 1998.
[13] DNP V3.00 Technical Bulletin 9804-002. DNP Confirmation and Retry Guidelines.
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ANNEX A (informative) TCP vs. UDP in a Wide Area Network
It has been proposed that User Datagram Protocol (UDP) be used for transporting DNP in a network. The only
features that UDP adds to the underlying IP protocol is port addressing and a 16-bit checksum. All of the other
requirements for transporting the sensitive, time critical SCADA information would have to be handled by DNP.
DNP includes a number of transport layer capabilities. But since DNP was designed for RS-232 and RS-485 type
serial communications, it does not contain all of the necessary mechanisms for an enterprise wide internet. For
example:
•
Reordering of packets received out of order and detecting duplicate packets – the DNP transport layer only has
a 6-bit sequence number. In a large internet, packets can arrive out of order since each packet is routed
independently and may traverse totally different paths (different speeds). 64 sequence numbers is not enough
if, for example, an internet contains a combination of slow serial links (PPP or SLIP connections) and LFNs
(Long Fat Networks = networks with high bandwidth-delay products). [Ref. 3].
•
Timeout and retransmission – Clearly, the requirements for a local serial network versus an internet are
different. In a local network, the route and round-trip time (RTT) for IP packets remains relatively constant. On
an internet, the RTT can change from packet to packet due to such factors as increased congestion on individual
routes, equipment failures, etc. Timeouts must be adaptive to account for these cases.
•
Fragmentation – IP has no timeout or retransmit capabilities as well as no capabilities for transmitting
individual fragments. So, if the datagram is fragmented in IP and one of the fragments is lost, the entire
datagram (1 or more DNP Link Layer frames) must be retransmitted. DNP can handle this by either confirming
all Link Layer packets or by throwing away the entire Application Layer fragment and letting the sending
station timeout and retransmit. Both cases have real performance issues [Ref. 2].
The maximum size of a datagram using the DNP Link Layer on UDP/IP is 320 octets (maximum DNP link
frame size (292 octets) + 28 octets for the UDP/IP headers). For most networks, the minimum datagram size is
576 octets with two notable exceptions. First, the IP specification states that the minimum datagram size that a
module must handle is 68 octets (RFC-791 IP). Modules that have this limitation are rare. Second, if the Pointto-Point Protocol (PPP) is employed in the network, the MTU (Maximum Transmission Unit)decreases to 296
octets for a low delay link (RFC-1191). Clearly, the frame "packing" proposed in [Ref. 2] will exasperate the
problem. See Ref. 11 for further arguments as to why fragmentation should be avoided.
Transmission Control Protocol (TCP) is a much better choice for transporting DNP data over a WAN. TCP insures
that the same stream of bytes sent to the transmitting side of the connection will be available on the receive side. It
accomplishes this using acknowledgements, sequencing of the data, and dynamic timer mechanisms. Lost or
corrupted packets are retransmitted transparently to the higher layers. TCP addresses the above internet deficiencies
of DNP in the following manner:
•
TCP uses a 32-bit sequence number and a 32-bit acknowledge number to insure that data is received in order.
•
TCP manages 4 timers for each connection – a retransmission timer for expected acknowledgements, a persist
timer to keep window size information flowing, a keepalive timer for detecting if one end of the connection
goes down without warning, and a maximum segment lifetime timer for completing a disconnection operation.
TCP adapts its retransmission timer to the conditions of the connection.
•
TCP tries to avoid fragmentation by allowing both sides of a connection to optionally specify the maximum
segment size (MSS). If the destination IP address is "nonlocal", the MSS normally defaults to 536.[Ref. 4 p.
237] Furthermore, RFC1191 outlines a way for hosts to determine the path MTU for paths that may include
lower MTU connections. Since fragmentation is handled by TCP, DNP Link Layer confirms are not needed
and performance is only limited by the characteristics of the connection, not by DNP.
19
Transporting DNP over LAN/WAN
December 15, 1998
In addition, TCP includes such features as packet reduction using the Nagle algorithm, sliding data windows to
allow multiple packets before acknowledgements, congestion avoidance for links with slow segments, and
repacketization to increase performance. Obviously, all of these features come at a price, albeit a fairly reasonable
one. For one popular embedded implementation, the ROM requirement for the full internet protocol stack is 115K;
RAM is 25K + 4K/socket. Considering that most devices on a DNP network will have to maintain only 1
connection to a data concentrator of some sort, this is very small. At 4K/socket, this is reasonable and scalable. If
devices wish to establish IED-to-IED communications (i.e. to share data points), the number of sockets is still low
since this would typically be required in only a few devices on the network.
20
Transporting DNP over LAN/WAN
December 15, 1998
ANNEX B (normative) Additions to Existing documents
New Function Code (24)
B.1.1 Changes to Table 3-1 in the Application Layer document
Time Synchronization Function Codes
23
Delay Measurement
…
24
Record Current Time
Used in a network application to allow the
Master Station and the Outstation to record
their time at the same instant.
Reserved
25-120
Reserved for future use
B.1.2 Addition to Chapter 4 in the Application Layer document
4.25 RECORD CURRENT TIME (FUNCTION CODE 24)
This function is used to in a network application to allow the Master Station and the Outstation to record their time
at the same instant. It is the first step in the network time synchronization process.
Time is recorded by the Master Station when the last character of a message is transmitted. Time is recorded at the
Outstation when the last character of the message is received. The difference in these times represents the offset
between the two hosts and can be used as a correction factor in the Outstation.
AC
FC = 24
Figure 4-45 Master Request to Record Current Time
The Outstation responds with a Null Response
New Object (Obj 50, Var 03)
B.2.1 Addition to Data Object Library document
TIME AND DATE AT LAST RECORDED TIME
Data Object 50 - Variation: 03
Description:
The time and date at last recorded time object is an information object that represents the absolute time of day and
date when the last Record Current Time function code was send. This object should be used for timesynchronization in networked applications.
21
Transporting DNP over LAN/WAN
December 15, 1998
Object Coding:
Absolute Time
Absolute Time
=
7
6
5
4
3
2
1
0
15
14
13
12
11
10
9
8
23
22
21
20
19
18
17
16
31
30
29
28
27
26
25
24
39
38
37
36
35
34
33
32
47
46
45
44
43
42
41
40
UI48 [0..47] <0..248-1, msec>
Narrative:
Absolute Time is recorded as milliseconds since midnight, January 1st, 1970, at zero hours, zero minutes, zero
seconds, and milliseconds.
22
DNP3 TRANSPORT FUNCTIONS
Version 0.02
01-August-2000
DISCLAIMER STATEMENT
DNP User Group documents and publications are not consensus documents. Information contained in this and
other works has been obtained from sources believed to be reliable, and reviewed by credible members of the
DNP User Group and/or the DNP User Group Technical Committee. Neither the DNP Users Group nor any
authors/developers of DNP documentation guarantee, and each such person expressly disclaims responsibility
for ensuring, the accuracy or completeness of any information published herein, and neither the DNP Users
Group nor its authors/developers shall be responsible for any errors, omissions, or damages arising out of use of
this document.
Likewise, while the author/developer and publisher believe that the information and guidance given in this work
serves as an enhancement to users, all parties must rely upon their own skill and judgment when making use of
it. Neither the author nor the publisher assumes any liability to anyone for any loss or damage caused by any
error or omission in the work, whether such error or omission is the result of negligence or any other cause. Any
and all such liability is disclaimed.
This statement was developed by the DNP User Group Technical Committee and represents the considered
judgment of a group of software developers with expertise in the subject field. The DNP User Group is a global
forum for users and implementers of the protocol and promotes implementers and developer information and
interaction exchange. This work is published with the understanding that the DNP User Group and its
authors/developers are supplying information through this publication, not attempting to render engineering or
other professional services. If such services are required, the assistance of an appropriate professional should be
sought. The DNP User Group is not responsible for any statements and/or opinions advanced in this publication.
NOTICE OF RIGHTS - DNP USERS GROUP
The contents of this manual are the property of the DNP Users Group. Revisions or additions to the definition
and functionality of the DNP Protocol cannot be made without express written agreement from the DNP Users
Group or its duly authorised party. In addition, no part of this document may be altered or revised or added to in
any form or by any means, except as permitted by written agreement with the DNP Users Group or a Party duly
authorised by the DNP Users Group.
The DNP Users Group has made every reasonable attempt to ensure the completeness and accuracy of this
document. However, the information contained in this manual is subject to change without notice, and does not
represent a commitment on the part of the DNP Users Group. An update program for DNP documents is
provided upon request by the DNP Users Group.
TRADEMARK NOTICES
DNP is a trademark of the DNP Users Group. Any brand and product names mentioned in this document are
trademarks or registered trademarks of their respective companies.
Copyright  2000 DNP Users Group. All rights reserved.
REVISION HISTORY
Version
Date
Revision Description
0.00A
8-Nov-1992
Preliminary release by Malcom Smith.
0.01
20-Aug-1993
Revised after review by J. Bhat.
0.01
01-Sep-1993
Corrections by C. Huene.
0.01
30-May-1997
Converted to MS Word 6.0
0.02
10-July-2000
Rewritten with additional clarification. References to Harris Corporation
removed. Removed transport services and responsibilities because transport is
function not layer. Removed glossary of terms and abbreviation sections.
DNP3 Transport Functions - Version 0.02
Page i
CONTENTS
1
OVERVIEW .......................................................................................................................................... 1
2
TRANSPORT FUNCTION DESCRIPTION......................................................................................... 1
2.1
2.2
Transport Header .............................................................................................................................. 1
2.1.1
FIN field................................................................................................................................ 1
2.1.2
FIR field ................................................................................................................................ 1
2.1.3
SEQUENCE field.................................................................................................................. 2
2.1.4
Rules ..................................................................................................................................... 2
Application Layer Data .................................................................................................................... 2
2.2.1
Rules ..................................................................................................................................... 2
2.3
Reception State Table....................................................................................................................... 3
2.4
Reception State Diagram .................................................................................................................. 4
2.5
Segmenting Example........................................................................................................................ 5
DNP3 Transport Functions - Version 0.02
Page ii
1 OVERVIEW
The size of a DNP3 application layer message fragment may be larger than the number of octets permitted in a
single data link layer frame. The transport function disassembles application layer fragments into data link
layer-sized data units for transmission and reassembles these pieces into the original application fragment on
reception.
At the transmission site, an application layer fragment is broken into smaller pieces, and a header is added
containing sequencing information for each piece. The header and application data form a transport layer
segment that is passed to the link layer. Segments are always passed one-at-a-time, in sequence, from the first to
the last. The link layer throttles or paces the acceptance of segments by returning an indication of success or
failure to send each segment.
Transport segment
Header
Application Layer Data
← 1 octet →
← from 1 to 249 octets →
At the receiving site, segments passed from the link layer are checked for sequencing by examining the header.
Any segments that are received out of order are discarded. Only when a complete application fragment is
assembled does the transport function notify the application layer that it is available.
2 TRANSPORT FUNCTION DESCRIPTION
2.1
Transport Header
The transport header consists of a single octet. The header is the first octet in a segment. A header is prepended
to each piece of application layer data before submission to the link layer for transmission, and upon receipt of a
segment from the link layer, the header is stripped away before assembly of an application fragment.
The transport header is composed of three fields as follows:
Header Bit Definitions
2.1.1
Bit #
7
6
Fields
FIN
FIR
5
4
3
2
1
0
SEQUENCE
FIN field
The FIN field is a single bit, which when set, indicates that this is the final or last segment in the fragment.
FIN = 0 indicates more segments follow.
FIN = 1 indicates the final segment in a series of segments.
2.1.2
FIR field
The FIR field is a single bit, which when set, indicates that this is the first segment in the fragment.
FIR = 0 indicates this is not the first segment in a series of segments.
FIR = 1 indicates this is the first segment in a series of segments.
DNP3 Transport Functions - Version 0.02
Page 1
2.1.3 SEQUENCE field
The SEQUENCE field is 6 bits wide. It is used to verify that segments are received in the correct order and
guards against duplicated or missing segments. It has a range of 0 to 63. Sequence numbers increment by one
count, modulo 64, for each segment in a series of segments that hold an application layer fragment. After
sequence number 63, the next value is 0.
Definition: The term “segment-series” is used to describe a series of transport segments where each segment
after the first has a sequence number incremented by one from the preceding segment.
2.1.4
Rules
1.
A segment-series may only begin with a segment having the FIR bit set.
2.
A segment-series ends with a segment having the FIN bit set.
3.
When a segment is received with the FIR bit set, any previously received, unterminated segment-series shall
be discarded and a new segment-series shall be started with the newly received segment as its first member.
4.
When no segment-series is in progress, any segment received without the FIR bit set shall be discarded.
5.
A segment with the FIR bit set may have any sequence number from 0 to 63 without regard to prior history.
Nevertheless, it is recommended that a transmitter increment the sequence number by one count (modulo
64), for segments with the FIR bit set, above the sequence number it placed in the previously transmitted
segment.
6.
After a segment-series has been started:
Each subsequent segment received must have a sequence number which is incremented by one (modulo 64)
from the preceding segment. A segment received that meets this requirement becomes the next member of
the segment-series. A segment received having the FIN bit cleared and the identical sequence number as the
preceeding segment shall be ignored. A segment received having the FIN bit set and the identical sequence
number as the preceeding segment, or a segment received containing any sequence number other than the
expected incremental number, shall be discarded and shall also cause the entire in-progress, segment-series
to be terminated and discarded.
7.
A segment-series may consist of a single segment having both FIR and FIN bits set.
8.
When a complete segment-series is assembled, only then may its application data be passed to the
application layer.
2.2
Application Layer Data
Each segment contains between 1 and 249 octets of application layer data.
2.2.1
Rules
1.
Customarily, every segment, except the last in a segment-series contains exactly 249 octets of application
layer data. The last segment only needs to be large enough to hold the remainder of the application data.
However, this is not a requirement. Any segment may contain between 1 and 249 octets. The transport
function in a receiving station must accept any sized segment and be able to properly reassemble the
application layer data.
2.
The application layer presents a buffer containing an application layer fragment to the transport function for
segmenting. The octets in the fragment buffer are numbered starting from 0 as illustrated in section 2.5.
The application data piece having octet number 0 is transported by the first segment, that is the segment
with its header’s FIR bit set and sequence number N. The next application data piece, if there is one, is then
placed into a segment having sequence number (N + 1) modulo 64. This pattern, where application data
pieces with lower octet numbers are placed into transport segments before pieces with higher octet numbers,
continues until the last piece is sent. At the receiving end, application layer fragments are reassembled in
the same order.
DNP3 Transport Functions - Version 0.02
Page 2
3.
Each segment transports a unique set of octets from an application layer fragment. The application data is
positioned within the segment immediately after the transport header. The application data octet with the
lowest octet number appears first, adjacent to the header, and is followed by the remainder of the application
data piece in octet order.
2.3
Reception State Table
Assume the transport function software has a fragment buffer where application data from the received segments
are stored before presenting the fragment to the application layer.
The software requires two states for proper operation.
1.
Idle state: The software is idle waiting for a segment to arrive with the FIR bit set.
2.
Assembly state: The fragment buffer holds application data from at least one segment. While in this
state, the software is awaiting additional segments to complete a fragment.
Keys for understanding the table:
•
X means don’t care.
•
SAME means the sequence number is identical to the sequence number in the segment immediately
preceeding this segment.
•
+1 means the sequence number is incremented by one count, modulo 64, from the sequence number in
the segment immediately preceeding this segment.
•
+M, 1 < M < 64 means the sequence number is incremented by more than one count and less than 64
counts from the sequence number in the segment immediately preceeding this segment.
If the
software
state is
Idle
Assembly
And the transport header in
the receive segment is
FIR
FIN
SEQ
0
X
X
1
1
X
1
0
X
0
0
0
1
SAME
SAME
0
0
+1
0
1
+1
0
X
+M
1 < M < 64
1
0
X
1
1
X
DNP3 Transport Functions - Version 0.02
then perform this action
Discard segment.
Dump contents of fragment buffer, add segment’s
data to fragment buffer and pass fragment buffer to
application layer.
Dump contents of fragment buffer and add
segment’s data to fragment buffer.
Ignore segment.
Discard segment.
Append segment’s data to contents of fragment
buffer.
Append segment’s data to contents of fragment
buffer and pass fragment buffer to application layer.
Discard segment.
Dump contents of fragment buffer and add
segment’s data to fragment buffer.
Dump contents of fragment buffer, add segment’s
data to fragment buffer and pass fragment buffer to
application layer.
and go to
this state
Idle
Idle
Assembly
Assembly
Idle
Assembly
Idle
Idle
Assembly
Idle
Page 3
2.4
Reception State Diagram
See text at beginning of section 2.3. The same applies to this diagram.
FIR=0,
FIN=X,
SEQ=X
Discard
segment
Idle
State
FIR=1,
FIN=1,
SEQ=X
FIR=1,
FIN=0,
SEQ=X
Dump contents
of fragment buffer
Pass fragment
buffer to application
layer
Dump contents
of fragment buffer
Discard
segment
Add segment
to fragment buffer
Append segment
to fragment buffer
FIR=0,
FIN=1,
SEQ=SAME
Add segment
to fragment buffer
Pass fragment
buffer to application
layer
FIR=1,
FIN=0,
SEQ=X
FIR=0,
FIN=1,
SEQ=+1
FIR=0,
FIN=X,
SEQ=+M,1<M<64
FIR=1,
FIN=1,
SEQ=X
Assembly
State
Ignore segment
FIR=0,
FIN=0,
SEQ=SAME
DNP3 Transport Functions - Version 0.02
FIR=0,
FIN=0,
SEQ=+1
Append segment
to fragment buffer
Page 4
2.5
Segmenting Example
The following example illustrates the transport function. Application layer octet numbers are shown inside the
elements. The letters “TH” stand for Transport Header. Octets are transmitted in left-to-right order.
Example Application layer fragment: 600 octets transported in 3 pieces
0
1
…
247 248 249 250
← 1st piece →
…
496 497 498 499
← 2nd piece →
…
598 599
← 3rd piece →
First transport segment:
0
TH
1
…
247 248
st
← 1 application data piece →
Transport header: FIR = 1, FIN = 0, SEQUENCE = n (any number 0–63, e.g.: 25).
Second transport segment:
249 250
…
496 497
nd
TH ← 2 application data piece →
Transport header: FIR = 0, FIN = 0, SEQUENCE = (n+1) modulo 64 (e.g.: 26).
Last transport segment:
498 499
…
598 599
rd
TH ← 3 application data piece →
Transport header: FIR = 0, FIN = 1, SEQUENCE = (n+2) modulo 64 (e.g.: 27).
DNP3 Transport Functions - Version 0.02
Page 5
DNP 3 Counter Objects
Proposed Change for “Delta Counter” Variations
May 31, 2001
Issue
The DNP Technical Committee has determined that Delta Counter variations for Counter Objects
•
•
•
Are not well defined,
Create a potential for unrecoverable loss of data, and
Provide no functionality not available through other Counter Object variations
Therefore, the Technical Committee is proposing to remove Delta Counter variations from DNP3
protocol.
Discussion
The DNP Technical Committee has received several inquiries regarding operations and definitions related
to Binary and Frozen Counters, objects 20, 21, 22, and 23. These have led to an internal review of counter
objects with the goal of producing a technical bulletin clarifying the issues presented.
DNP allows Counters to be reported as either Current or Delta values. The Current value of a Binary
Counter or Binary Counter Event point is the value of an underlying Counter at the time a read request is
processed. The Current value of a Frozen Counter or Frozen Counter Event point is the value of an
underlying Counter at the time that the most recent freeze request was processed. The Delta value of a
Counter point is the difference between the Current value at the time of read, and the Current value when
the Counter was last successfully reported to the master.
The Technical Committee has uncovered serious concerns regarding the use of “Delta Counters”. These
concerns are based on the following two facts:
1. A RTU cannot always determine that a master has received its most recently transmitted message. In
such a case, a retransmission is required to insure delivery.
2. A master cannot always determine if a message containing counter information has been previously
received.
The above example case occurs when RTU data is sent with application confirm services. The master
receives the message and transmits a confirm, but the confirm is not received at the RTU. Data contained
in the initial message is not identified by the RTU as having been delivered, and will eventually be
retransmitted. In systems that use Delta Counter variations, the master will receive two reports with the
same Delta value and incorrectly calculate the associated accumulation. An error of this type cannot occur
when Current value variations are used.
Summary and Resolution
The DNP Technical Committee would appreciate comments from any DNP User Group Member
regarding the proposal to remove Delta Counter variations from all Counter Objects. They are especially
interested in comments from companies, if any, that are using Delta Counters in an active system. If
accepted, this change has the potential of making existing implementations
non-compliant with DNP-2002.
Members should send their comments via Email to dnptech@acsatl.com. Please respond no later than
June 30, 2001. Barring significant objections, a technical bulletin as proposed will be issued.
DNP Technical Bulletin TB2001-001
Multiple Control Objects and Status Codes
Issues:
1
The DNP3 protocol permits a master to transmit a request containing multiple control objects, of type object 12 and
variation 1, in the same message to a slave. Likewise, provision exists for sending messages with multiple analog
output objects, of type object 41 and any variation, in the same request.
Many DNP3 slaves are able to queue or simultaneously output these objects. However, other devices can only
output to a limited number of points—possibly just a single point—and may not be able to process a request
containing a greater number of objects. DNP3’s Basic 4 documentation does not clearly explain how a device should
behave or respond to a request containing more output objects than the device permits.
The DNP3 Level 3 Implementation table, paragraph 3.3, specifies an incorrect qualifier code for object 12, variation
2. Qualifier codes 17 and 28 should be replaced with code 07.
When a DNP3 outstation detects an error in a control or analog output request, it must return a non-zero status code.
The existing status codes, 1 through 6, do not adequately describe all the error conditions, and additional codes are
needed.
2 Resolution:
2.1
Response Status Codes
New status codes 7, 8, 9 and 127 are defined and all status codes now have short identifier names. The complete list
of codes appears in the following table.
Code
Number
0
Identifier
Name
SUCCESS
HARDWARE_ERROR
LOCAL
TOO_MANY_OPS
NOT_AUTHORIZED
Request accepted, initiated, or queued.
Request not accepted because the operate message was received after the arm
timer timed out. The arm timer was started when the select operation for the
same point was received.
Request not accepted because no previous matching select request exists. (An
operate message was sent to activate an output that was not previously armed
with a matching select message.)
Request not accepted because there were formatting errors in the control
request (either select, operate, or direct operate).
Request not accepted because a control operation is not supported for this
point.
Request not accepted, because the control queue is full or the point is already
active.
Request not accepted because of control hardware problems.
Request not accepted because Local/Remote Switch is in Local position.
Request not accepted because too many operations requested.
Request not accepted because of insufficient authorization.
RESERVED
Reserved for future use.
UNDEFINED
Request not accepted because of some other undefined reason.
1
TIMEOUT
2
NO_SELECT
3
FORMAT_ERROR
4
NOT_SUPPORTED
5
ALREADY_ACTIVE
6
7
8
9
10 to
126
127
Description
2.2
Master Requirements
2.2.1
Select-Operate
If a master receives a response to a select request, function code 3, and
DNP Technical Bulletin TB2001-001
Multiple Control Objects and Status Codes
Page 1 of 1
15-December-2000
•
any of the objects contains a non-zero status,
•
any of the objects are missing from the response or
•
any of the IIN bits 2-0, 2-1, 2-2 or 2-4 are set,
then it shall not issue the subsequent operate command, function code 4. The slave’s behavior is not guaranteed
when a master violates this rule.
2.2.2
Configurable
If a master has the capability to send multiple objects (binary or analog) in a single control output request, it must be
configurable to send only one object per message.
2.2.3
Pattern Mask
If the master desires simultaneous execution of controls, it shall use a pattern control block and a pattern mask,
object 12 variations 2 and 3, respectively. There is no guarantee that multiple controls will execute simultaneously
unless a pattern control block and mask are used—and—the slave supports this type of operation.
2.3
Slave Requirements
2.3.1
Responses
The slave has the option to stop parsing the remainder of a request upon detection of the first error or continuing to
the end of the request.
When a slave receives a control or analog output request—select, operate or direct operate—and one or more of the
objects are unsuccessful, its response shall include one of these
•
No objects if the request contains an unsupported function code or object variation.
•
All of the objects.
•
All of the objects up to and including the first unsuccessful object. This is a truncated response.
Each object returned in the response shall contain the appropriate status code indication. The IIN bits 2-0, 2-1, 2-2
and 2-4 shall be set or cleared as applicable. Note that the IIN bits only need to reflect the state of the first error
detected.
Examples are presented in section 3.
2.3.2
Illegal Master Requests
If the master violates the rule in section 2.2.1 and issues an illegal operate command, the slave may take one of the
following actions:
•
Ignore the request and not operate any of the points.
•
Execute those objects for which it returned a zero status code.
2.3.3
Pattern Mask
Slave devices are not required to implement Pattern Control Blocks (object 12, variation 2) or Pattern Masks (object
12, variation 3); nevertheless, level 3 slave devices must be able to parse messages containing these.
2.4
Pattern Control Block
The correct qualifier code in the DNP3 Level 3 Implementation table, paragraph 3.3, for object 12, variation 2 is 07.
2.5
Device Profile
The Device Profile Document of each slave device shall contain a statement specifying the maximum number of
objects supported in a single request for objects 12 and 41. It shall also include a statement indicating whether it
supports pattern control block - pattern control mask operations, and if so, what restrictions exist.
DNP Technical Bulletin TB2001-001
Multiple Control Objects and Status Codes
Page 2 of 2
15-December-2000
3 Examples
The following table shows example responses from control or analog output requests containing four objects. These
objects are identified as A, B, C and D. The responses are identical regardless of whether the requests are select,
function code 3; operate, function code 4 or direct operate, function code 5.
Key: NR means Not Reported.
Response
Conditions in slave
when Request is received
No errors are detected, all objects successful.
The function code is not supported regardless of
which indexes the objects have.
The slave does not support the specific variation code
in the request.
Indexes for objects C and D are beyond the
maximum number of points installed in the slave.
Object B is already executing when this request
arrives.
The slave can only control one object at a time.
Object C is tagged or blocked to prevent its control.
The Remote/Local Switch is in the Local position.
A control output is requested and the Control Relay
Output Block in Object D’s request contains an
illegal control code.
An analog output is requested and the value in Object
D’s request exceeds the permitted level.
Obj
A
0
Status Codes
Obj
Obj
B
C
0
0
Obj
D
0
1.
5
0
IIN Bits
2. 2. 2.
0
1
2
0
0
0
2.
4
0
NR
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NR
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1
0
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NR
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NR
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1
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7
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8
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4
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4 Affected Documentation:
Basic 4 Object Library, Object 12, Variation 1: Add sections 2.3 and 2.2 from above to the “Narrative”. Replace
the listing of error codes with the table in section 2.1.
Basic 4 Object Library, Object 41, all variations: Add sections 2.3 and 2.2 from above to the “Description”.
Basic 4 Subset Definitions, Appendix A, Device Profile Document: In the section that begins with
“Sends/Executes Control Operations: Add three lines beneath DIRECT OPERATE – ACK as follows:
•
Maximum number of CROB (object 12, variation 1) objects supported in a single message ________.
•
Maximum number of analog output (object 41, any variation) objects supported in a single message ________.
•
Pattern Control Block and Pattern Mask (object 12, variations 2 and 3, respectively) supported. If so,
describe any restrictions.
•
CROB (object 12) and analog output (object 41) permitted together in a single message.
Basic 4 Subsets Definitions, Level 3 Implementation: The qualifier codes are replaced by a single code of 07 in
the implementation table, paragraph 3.3, for object 12, variation 2.
5 Changes to the Subset Level 1 and 2 Certification Procedures:
5.1
Paragraph 8.2.1.1 – Desired Behavior in both certification procedures
Change third bullet under device supports control operations to read, “The DUT responds to selecting an uninstalled
control point by returning an error response with IIN2-2 set and a status code of 4.”
DNP Technical Bulletin TB2001-001
Multiple Control Objects and Status Codes
Page 3 of 3
15-December-2000
5.2
Paragraph 8.2.1.2.3, step 2 – Test Procedure in both certification procedures
Change to read, “Verify that the DUT responds by returning an error response with IIN2-2 set and a status code of
4.”
5.3
Paragraph 8.2.2.1 – Desired Behavior in both certification procedures
Change first bullet under device supports control operations to read, “The DUT responds to a direct operate to an
uninstalled control point by returning an error response with IIN2-2 set and a status code of 4.”
5.4
Paragraph 8.2.2.2.2, step 2 – Test Procedure in both certification procedures
Change to read, “Verify that the DUT responds by returning an error response with IIN2-2 set and a status code of
4.”
5.5
Paragraph 8.2.4.1 – Desired Behavior in both certification procedures
After the second bullet, add a statement that says, “The following behavior assumes that the device supports control
operations:”
Add a bullet below the new statement that says, “The DUT responds to requests having more points than are
supported in a single message with a status code of 8 for at least the first point that is beyond the point count limit.”
Add a second bullet below the new statement that says, “The DUT responds to a select to an uninstalled control
point by returning an error response with IIN2-2 set and a status code of 4.”
5.6
Paragraph 8.2.4.2 – Test Procedure in both certification procedures
Replace items 1 through 6 as follows:
1.
Review the device’s profile document to understand how many control points are supported in a single
request. If this number is one, skip to step 7.
2.
Determine the number of installed points that can be successfully controlled in a single request. This
number shall be the smaller of
•
The number of controls supported in a single request
•
The number of installed control points
•
Sixteen
In a single request, issue a select to the above number of points using Object 12, Variation 1 and 16-bit
indexing (qualifier 0x28), a control code supported by the device, and an appropriate on time/off time.
3.
Verify that the DUT response has none of IIN2-0, IIN2-1, or IIN2-2 set and that each object returns a status
code of 0.
4.
Immediately issue a matching execute.
5.
Verify that the DUT response has none of IIN2-0, IIN2-1, or IIN2-2 set and that each object returns a status
code of 0.
6.
Verify that each of the selected controls operated. Note that controls may execute simultaneously or
sequentially one after the other.
7.
If the number of control objects supported in a single request is greater than or equal to either
•
The number of control objects that fit into a single frame or
•
The number of installed control points,
skip to step 13.
8.
In a single request, issue a select to at least one more point than is supported in a single request, each point
having a different index but otherwise able to be controlled, using Object 12, Variation 1 and 16-bit
indexing (qualifier 0x28), a control code supported by the device, and an appropriate on time/off time.
DNP Technical Bulletin TB2001-001
Multiple Control Objects and Status Codes
Page 4 of 4
15-December-2000
9.
Verify that the DUT response has none of IIN2-0, IIN2-1, or IIN2-2 set, that each object except the last
returns a status code of 0, and the last object returns a status code of 8.
10. If the DUT does not support direct operate, skip to step 13.
11. In a single request, issue a direct operate command to at least one more point than is supported in a single
request, each point having a different index but otherwise able to be controlled, using Object 12, Variation
1 and 16-bit indexing (qualifier 0x28), a control code supported by the device, and an appropriate on
time/off time.
12. Verify that the DUT response has none of IIN2-0, IIN2-1, or IIN2-2 set, that each object except the last
returns a status code of 0 and the last object returns a status code of 8. Verify that all except the last control
point operated.
13. In a single request, issue a select to one installed control point and to one point that is not installed using
Object 12, Variation 1 and 16-bit indexing (qualifier 0x28), a control code supported by the device, and an
appropriate on time/off time. The installed point should be the first object in the request.
14. Verify that the DUT response has IIN2-2 bit set, that the status code returned for the installed point is 0 and
the status code returned for the non-installed point is 4.
5.7
Paragraph 8.4.1.1 - Desired Behavior in both certification procedures
Change third bullet under device supports analog output operations to read, “The DUT responds to selecting an
uninstalled analog output point by returning an error response with IIN2-2 set and a status code of 4.”
5.8
Paragraph 8.4.1.2.3, step 2 – Test Procedure in both certification procedures
Change to read, “Verify that the DUT responds by returning an error response with IIN2-2 set and a status code of
4.”
5.9
Paragraph 8.4.2.1 – Desired Behavior in both certification procedures
Change second bullet under device supports analog output operations to read, “The DUT responds to a direct
operate to an uninstalled analog output point by returning an error response with IIN2-2 set and a status code of 4.”
5.10
Paragraph 8.4.2.2.2, step 2 – Test Procedure in both certification procedures
Change to read, “Verify that the DUT responds by returning an error response with IIN2-2 set and a status code of
4.”
5.11
Paragraph 8.4.4.1 – Desired Behavior in both certification procedures
After the second bullet, add a statement that says, “The following behavior assumes that the device supports analog
output operations:”
Add a bullet below the new statement that says, “The DUT responds to requests having more points than are
supported in a single message with a status code of 8 for at least the first point that is beyond the point count limit.”
Add a second bullet below the new statement that says, “The DUT responds to a select to an uninstalled analog
output point by returning an error response with IIN2-2 set and a status code of 4.”
5.12
Paragraph 8.4.4.2 – Test Procedure in both certification procedures
Replace items 1 through 5 as follows:
1.
Review the device’s profile document to understand how many analog output points are supported in a
single request. If this number is one, skip to step 7.
2.
Determine the number of installed points that can be successfully controlled in a single request. This
number shall be the smaller of
•
The number of controls supported in a single request
•
The number of installed control points
DNP Technical Bulletin TB2001-001
Multiple Control Objects and Status Codes
Page 5 of 5
15-December-2000
•
Sixteen
In a single request, issue a select to the above number of points using Object 41, Variation 2 and 16-bit
indexing (qualifier 0x28), a control code supported by the device, and a value supported by the device
3.
Verify that the DUT response has none of IIN2-0, IIN2-1, or IIN2-2 set and that each object returns a status
code of 0.
4.
Immediately issue a matching execute.
5.
Verify that the DUT response has none of IIN2-0, IIN2-1, or IIN2-2 set and that each object returns a status
code of 0.
6.
Verify that each of the selected analog outputs occurred. . Note outputs may occur simultaneously or
sequentially one after the other.
7.
If the number of control objects supported in a single request is greater than or equal to either
•
The number of control objects that fit into a single frame or
•
The number of installed control points,
skip to step 13.
8.
In a single request, issue a select to at least one more point than is supported in a single request, each point
having a different index but otherwise able to be outputted, using Object 41, Variation 2 and 16-bit
indexing (qualifier 0x28) and an appropriate value.
9.
Verify that the DUT response has none of IIN2-0, IIN2-1, or IIN2-2 set, that each object except the last
returns a status code of 0, and the last object returns a status code of 8.
10. If the DUT does not support direct operate, skip to step 13.
11. In a single request, issue a direct operate command to at least one more point than is supported in a single
request, each point having a different index but otherwise able to be outputted, using Object 41, Variation 2
and 16-bit indexing (qualifier 0x28) and an appropriate value.
12. Verify that the DUT response has none of IIN2-0, IIN2-1, or IIN2-2 set, that each object except the last
returns a status code of 0 and the last object returns a status code of 8. Verify that all except the last analog
output point outputted the new value(s).
13. In a single request, issue a select to one installed analog output point and to one point that is not installed
using Object 41, Variation 2 and 16-bit indexing (qualifier 0x28) and an appropriate value. The installed
point should be the first object in the request.
14. Verify that the DUT response has IIN2-2 bit set, that the status code returned for the installed point is 0 and
the status code returned for the non-installed point is 4.
6 Status:
Approval Technical Committee (Feb-2001).
DNP Technical Bulletin TB2001-001
Multiple Control Objects and Status Codes
Page 6 of 6
15-December-2000
DNP Technical Bulletin 2000-001
Sequential File Transfer Objects
1
Introduction
The following document provides a replacement implementation for DNP File Transfer as
described in the Basic 4 document set. This bulletin is intended to address sequential file transfer
only, not random file access. The following functionality is provided:
•
•
•
•
Simple reliable transfer of bulk data either up or down the communications chain.
Straightforward implementation.
Graduated features/complexity (by implementing additional objects).
Bandwidth management by limiting block sizes and allowing requested objects to be treated
as events that can appear an arbitrary period after they were originally requested.
Legacy implementations of Object 70 Variation 1 cannot be relied upon to provide consistent
implementation or interoperable file transfer capability.
This bulletin describes replacement objects and methods that should be used instead of the
existing Object 70 Variation 1.
FIFO and other types of dynamic files may be transferred using the sequential file transfer
mechanisms described in this bulletin. However, a dynamic file must be treated as a static file
during the time between opening the file and the corresponding file Close or Abort. After the file
is closed, the dynamic file may be modified as the device so chooses.
While this bulletin addresses sequential file transfer only, random access file support, and other
file access techniques, will be supported in the future through the specification of additional
objects.
2
Notes
The following notes apply to all sections of the document
•
•
•
•
•
All String offsets are relative to the start of the object; i.e. the first octet following the object
header.
All data shown in examples is expressed in Decimal unless preceded by 0x indicating
Hexadecimal.
All Status objects defined herein are treated as events when sent from an outstation in a
response, and may be returned an arbitrary period after requested.
As is the case when any DNP event is sent from an outstation, it is a requirement that an
application confirm be requested by the outstation when sending file status events.
Some of the following descriptions refer to timeout mechanisms used when handling file
operations. It should be noted that file handling timeouts and the generation of file status
events is independent of communication handling timeouts. As is the case for generation of
any DNP event, the communication processing that is responsible for the delivery of the
events (eg. through polling or unsolicited reporting) and collection of confirms is independent
of the generation of the event.
Sequential File Transfer Objects
26 January 2000
DNP Technical Bulletin 2000-001
Page 1
3
Application Layer Function Codes
Additional application layer function codes are added to support authentication and file specific
operations. They are defined as follows.
Function
Code
25
26
27
28
29
30
4
Table 1
Description
Open a File
Close a File
Delete a File
Get File Info
Authenticate
Abort
Authentication
Devices that do not support authentication must not support this object.
Before proceeding with secure transactions the application must obtain an Authentication Key
from the end device. An Authentication Key is required to perform an Open or Delete command
as described in the next section. It expires as soon as it is used.
A new object is defined to support the process as follows.
b7
Table 2
Object Header
Object 70
Variation 2
b7
Qualifier 0x5B
b0
b7
Range Field (=1)
b0
b15
Number of Octets in object
b0
b15
Authentication Object Format
User Name Offset
b0
b15
User Name Size
b0
b15
Password Offset
b0
b15
Password Size
b0
b31
Authentication Key
b0
bn
User Name Octets
b0
bn
Password Octets
b0
b7
b0
b0
The User Name Offset field is a 16 bit parameter which specifies the zero-based start of the
name octets relative to the start of the object excluding the header.
The User Name Size field is a 16 bit parameter which specifies the number of name octets.
The Password Offset field is a 16 bit parameter which specifies the zero-based start of the
password octets relative to the start of the object excluding the header.
Sequential File Transfer Objects
26 January 2000
DNP Technical Bulletin 2000-001
Page 2
The Password Size field is a 16 bit parameter which specifies the number of Password octets.
Using the Offset and Size technique effectively provides a jump-table to the strings included in
the object definition.
The Authentication Key field is a 32 bit number that is maintained by the outstation and uniquely
specifies the permissions granted by the authentication process.
User Name Octets are the octets of the user name.
Password Octets are the octets of the password.
Issuing an authentication request to the Authentication Object (obj 70 var 2) generates an
Authentication Key. A user name and password are passed to the outstation in the request. The
outstation responds with a pseudo random Authentication Key. The application can then use this
key for exactly one secure transaction. The outstation maintains the relationship between the key
and the permitted transactions. It is possible for there to be a set of user names and passwords
that have different permissions. A unique Authentication Key may be obtained for each username
via a separate authentication request.
If authentication fails, the response will contain a zero value for the Authentication Key, which
implies world (or guest) permissions. An application can issue secure transaction requests using
a zero value Authentication Key. It is up to the end device to interpret how to handle this. For
example, if the end device provides user authentication it could permit reading of some files but
exclude writing and deleting files.
This technique also allows a mechanism for using secure dialogs without performing the
authentication step. This is acceptable if and only if the end device is permissive and allows it.
To retrieve an Authentication Key the host issues an authentication request to the authentication
object as follows
0xC0 29 70 02 0x5B 01 nn nn … (object data)
The object data includes the user name and password to be authenticated. The
Authentication Key field is not used in the request and must be zero.
The outstation responds with
0xC0 129 IINs 70 02 0x5B 01 nn nn … (object data)
The response contains the newly generated Authentication Key in the Authentication Key field
and for security purposes the user name and password fields are null.
5
Open, Close, Delete and Abort.
Open and Delete are secure transactions. A valid Authentication Key is required to successfully
perform these transactions and expires as soon as it is used. A zero value for the Authentication
Key implies world (or guest) permissions.
To support the Open, Close, Delete and Abort functionality two objects are defined: The File
Command Object (obj 70 var 3), and the File Command Status Object (obj 70 var 4).
The File Command Object is used to initiate Open or Delete operations.
Sequential File Transfer Objects
26 January 2000
DNP Technical Bulletin 2000-001
Page 3
The File Command Status Object is used to indicate the success of Open, Close, Delete and
Abort commands and to return a file handle during opens. It is also used to initiate a file close or
abort using a previously acquired file handle.
The details of these objects are described in subsequent sections.
5.1
File Command Object
The File Command Object (obj 70 var 3) is used to facilitate file opens and deletes. It is defined
as follows.
b7
Table 3
Object Header
Object 70
Variation 3
B7
Qualifier 0x5B
b0
b7
Range Field (=1)
b0
b15
Number of Octets in object
b0
b15
File Command Object Format
File Name Offset
b0
b15
File Name Size
b0
b47
Time of Creation
b0
b15
Permissions
b0
b31
Authentication Key
b0
b31
File Size
b0
b15
Operational Mode
b0
b15
Maximum Block Size
b0
b15
Request ID
b0
bn
File Name Octets
b0
b7
b0
b0
The File Name Offset field is a 16 bit parameter which specifies the zero-based start of the file
name octets relative to the start of the object excluding the header.
The File Name Size field is a 16 bit parameter which specifies the number of file name octets.
The file name offset and file name size fields form a jump-table allowing direct access to the file
name string at the end of the object. Offset is relative to the beginning of the object (zero based)
excluding the header.
The Time of Creation field is a 48 bit parameter that represents the DNP time of creation of the
file represented as the number of milliseconds since midnight January 1, 1970. A value of zero in
this field indicates that the time of creation of the file is unknown.
The Permissions field is a 16 bit parameter whose value is defined in Table 4.
Table 4
Permission
Sequential File Transfer Objects
26 January 2000
Bit Fields
DNP Technical Bulletin 2000-001
Page 4
Owner Read Allowed:
Owner Write Allowed:
Owner Execute Allowed:
Group Read Allowed:
Group Write Allowed:
Group Execute Allowed:
World Read Allowed:
World Write Allowed:
World Execute Allowed:
0x0100
0x0080
0x0040
0x0020
0x0010
0x0008
0x0004
0x0002
0x0001
The Permissions field contains a UNIX-style file access permission bit field. The use of this field
is optional. Devices may update any of these fields in response to Read or Info requests if they
can provide correct values for these fields. The relevant action is permitted if the bit is set, and
inhibited if the bit is clear (e.g.: set Permission to 0x1FF to indicate no restrictions).
If the file is opened for writing, the Time of Creation and Permissions fields of the File Command
Object (obj 70 var 3) shall be used as attributes for the new file. Otherwise the Time of Creation
and Permissions fields must be zero when using this object.
The Authentication Key field is a 32 bit parameter that facilitates secure transaction
authentication. The key is obtained by issuing an Authentication Request (Function code 29) to
the Authentication Object (obj 70 var 2) (see section 4). A value of 0 in this field indicates a
permissive access level analogous to anonymous, guest or world permissions in various file
systems. Devices that do not support authentication must ignore this field.
The File Size field is a 32 bit parameter representing the number of octets contained in the file.
This is particularly important when opening a file so that both ends have the opportunity to
allocate adequate buffers. During an open for write the outstation may prepare its buffers
appropriately. During an open for read the file size must be zero and is ignored by the outstation.
If end of file is indicated to a device receiving a file, before the expected File Size is satisfied (by
receiving the Last Flag in the File Transport Object – see Section 6.2), the receiving device shall
treat the file as completely received and shall not consider this to be an error condition. However,
if the received file exceeds the expected File Size, the receiving device may treat this an error
and reject the transfer.
A file size of 0xffffffff is allowed and indicates that the actual file size is unknown. Its use is
allowable only when the value is truly not known. Devices are not required to accept an unknown
file size. Devices may reject any request that exceeds the device’s resource limits. In such a case
the two devices will not inter-operate.
The Operational Mode field is a 16 bit parameter denoting the mode a file should be opened in.
It is not used with the delete function, nor with function codes not requiring a file open (and must
be zero in those cases). Values for this field are defined as shown in the following table.
Mode Value
0x00
0x01
0x02
0x03
Sequential File Transfer Objects
26 January 2000
Table 5
Description
Null
Read
Write
Append
(Not required to be supported in a minimum
implementation)
DNP Technical Bulletin 2000-001
Page 5
The Maximum Block Size field is a 16 bit parameter. For Read Operations it specifies the
maximum number of octets an outstation is allowed to return in a file block, in response to a read
request. For Write Operations it specifies the maximum number of octets that will be sent in a
write request block.
The Request ID field is a 16-bit parameter whose value is arbitrarily assigned by the host and
sent in a request. The outstation device must remember this value and copy it into the Request
ID field of the corresponding response. This permits the host to correlate responses with their
requests when multiple files are simultaneously opened in the same device.
File Name Octets are the octets of the file name. They fully reference the file (including path
within the device).
5.2
File Command Status Object
The File Command Status Object (obj 70 var 4) is used as a response to Open, Close, Delete
and Abort commands, to facilitate closing a previously opened file, and to abort a file transfer in
progress. It can also be used as an Error response for a Get File Info command.
When files are opened they are assigned a unique file handle that is used to reference the file
during future operations. To Close a previously opened file, issue a Close command (function
code 26) using the File Command Status Object (obj 70 var 4) with the appropriate file handle.
b7
Table 6
Object Header
Object 70
Variation 4
b7
Qualifier 0x5B
b0
b7
Range Field (=1)
b0
b15
Number of Octets in object
b0
b31
File Command Status Object Format
File Handle
b0
b31
File Size
b0
b15
Maximum Block Size
b0
b15
Request ID
b0
b7
Status
b0
bx
Optional ASCII Characters
b0
b7
b0
b0
The File Handle field is a 32 bit parameter that provides a numeric identifier of the file opened. Its
value is arbitrary and provided by the end device but must be unique to the outstation DNP
address. It can be reused after a corresponding close is issued. Other operations will reference
this identifier.
The File Size field is a 32 bit parameter that is used to return the file size when a file has been
opened for read, i.e. when Operational Mode 0x01 is used in the File Command Object (obj 70
var 3). The value of this field is undefined in all other cases and must be zero.
Sequential File Transfer Objects
26 January 2000
DNP Technical Bulletin 2000-001
Page 6
The Maximum Block Size field is a 16 bit parameter that is used to return the maximum block
size that the outstation will return. This value should be less than or equal to the value set in the
Maximum Block Size field of the File Command Object. For Read Operations it specifies the
maximum number of octets that the outstation will return in a file block, in response to a read
request. For Write Operations it specifies the maximum number of octets that will be accepted by
the outstation in a write request block.
The Request ID field is a 16 bit parameter. It must be returned in each File Command Status
Object as the value of the Request ID field specified in the File Command Object or File
Descriptor Object for the corresponding file request.
The Status field is a 8 bit parameter that is used to return the status of the operation and must be
set to zero by the initiating station. The responding station reports any error conditions in this
field. The values for this field are defined in Table 7.
Optional ASCII Characters may be appended to the object after the status code, and are a
printable ASCII string that may be used to provide additional error information for any error
condition.
Table 7
Value of
Status Field
0x00
0x01
0x02
0x03
0x04
0x05
0x06
0x07
Name
Usage
•
•
•
•
•
•
•
•
0x08
Operation Completed Successfully
Permission Denied
Invalid Mode
File not found
File locked by another user
Open File Count Exceeded
File Handle Invalid
Requested block size not
supported for writes
Lost Communications
0x09
Can’t Abort
•
Reserved
Other
•
0x0A – 0x0F
0xFF
•
Requested operation successful
Authenticated user not allowed to access file
Unsupported or unknown Operational Mode
Requested file does not exist
Requested file already in use
Too many files open
Attempting to close a file that is not open
Outstation cannot write blocks of requested
size
Intermediate device lost communications with
end device
File transaction Abort was not successful. File
is closed and unusable.
Any error not listed above (optional ASCII
string may provide additional information)
Note: A minimal implementation may restrict the number of open files to one.
Note: The File Command Status Object (obj 70 var 4) is treated as an event when it is generated
after an Open, Close, Abort or Delete command, so that it can be either polled for specifically or
assigned to class 1, 2, or 3. It is also acceptable to return it in the response to a request if the
results are immediately known.
5.3
Opening a File
To open a file issue an Open command (function code 25) to the File Command Object (obj 70
var 3) passing the correct file name, size, block size, permissions and Authentication Key as
follows
0xC0 25 70 03 0x5B 01 nn nn … (object data)
Sequential File Transfer Objects
26 January 2000
DNP Technical Bulletin 2000-001
Page 7
To open the file for read, set the Operation Mode to read (0x01), and File Size to zero.
To open the file for write, set the Operation Mode to write (0x02).
If the file is opened for writing it shall be truncated to zero length and the Time of Creation and
Permissions fields of the File Command Object shall be used as attributes for the new file.
Otherwise the Time of Creation and Permissions fields must be zero.
Note: the file must be fully described as in
Path\FileName
The outstation responds with a File Command Status Object (obj 70 var 4) with the assigned file
handle and status code as follows
0xE0 129 IINs 70 04 0x5B 01 nn nn … (object data)
A status code of zero indicates that the file was successfully opened. The application should
use the returned file handle in future references to the file until it is closed.
A non zero status code indicates that the file was not successfully opened, and the file handle
value is invalid.
If the file was opened for read, the File Size field indicates the size of the file. If the file was
opened for write the File Size field reports zero.
The outstation has requested the host Confirm the response containing an event, so the host
responds as follows
0xC0 00
5.4
Closing a File
To Close a file, issue a Close command (function code 26) to the File Command Status Object
(obj 70 var 4) as follows
0xC0 26 70 04 0x5B 01 nn nn … (object data)
The File handle field should be set to the value assigned in the previous open. Status must be set
to zero. The outstation responds with
0xE0 129 IINs 70 04 0x5B 01 nn nn … (object data)
The object data shall be an echo of the request with the status field set to the appropriate value
(e.g. file does not exist, permission denied, etc.) A status code of zero indicates that the file was
successfully closed.
The outstation has requested the host Confirm the response containing an event, so the host
responds as follows
0xC0 00
Note: If there is no activity referencing a file handle for a configurable length of time the
outstation must do an automatic close on the file. The timeout value must be configurable up to 1
hour. When this condition occurs the outstation will send a File Transport Status Object (obj 70
var 6) using a status code value of file handle expired (0x02). The final state of the file closed
under this condition is undefined.
Note: The final state of a file that is closed after receiving a File Transport Status Object (obj 70
var 6) with a non-zero status code value is also undefined.
Sequential File Transfer Objects
DNP Technical Bulletin 2000-001
26 January 2000
Page 8
Note: If the host chooses to end the operation for any reason including a timeout it must send a
close to the outstation to release the file for further use.
5.5
Deleting a File
To delete a file, issue a Delete command (function code 0x1B) to the File Command Object (obj
70 var 3) as follows
0xC0 27 70 03 0x5B 01 nn nn … (object data)
Operation mode in the File Command Object must be set to zero.
The outstation shall respond with a File Command Status Object (obj 70 var 4) with the file
handle value of zero and the status code set to the appropriate status value (e.g. file does not
exist, permission denied, etc.) as follows
0xE0 129 IINs 70 04 0x5B 01 nn nn … (object data)
A status code of zero indicates that the file was successfully deleted. For more information on
status codes see Table 7.
The outstation has requested the host Confirm the response containing an event, so the host
responds as follows
0xC0 00
Note: If a file is open while issuing a delete command a File Command Status Object (obj 70 var
4) shall be returned with a status code of “File locked by another user” (0x04).
5.6
Aborting a File Transfer
To Abort a file transfer, issue an Abort command (function code 30) to the File Command Status
Object (obj 70 var 4) as follows
0xC0 30 70 04 0x5B 01 nn nn … (object data)
The File handle field should be set to the value assigned in the previous open. Status must be set
to zero. The outstation responds with
0xE0 129 IINs 70 04 0x5B 01 nn nn … (object data)
The object data shall be an echo of the request with the status field set to the appropriate value
(e.g. file does not exist, can’t abort, etc.) A status code of zero indicates that the file transfer was
successfully aborted.
The outstation has requested the host Confirm the response containing an event, so the host
responds as follows
0xC0 00
Note: If Abort is supported by a device, then upon receiving an Abort command the device must
terminate the file transfer indicated by the File Command Status Object and close the file. If a
device does not support Abort, the device must return a “Can’t Abort” status code in a File
Command Status Object (obj 70 var 4).
Note: To completely recover a file after an Abort, in all circumstances, it may be necessary for
the device to double-buffer the file during file transfer operations. If a file transfer Abort results in
Sequential File Transfer Objects
26 January 2000
DNP Technical Bulletin 2000-001
Page 9
an unusable file the device must return a “Can’t Abort” status code in a File Command Status
Object (obj 70 var 4).
6
Data Transfer
Two objects are defined to support data transfer. The first is a File Transport Object (obj 70 var
5). The second is the File Transport Status Object (obj 70 var 6).
6.1
File Transport Object
The File Transport Object (obj 70 var 5) is defined as follows.
b7
Table 8
Object Header
Object 70
Variation 5
b7
Qualifier 0x5B
b0
b7
Range Field (=1)
b0
b15
Number of Octets in object
b0
b31
File Transport Object Format
File Handle
b0
b7
b31
b30
LAST
Bn
Block Number
Data Octets
b0
b0
b0
b0
The File Handle field is a 32 bit parameter that provides a numeric identifier of the file opened. It
is obtained by opening the file using the File Command Object (obj 70 var 3) (see sections 4-5).
The Block Number field is a 31 bit parameter plus a 1 bit Last Flag. The block number starts at
zero and increments by one for each block read or written. The size of the data portion is not
relevant and need not be the same from block to block. It is limited by the maximum block size
field passed in the File Command Object (obj 70 var 3) during the open process. The Last Flag is
set to denote the indicated block number is the last block, and cleared to denote the indicated
block number is not the last block.
The Data Octets represent the information to be transferred.
Note: Using file handle qualification and block number allows multiple read/write operations to
different files on the same device, concurrently.
Note: The File Transport Object (Obj 70 var 5) is treated as an event for file read responses so
that it can be polled for specifically, assigned to class 1, 2, or 3, or sent in an unsolicited
response. It is also acceptable to return it in the response to a request if the results are
immediately known.
Sequential File Transfer Objects
26 January 2000
DNP Technical Bulletin 2000-001
Page 10
6.2
File Transport Status Object
The File Transport Status Object (obj 70 var 6) is defined as follows.
b7
Table 9
Object Header
Object 70
Variation 6
b7
Qualifier 0x5B
b0
b7
Range Field (=1)
b0
b15
Number of Octets in object
b0
b31
File Transport Status Format
File Handle
b0
b7
b31
b30
LAST
Block Number
b0
b0
b0
b7
Status Code
b0
Bx
Optional ASCII Characters
b0
The File Handle field is a 32 bit parameter that provides a numeric identifier of the file opened. It
is the value originally obtained by opening the file using the File Command Object (obj 70 var 3)
(see sections 4-5).
The Block Number field is a 31 bit parameter plus 1 bit Last Flag, corresponding to the Block
Number and Last Flag in a File Transport Object for which this object is reporting status. The
block number sent by the initiating station starts at zero and increments by one for each block
read or written. The Last Flag is set to denote the indicated block number is the last block, and
cleared to denote the indicated block number is not the last block.
The Status field is an 8 bit parameter that is used to return the status of a corresponding File
Transport Object operation. The responding station reports any error conditions in this field. The
values for this field are defined as follows:
Table 10
Value of
Name
Usage
Status Field
0x00
Operation Completed Successfully • File Transport Object successfully written
0x08
Lost Communications
• Intermediate device lost communications with
end device
0x10
No Previous Matching Open
• File handle does not reference an open file
0x11
Handle has Expired.
• File previously closed due to inactivity timeout
0x12
Buffer Overrun.
• Too much file data received to process
0x13
Fatal Error, File Unusable
• File system error
0x14
Block Number Out Of Sequence
• Already received data with this block number
• Missing (skipped) block number in sequence
0x15 – 0x1F Reserved
0xFF
Other
• Any error not listed above (optional ASCII string
may provide additional information)
Note: The File Transport Status Object (obj 70 var 6) is treated as an event and can be polled for
directly or assigned to class 1,2, or 3. Alternatively it can be reported via unsolicited response or
in response to the request if the results are immediately known.
Sequential File Transfer Objects
26 January 2000
DNP Technical Bulletin 2000-001
Page 11
Note: Any optional data appended to the object after the status code is a printable ASCII string
that is used to provide additional error information.
When any file status changes it is reported using a File Transport Status Object (obj 70 var 6) as
an event.
For example, when a file inactivity timer expires, the outstation shall generate an event using the
File Transport Status Object with status code 0x11 “Handle has Expired”. This event will then be
returned on the next poll or may be sent as an unsolicited response. After the event is
generated, the outstation is no longer required to retain information about the file being opened.
Any subsequent access to the file results in a File Transport Status Object with status code 0x10
“No Previous Open”.
The File Transport Status Object provides flow control and bandwidth management when
performing file write operations because
• It is required/guaranteed that the end device sends it.
• Normal polling continues while waiting for it.
• A configurable timeout limits how long to wait.
6.3
Writing Data
•
•
•
•
•
•
To write a file: Open the file in Write mode, providing authentication information (see
section 4).
Perform write to the File Transport Object (obj 70 var 5).
Wait for a File Transport Status Object (obj 70 var 6) Event with the matching file handle
and block number.
Assuming the operation was successful increment the block number and write the next
block.
When writing the last block set the Last Flag.
Close the file using the File Operation Status Object (obj 70 var 4) and file handle
returned in the open command.
A typical sequence is:
Table 11
Operation Sequence
Application Layer Octets
Open
0xC0 25 70 03 0x5B….(object data)
Open Response
0xE0 129 IINs 70 04 0x5B….(object data)
Confirm
0xC0 00
Write (Block 0x00000000)
0xC1 02 70 05 0x5B….(object data)
Null Response
0xC1 129 IINs
N Polls
0xC2 01 Class poll
Get Status Event (Block (0x00000000)
0xE2 129 IINs (data) Object 70 var 06
Confirm
0xC2 00
Sequential File Transfer Objects
26 January 2000
DNP Technical Bulletin 2000-001
Page 12
Write (Block 0x00000001)
0xC3 02 70 05 0x5B….(object data)
Null Response
0xC3 129 IINs
N Polls
0xC4 01 Class poll
Get Status Event (Block 0x00000001)
0xE4 129 IINs (data) Object 70 var 06
Confirm
0xC4 00
Write (Last Block 0x80000002)
0xC5 02 70 05 0x5B….(object data)
Null Response
0xC5 129 IINs
N Polls
0xC6 01 Class poll
Get Status Event (Last Block
0x80000002)
0xE6 129 IINs (data) Object 70 var 06
Confirm
0xC6 00
Close
0xC7 26 70 04 0x5B….(object data)
Returns Status In Status Object
0xE7 129 IINs 70 04 0x5B….(object data)
Confirm
0xC7 00
Note: If there is an error during the above operations including a file operation timeout, the
device shall return the appropriate status object with status code. . Under error conditions the file
must be implicitly closed by the outstation and the file contents must be considered
indeterminate. Upon receiving a File Transport Status Object (obj 70 var 6) with a non-zero status
code, the referenced file handle becomes invalid.
6.4
Reading Data
To Read a file
• Open the file in Read mode, providing authentication information, as described in section
4.
• Perform a read to the File Transport Object (obj 70 var 5).
• Wait for the response.
• Assuming the operation was successful increment the block number and read the next
block.
• When the Last Flag is set in the response, close the file using the File Operation Status
Object (obj 70 var 4) and file handle returned in the open command.
A typical sequence is:
Sequential File Transfer Objects
26 January 2000
DNP Technical Bulletin 2000-001
Page 13
Table 12
Operation Sequence
Application Layer Octets
Open
0xC0 25 70 03 0x5B….(object data)
Open Response
0xE0 129 IINs 70 04 0x5B….(object data)
Confirm
0xC0 00
Read (Block 0x00000000)
0xC1 01 70 05 0x5B….(object data)
Null Response
0xC1 129 IINs
N Polls
0xC2 01 Class poll
N+1 Poll
0xC3 01 Class poll
Poll response (File Data returned as
event)
0xE3 129 70 05 0x5B….(object data)
Confirm
0xC3 00
Read (Block 0x00000001)
0xC4 01 70 05 0x5B….(object data)
Null Response
0xC4 129 IINs
N Polls
0xC5 01 Class poll
N+1 Poll
0xC6 01 Class poll
Poll response (File Data returned as
event)
0xE6 129 70 05 0x5B….(object data)
Confirm
0xC6 00
Read (Block 0x00000002)
0xC7 01 70 05 0x5B….(object data)
Null Response
0xC7 129 IINs
N Polls
0xC8 01 Class poll
N+1 Poll
0xC9 01 Class poll
Poll response:File Data returned as
event with Last Flag set
0xE9 129 70 05 0x5B….(object data)
Confirm
0xC9 00
Close
0xCA 26 70 04 0x5B….(object data)
Returns Status In Status Object
0xEA 129 IINs 70 04 0x5B....(object data)
Confirm
0xCA 00
Sequential File Transfer Objects
26 January 2000
DNP Technical Bulletin 2000-001
Page 14
Note:
in read requests there are no data octets included in the File Transport Object
(obj 70 var 5).
Note: If there is an error during the above operations, including a file operation timeout, the
device shall return the appropriate status object with status code. Note that a File Transport
Status Object (obj 70 var 6) should be returned on error, instead of a File Transport Object (obj
70 var 5). Under error conditions, the file must be implicitly closed by the outstation and the host,
and file contents at the host must be considered indeterminate. Upon receiving a File Transport
Status Object (obj 70 var 6) with a non-zero status code the referenced file handle becomes
invalid.
7
Retrieving File Information
The File Descriptor Object (obj 70 var 7) is used to get information about a file. It is defined as
follows:
Table 13
Object Header
b7
b0
Object 70
b7
b0
Variation 7
B7
Qualifier 0x5B
b0
b7
Range Field (=1)
b0
b15
Number of Octets in object
b0
b15
File Descriptor Object Format
File Name Offset
b0
b15
File Name Size
b0
b15
File Type
b0
b31
File Size
b0
b47
Time of Creation
b0
b16
Permissions
b0
b15
Request ID
b0
bn
File Name Octets
b0
The File Name Offset field is a 16 bit parameter which specifies the zero-based start of the file
name octets relative to the start of the object excluding the header.
The File Name Size field is a 16 bit parameter which specifies the number of file name octets.
The file name offset and file name size fields form a jump-table allowing direct access to the file
name string at the end of the object. Offset is relative to the beginning of the object (zero based)
excluding the header.
The File Type field is a 16 bit parameter used to differentiate between simple files and
directories. A zero value indicates a directory. A value of 1 indicates a simple file.
The File Size field is a 32 bit parameter. For a simple file type it represents the number of octets
contained in the file. For a directory file type it indicates the number of entries in the sub-directory,
excluding any links to itself or its parent directory.
Sequential File Transfer Objects
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DNP Technical Bulletin 2000-001
Page 15
The Time of Creation field is a 48 bit parameter that represents the DNP time of creation of the
file represented as the number of milliseconds since midnight January 1, 1970.
The Permissions field is a 16 bit parameter whose values are defined in Table 4 (see section
5.1)
The Request ID field is a 16-bit parameter whose value is arbitrarily assigned by the host. The
outstation device must remember this value and copy it into the Request ID field of the
corresponding response. This permits the host to correlate responses with their requests when
information on multiple files is requested in the same device.
File Name Octets are the octets of the file name. They fully reference the file (including path
within the device).
Note: The File Descriptor Object (obj 70 var 7) is treated as an event when it is generated after a
Get File Info command, so that it can be either polled for specifically or assigned to class 1, 2, or
3. It is also acceptable to return it in the response to a request if the results are immediately
known.
7.1
Retrieving Individual File Information
To get information on a single file, issue a Get File Info Command (function code 28) to the File
Descriptor Object (obj 70 var 7) specifying a Request ID and the full path file name in the File
Name field as follows
0xC0 28 70 07 0x5B 01 nn nn …(Object…RequestID…”Path\FileName”…Data)
The File Type, File Size, Time of Creation and Permissions fields of the File Descriptor Object in
a request must be ignored by the outstation and must be set to zero by the initiating station.
The device responds with a File Descriptor Object (obj 70 var 7) consisting of the requested
information as follows
0xE0 129 IINs 70 07 0x5B 01 nn nn …(Object…”RequestID…Path\FileName” …Data)
The outstation has requested the host Confirm the response containing an event, so the host
responds as follows
0xC0 00
The end application could display this information in a browser or another appropriate application.
Note: the file shall be fully described, as in:
Path\FileName
If the file referenced does not exist then the outstation should return a File Command Status
Object (obj 70 var 4) with the status field set to File Not Found (0x02).
If the file referenced is a directory file, the File Type field shall be zero to indicate a directory file
and the File Size field shall indicate the number of entries in the sub-directory. To retrieve file
information on all files in a directory, issue a file read on the directory file, as described in section
7.2.
Sequential File Transfer Objects
26 January 2000
DNP Technical Bulletin 2000-001
Page 16
7.2
Retrieving Directory Information
Information can be retrieved for all the files in a directory or sub-directory of a device by
performing a file transfer of the directory file. The directory file shall be read in the manner
described in section 6.4 for sequential file reads. ie. Authenticate (if necessary), Open, Read
blocks up until the end of file, and Close the file.
The outstation responds in the same manner as for any other file read. The format of the
“directory file” transferred from the outstation consists of one or more data objects, one for each
file in the directory, in same format as the File Descriptor Object (obj 70 var 7) i.e. the details
supplied for each file in the directory are:
File Name Offset, File Name Size, File Type, File Size, Time Of Creation, Permissions, Request ID, File Name
The end application may display this information in a browser or another appropriate application.
The file descriptor object data transferred in the directory file read does not include object header
information.
The path to the directory is not contained in each of the individual File Descriptor Object’s File
Name fields. Only the name of the file is included. (The path was specified in the File Command
object used to Open the directory file for read).
The directory file can only be opened for Read.
Retrieving directory information retrieves data for one directory level only. Sub-directories below
the read directory are indicated as files with File Type zero (Directory file), and with the File Size
field indicating the number of entries in the sub-directory. A host wishing to retrieve file
information for all files in a device may perform additional directory file transfers for each subdirectory file.
If the directory referenced does not exist then the outstation should return a File Command
Status Object (obj 70 var 4) with the status field set to File Not Found (0x02).
If the directory exists but contains no files, then the outstation should return a file of zero length
i.e. File Transport Object (obj 70 var 5) is returned with no Data Octets.
7.2.1 Example
Assume that an outstation has the following directory structure
\file0
\dir1
\file1
\file2
\dir2
\file3
\dir3
\file4
If the host reads the root directory file (“\”), it would receive a file with information as follows:
Filename
offset
Filename
size
File
type
File size
Time of creation
Permissions
Request Id
File name
octets
0x14 00
05 00
01 00
nn nn nn nn
nn nn nn nn nn nn
00 00
nn nn
file0
Sequential File Transfer Objects
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DNP Technical Bulletin 2000-001
Page 17
0x14 00
0x14 00
04 00
04 00
00 00
00 00
03 00 00 00
01 00 00 00
nn nn nn nn nn nn
nn nn nn nn nn nn
00 00
00 00
nn nn
nn nn
dir1
dir3
If the host reads the directory file “\dir1”, it would receive a file with information as follows:
Filename
offset
Filename
size
File
type
File size
Time of creation
Permissions
Request Id
File name
octets
0x14 00
0x14 00
0x14 00
05 00
05 00
04 00
01 00
01 00
00 00
nn nn nn nn
nn nn nn nn
01 00 00 00
nn nn nn nn nn nn
nn nn nn nn nn nn
nn nn nn nn nn nn
00 00
00 00
00 00
nn nn
nn nn
nn nn
file1
file2
dir2
8
Minimum Implementation
When a device supports Sequential File Transfer, the following implementation is required as
a minimum. Authentication and Unsolicited Responses are considered optional features of
Sequential File Transfer.
Table 14
Object Variation and Qualifier Codes Required
OBJECT
Obj
Var
70
70
70
70
70
70
2
3
4
5
6
7
Description
REQUEST
RESPONSE
(slave must parse)
(master must parse)
Func
Codes
(dec)
Authentication Object
File Command Object
File Command Status Object
File Transport Object
File Transport Status Object
File Descriptor Object
Qual
Codes
(hex)
25,27
26,30
1,2
0x5B
0x5B
0x5B
28
0x5B
Func
Codes
(dec)
129,130
129,130
129,130
129,130
Qual
Codes
(hex)
0x5B
0x5B
0x5B
0x5B
Affected Documentation:
DNP V3.00 Data Object Library
Chapter 10 File Object Definitions
Changes to the Subset Level 1 and 2 Certification Procedures:
None
Last Updated:
January 26, 2000
Status:
Pending General Membership Approval (Feb 2000)
Sequential File Transfer Objects
26 January 2000
DNP Technical Bulletin 2000-001
Page 18
DNP Technical Bulletin 2000-002
Control Retries
Issue:
This bulletin describes a method of operating controls reliably in the presence of a poor quality
communications network, and adds a new restriction on devices when performing select before operate
controls. This bulletin supercedes Technical Bulletin 9804-001 dated 4/22/98 Item 7 which states "A Host
must never perform application layer retries of output operations, i.e. never send two output messages with
the same sequence number for SELECT, OPERATE, or DIRECT OPERATE function codes."
The requirement as stated above was intended to insure that duplicate controls would not be issued. As
stated the requirement can be misinterpreted to mean that control operations should never be reissued
without operator intervention. It is possible for the Host to safely issue more than one control attempt
without risking duplicate operation. This is desirable in high noise environments to allow the system to
make a “Best Effort Attempt” to operate the control “Exactly Once” without operator intervention.
It is the purpose of this document to describe how more than one control attempt may be performed safely
without risking duplicate control operation while making a “Best Effort Attempt” to operate the control
“Exactly Once” without operator intervention. This is technically not a retry from the protocol’s
perspective, however, it appears as a retry from the operators perspective. Therefore, the remainder of this
document will refer to the Host making more than one control attempt to be a “Control Retry”.
Background:
In a SCADA communications environment all transmissions and receptions are received through the
communications medium, which is often represented as a cloud as shown in Figure 1.
WAN
Host
Outstation
Figure 1
It is possible for messages to get lost in the communications medium as shown in Figure 2
DNP 3 Technical Bulletin 2000-002
Control Retries
Page 1 of 12
January 24, 2000
WAN
Host
Outstation
Figure 2
In this case the Host transmitted a message, the Outstation received it and responded, but the message is
lost in the communications medium. The Host must assume that the Outstation never received the message,
and act accordingly. Technical Bulletin 9804-001 addresses how a Host and Outstation should handle the
various failure scenarios. Technical Bulletin 2000-002 addresses the processing of analog and binary
operations in the various failure scenarios.
Notes:
The following notes apply to the text that follows:
• The term control is used generically to refer to analog and binary outputs. When the type of output is
important, the proper name is used.
• When sequence number is included in the following text it refers to the application sequence number
unless otherwise noted.
• When the term “Retry” appears in the following text it refers to application layer retries unless
otherwise noted.
• When application sequence numbers are incremented they are always incremented modulo 16.
Rules:
1) Technical Bulletin 9804-001 fully applies with the exception of Item 7.
2) The Host may issue multiple retries on the “select” portion of the control dialog.
3) Incrementing the sequence number between retries of the select is at the discretion of the Host.
a) If the Host increments the sequence number between retries, the Outstation will respond to the
select and re-arm the designated point. This also causes the Outstation to re-arm its select-tooperate timers.
b) If the Host retries without incrementing the sequence number, the Outstation will respond to the
select. The original selection will remain unchanged intact., and the Outstation’s select-to-operate
timers will continue running without being reset.
4) The Host must increment the sequence number by exactly one (modulo 16) between the select and
operate command.
5) The Outstation must reject any operate that does not
a) contain a sequence number that is exactly one greater (modulo 16) than the previously accepted
select.
b) match the object portion of the select message byte for byte, excluding the application header.
6) The Host may only issue an operate after successful reception of a select echo from the Outstation.
7) The Host may issue multiple retries on the “operate” portion of control dialog as long as the sequence
number does not change between retries.
8) At no time should the Host retry the select operate sequence in its entirety. Once the select portion has
been satisfied, if the operate portion fails the Host may not retry the select. This can result in duplicate
controls.
9) The Host must never retry direct operate controls. This can result in duplicate controls.
DNP 3 Technical Bulletin 2000-002
Control Retries
Page 2 of 12
January 24, 2000
Scenarios:
The following section presents several scenarios that illustrate the rules stated above.
Scenario 1:
Figure 3 shows a timeline representation of a successful select before operate sequence.
Host
Outstation
Time To
Host Issues Select
SEQ N
Oustation Receives Select
Oustation Echoes Select
Host Receives Echo
SEQ N
Host Sends Operate
SEQ N+1
Outstation Receives Operate
Oustation Operates Control
Oustation Echos Operate
SEQ N+1
Host Receives Echo
Control Dialog Complete
Time Tn
Figure 3
DNP 3 Technical Bulletin 2000-002
Control Retries
Page 3 of 12
January 24, 2000
Scenario 2:
Figure 4 shows a timeline representation of a successful select before operate sequence, where the echo of
the first select is lost and the Host increments the sequence number and retries the select.
Host
Outstation
Time To
Host Issues Select N
SEQ N
Oustation Receives Select N
SEQ N
Oustation Echoes Select
Host Misses Echo N
Host increments sequence
number and retries Select
SEQ N+1
Oustation Receives Select N+1
and resets its operate timer
Oustation Echoes Select N+1
SEQ N+1
Host Receives Echo N+1
Host Sends Operate N+2
SEQ N+2
Outstation Receives Operate N+2
Oustation Operates Control
Oustation Echos Operate N+2
SEQ N+2
Host Receives Echo N+2
Control Dialog Complete
Time Tn
Figure 4
DNP 3 Technical Bulletin 2000-002
Control Retries
Page 4 of 12
January 24, 2000
Scenario 3:
Figure 5 shows a timeline representation of a successful select before operate sequence where the echo of
the first several selects are lost. The Host does not increment the sequence number when retrying the select.
Note: This can cause the operate to be rejected if the select-to-operate timer of the Outstation is configured
to be less than the time it takes to retry the selects.
Host
Outstation
Time To
Host Issues Select
SEQ N
Host Misses Echo N
Oustation Receives Select
SEQ N
Oustation Echoes Select
SEQ N
Oustation Detects Duplicate Sequence Number That
Matches Byte for Byte last message. It Echoes
previous select without processing. Timer is not
reset.
SEQ N
Oustation Detects Duplicate Sequence Number That
Matches Byte for Byte last message. It Echoes
previous select without processing. Timer is not
reset.
Host Retries Select N
SEQ N
Host Misses Echo N
Host Retries Select N
SEQ N
Host Misses Echo N
Host Retries Select N
SEQ N
Host Receives Echo N
SEQ N
Oustation Detects Duplicate Sequence Number That
Matches Byte for Byte last message. It Echoes
previous select without processing. Timer is not
reset.
Host Sends Operate N+1
SEQ N+1
Outstation Receives Operate
Oustation Operates Control
Oustation Echos Operate
SEQ N+1
Host Receives Echo N+1
Control Dialog Complete
Time Tn
Figure 5
DNP 3 Technical Bulletin 2000-002
Control Retries
Page 5 of 12
January 24, 2000
Scenario 4:
Figure 6 shows a timeline representation of a successful select before operate sequence where the echo of
the operate is lost. The Host does not increment the sequence number when retrying the operate.
Host
Outstation
Time To
Host Issues Select N
SEQ N
Host Receives Echo N
Oustation Receives Select
Oustation Echoes Select
SEQ N
Host Sends Operate N+1
SEQ N+1
SEQ N+1
Host Misses Echo N+1
Outstation Receives Operate
Oustation Operates Control
Oustation Echos Operate
Host Retries Operate N+1
SEQ N+1
Host Receives Echo N+1
Control Dialog Complete
SEQ N+1
Oustation Detects Duplicate Sequence Number That
Matches Byte for Byte last message. It Echoes
previous operate without processing.
Time Tn
Figure 6
DNP 3 Technical Bulletin 2000-002
Control Retries
Page 6 of 12
January 24, 2000
Scenario 5:
Figure 7 shows a timeline representation of an invalid select before operate sequence. The echo of the
operate is lost. The Host increments the sequence number when retrying the operate. This results in a false
error.
Host
Outstation
Time To
Host Issues Select N
SEQ N
Host Receives Echo N
Oustation Receives Select
Oustation Echoes Select
SEQ N
Host Sends Operate N+1
SEQ N+1
SEQ N+1
Host Misses Echo N+1
Host Retries Operate N+1
SEQ N+2
Host Receives Echo N+2
and believes the control did
not operate when in fact it
did. Control Dialog Error
SEQ N+2
Outstation Receives Operate
Oustation Operates Control
Oustation Echos Operate
Outstation Detects Operate.
Since the sequence number is not the same as the
previous operate it processes the operate. There was
no select with sequence number N+1 so it echoes
the operate, setting the status field to NO
MATCHING SELECT(status = 2).
Time Tn
Figure 7
DNP 3 Technical Bulletin 2000-002
Control Retries
Page 7 of 12
January 24, 2000
Scenario 6:
Figure 8 shows a timeline representation that illustrates why direct operate controls cannot be retried. In
this example the echo of the direct operate is lost. The Outstation restarts after sending it. The Host retries
the direct operate and the control is eventually operated twice. This cannot occur using select before
operate controls.
Host
Outstation
Time To
Host Issues Direct Operate N
SEQ N
SEQ N
Host Misses Echo N
Host Retries Direct Operate N
Outstation Receives Operate
Oustation Operates Control
Oustation Echos Operate
Outstation Restarts
SEQ N
Outstation is Restarting
SEQ N
Host Misses Echo N
Host Retries Direct Operate N
SEQ N
Outstation is Restarting
SEQ N
Host Misses Echo N
Outstation becomes operational
Host Retries Direct Operate N
SEQ N
Outstation Receives Operate
Oustation Operates Control a second time
Oustation Echos Operate
Host Receives Echo N with
the restart bit set. The control
has already operated a
second time at this point.
This result is unacceptable.
SEQ N
Time Tn
Figure 8
DNP 3 Technical Bulletin 2000-002
Control Retries
Page 8 of 12
January 24, 2000
Affected Documentation:
This document supersedes Technical Bulletin 9804-001 Item 7.
Changes to the Subset Level 1 and 2 Certification Procedures:
Insert additional procedures in binary output section:
Desired Behavior
•
•
•
•
The Outstation must accept retries on the select portion of the control dialog that increment the
application sequence number between retries. In this case the select-to-operate timer must be restarted
after reception of each select.
The Outstation must accept retries on the select portion of the control dialog that do not increment the
application sequence number between retries. In this case the select-to-operate timer must remain
unaltered by the reception of each additional select.
The Outstation must reject any operate that does not
• contain a application layer sequence number that is exactly one greater (modulo 16) than the
previously accepted select.
• match the object portion of the select message byte for byte, excluding the application header.
The Outstation must accept retries on the operate portion of the control dialog that does not increment
the application sequence number between retries. The Outstation must echo the operate command but
must not operate the control more than once.
(Section # TBD) Same Sequence Number Binary Output Select Retries
1.
2.
3.
4.
5.
6.
7.
8.
If the DUT does not have installed binary output points skip this section.
Issue a valid select to an installed binary output point.
Verify that the DUT echoes the object portion of the select byte for byte.
Issue the select again using the same application layer sequence number.
Verify that the DUT echoes the object portion of the select byte for byte.
Issue a valid operate, incrementing the sequence number by 1 modulo 16.
Verify that the DUT echoes the object portion of the operate byte for byte.
Verify that the DUT operates the binary output.
(Section # TBD) Incrementing Sequence Number Binary Output Select Retries
1.
2.
3.
4.
5.
6.
7.
8.
If the DUT does not have installed binary output points skip this section.
Issue a valid select to an installed binary output point.
Verify that the DUT echoes the object portion of the select byte for byte.
Issue the select again incrementing the application layer sequence number by 1 modulo 16.
Verify that the DUT echoes the object portion of the select byte for byte.
Issue a valid operate, incrementing the sequence number by 1 modulo 16.
Verify that the DUT echoes the object portion of the operate byte for byte.
Verify that the DUT operates the binary output.
(Section # TBD) Same Sequence Number Binary Output Operate Retries
1.
2.
3.
4.
5.
6.
7.
8.
If the DUT does not have installed binary output points skip this section.
Issue a valid select to an installed binary output point.
Verify that the DUT echoes the object portion of the select byte for byte.
Issue a valid operate, incrementing the sequence number by 1 modulo 16.
Verify that the DUT echoes the object portion of the operate byte for byte.
Verify that the DUT operates the binary output.
Issue the operate again using the same application layer sequence number.
Verify that the DUT echoes the object portion of the operate byte for byte.
DNP 3 Technical Bulletin 2000-002
Control Retries
Page 9 of 12
January 24, 2000
9.
Verify that the DUT does not operate the binary output.
(Section # TBD) Incrementing Sequence Number Binary Output Operate Retries
1.
2.
3.
4.
5.
6.
7.
8.
9.
If the DUT does not have installed binary output points skip this section.
Issue a valid select to an installed binary output point.
Verify that the DUT echoes the object portion of the select byte for byte.
Issue a valid operate, incrementing the sequence number by 1 modulo 16.
Verify that the DUT echoes the object portion of the operate byte for byte.
Verify that the DUT operates the binary output.
Issue the operate again, incrementing the sequence number by 1 modulo 16.
Verify that the DUT echoes the object portion of the operate byte for byte with a status code value of 2
(NO MATCHING SELECT).
Verify that the DUT does not operate the binary output.
(Section # TBD) Select/Operate Binary Output Sequence number checking
1.
2.
3.
4.
5.
6.
7.
8.
9.
If the DUT does not have installed binary output points skip this section.
Issue a valid select to an installed binary output point.
Verify that the DUT echoes the object portion of the select byte for byte.
Issue a valid operate, incrementing the sequence number by anything but 1 modulo 16.
Verify that the DUT echoes the object portion of the operate byte for byte with a status code value of 2
(NO MATCHING SELECT).
Verify that the DUT does not operate the binary output.
Issue a valid operate, incrementing the select sequence number by 1 modulo 16 to make sure the
mismatched operate cleared the previous select.
Verify that the DUT echoes the object portion of the operate byte for byte with a status code value of 2
(NO MATCHING SELECT).
Verify that the DUT does not operate the binary output.
Insert additional procedures in analog output section:
Desired Behavior
•
•
•
•
The Outstation must accept retries on the select portion of the control dialog that increment the
application sequence number between retries. In this case the select-to-operate timer must be restarted
after reception of each select.
The Outstation must accept retries on the select portion of the control dialog that do not increment the
application sequence number between retries. In this case the select-to-operate timer must remain
unaltered by the reception of each additional select.
The Outstation must reject any operate that does not
• contain a application layer sequence number that is exactly one greater (modulo 16) than the
previously accepted select.
• match the object portion of the select message byte for byte, excluding the application header.
The Outstation must accept retries on the operate portion of the control dialog that does not increment
the application sequence number between retries. The Outstation must echo the operate command but
must not operate the control more than once.
(Section # TBD) Same Sequence Number Analog Output Select Retries
1.
2.
3.
4.
5.
6.
7.
If the DUT does not have installed analog output points skip this section.
Issue a valid select to an installed analog output point.
Verify that the DUT echoes the object portion of the select byte for byte.
Issue the select again using the same application layer sequence number.
Verify that the DUT echoes the object portion of the select byte for byte.
Issue a valid operate, incrementing the sequence number by 1 modulo 16.
Verify that the DUT echoes the object portion of the operate byte for byte.
DNP 3 Technical Bulletin 2000-002
Control Retries
Page 10 of 12
January 24, 2000
8.
Verify that the DUT operates the analog output.
(Section # TBD) Incrementing Sequence Number Analog Output Select Retries
1.
2.
3.
4.
5.
6.
7.
8.
If the DUT does not have installed analog output points skip this section.
Issue a valid select to an installed analog output point.
Verify that the DUT echoes the object portion of the select byte for byte.
Issue the select again incrementing the application layer sequence number by 1 modulo 16.
Verify that the DUT echoes the object portion of the select byte for byte.
Issue a valid operate, incrementing the sequence number by 1 modulo 16.
Verify that the DUT echoes the object portion of the operate byte for byte.
Verify that the DUT operates the analog output.
(Section # TBD) Same Sequence Number Analog Output Operate Retries
1.
2.
3.
4.
5.
6.
7.
8.
9.
If the DUT does not have installed analog output points skip this section.
Issue a valid select to an installed analog output point.
Verify that the DUT echoes the object portion of the select byte for byte.
Issue a valid operate, incrementing the sequence number by 1 modulo 16.
Verify that the DUT echoes the object portion of the operate byte for byte.
Verify that the DUT operates the analog output.
Issue the operate again using the same application layer sequence number.
Verify that the DUT echoes the object portion of the operate byte for byte.
Verify that the DUT does not operate the analog output.
(Section # TBD) Incrementing Sequence Number Analog Output Operate Retries
1.
2.
3.
4.
5.
6.
7.
8.
9.
If the DUT does not have installed analog output points skip this section.
Issue a valid select to an installed analog output point.
Verify that the DUT echoes the object portion of the select byte for byte.
Issue a valid operate, incrementing the sequence number by 1 modulo 16.
Verify that the DUT echoes the object portion of the operate byte for byte.
Verify that the DUT operates the analog output.
Issue the operate again, incrementing the sequence number by 1 modulo 16.
Verify that the DUT echoes the object portion of the operate byte for byte with a status code value of 2
(NO MATCHING SELECT).
Verify that the DUT does not operate the analog output.
(Section # TBD) Select/Operate Analog Output Sequence number checking
1.
2.
3.
4.
5.
6.
7.
8.
9.
If the DUT does not have installed analog output points skip this section.
Issue a valid select to an installed analog output point.
Verify that the DUT echoes the object portion of the select byte for byte.
Issue a valid operate, incrementing the sequence number by anything but 1 modulo 16.
Verify that the DUT echoes the object portion of the operate byte for byte with a status code value of 2
(NO MATCHING SELECT).
Verify that the DUT does not operate the analog output.
Issue a valid operate, incrementing the select sequence number by 1 modulo 16 to make sure the
mismatched operate cleared the previous select.
Verify that the DUT echoes the object portion of the operate byte for byte with a status code value of 2
(NO MATCHING SELECT).
Verify that the DUT does not operate the analog output.
DNP 3 Technical Bulletin 2000-002
Control Retries
Page 11 of 12
January 24, 2000
Last Updated:
January 24, 2000
Status:
Pending General Membership Approval (Feb-2000).
DNP 3 Technical Bulletin 2000-002
Control Retries
Page 12 of 12
January 24, 2000
DNP Technical Bulletin 2000-003
Change Management
Issue:
The use of DNP3 in a wide variety of application areas and communication technologies has led to a need
for periodic revisions and improvements.
In an effort to satisfy the desire for stability yet recognize the need for change, this document outlines the
mechanism that will be employed to manage changes, as they become necessary.
Background:
The DNP Protocol is defined by an extensive documentation set. However, there are areas in the original
documentation, and in subsequent documentation and Technical Bulletins that have
•
•
•
•
•
failed to address areas of inter-operability
provided ambiguous specifications
provided conflicting requirements
provided no guidance
not provided suitable functions, objects or methods for desired commands and data transferal.
It is the responsibility of the technical committee as maintainers of the protocol to address these issues in a
timely manner while providing customers and implementers sufficient time to incorporate changes into
their products and specifications.
Resolution:
When needed the technical committee will issue Technical Bulletins that resolve identified problems and
specify new features. Bulletins fall into four categories
1.
2.
3.
4.
Enhancements or additions to the protocol that no one has implemented before.
Recommendations that are not required for inter-operability and will not be tested for in the
certification procedures.
Rules that are required for inter-operability and will be tested for in the certification
procedures.
Procedural and Organizational rules and requirements (e.g. charter, membership requirements,
certification, etc).
Category 1 and 2 issues do not directly effect existing implementations and may be issued by the technical
committee without requiring General Membership Approval.
Category 3 and 4 issues can potentially affect existing implementations. The Technical Committee will
issue these bulletins with a status indicating “Pending General Membership Approval (Month and Year of
Next Meeting)”.
Each bulletin that specifies desired behavior must also include a certification test section to be included in
the certification test procedures.
Each version of the certification procedures will be denoted by the year the contents were approved by the
General Membership. As an example, the original certification procedures were approved by the General
Membership in February 1999. Devices that passed the tests in those procedures are said to be DNP3-1999
compliant.
DNP 3 Technical Bulletin 2000-003
Change Management
Page 1 of 22
January 26, 2000
Technical Bulletins may be published at any time between General Membership Meetings, however those
that require approval of the General Membership must be published for review not later than thirty days
prior to the General Membership Meeting in which the General Membership will be asked to approve them.
Certification test procedures included in the Technical Bulletins that are approved in a General
Membership Meeting will be incorporated into the certification procedures six months following the
meeting.
Technical Bulletins that are rejected in a General Membership Meeting may be revisited or edited and
resubmitted at the next General Membership meeting.
Six months after the General Membership meeting all previously certified devices must be tested against,
and pass the revised certification procedures in order to be DNP3-xxxx compliant, where xxxx is the year
in which the Technical Bulletins were approved by the general membership. For example, the certification
procedures included in the Technical Bulletins approved in February 2000 would be called DNP3- 2000.
Devices tested during the 6 month grace period between General Membership Approval and the Effective
Date can choose which version of the procedures they wish to be tested against. In the example given
above, devices certified between Feb 2000 and July 2000 could choose to be certified against either the
DNP3-1999 procedures or the DNP3-2000 procedures. Devices certified after July 2000 would be required
to use the DNP3-2000 procedures.
It is recommended that DNP3 users specify which level of compliance they require by specifying which
version of the procedures a device must pass to be purchased. The Technical Committee will maintain a
document on the web site that summarizes the inter-operability issues and enhanced features added for each
version of the certification procedures.
While every attempt is made to insure that two devices that pass the certification procedures inter-operate,
there may be instances in which a behavior has not been specified. In these cases the vendors involved in
the dispute can request arbitration from the technical committee. The Technical Committee will review the
details of the issue and publish a technical bulletin that specifies the correct behavior. This bulletin will by
definition be a category 3 bulletin, and when approved, will be incorporated into the certification
procedures in normal course. Implementers can use the technical bulletin as an advanced notification of
additional requirements that resulted from the arbitration. A fee may be assessed for the arbitration process
at the discretion of the Steering Committee.
Master devices are expected to reliably communicate and inter-operate with certified slave stations. When
they do not, and a compromise solution cannot be reached between the master and slave vendors, the issue
may be submitted to the DNP Technical Committee for arbitration.
Affected Documentation:
None
Changes to the Subset Level 1 and 2 Certification Procedures:
None.
Last Updated:
January 26, 2000
Status:
Pending General Membership Approval (Feb 2000).
DNP 3 Technical Bulletin 2000-003
Change Management
Page 2 of 22
January 26, 2000
DNP Technical Bulletin
Application Layer Confirmation Messages
August 30, 2000
1 Issue
DNP3 protocol defines an application layer message-confirmation service. When used, the receiving application is
required to confirm reception of an application message from the sending application. Confirmation is accomplished
by transmission of a message with the application layer “Confirm” function code, code 0.
The Basic IV is unclear whether or not IIN octets are to be included in application confirm messages sent by the
slave. Section 3.6 of the Application Layer document states that the IIN “… follows the function code in all
responses.” Section 4 contradicts this by explicitly diagramming a Confirmation Response without the IIN.
DNP3 Certification Procedures for Subset Level 1 and Level 2 do not contain any tests for application confirm
messages sent by a slave device in response to a master request.
The DNP Technical Committee has been asked to clarify application confirm requests transmitted by the master and
corresponding application confirm responses transmitted by the slave.
2 Resolution
Since:
• A slave device may pass certification without supporting master application confirm requests, and
• The Basic IV does not clearly define the application confirmation message structure when transmitted by the
slave,
It has been determined that any definition of the structure of a slave application confirm message may result in noncompliance and non-interoperability by some currently certified devices. Furthermore, since there are no meaningful
uses of the application confirmation service when requested by the master, it has been resolved that:
•
•
The master must not transmit any message that requests an application layer confirmation by the slave, and
The slave response to any such request by a non-compliant master is undefined.
3 Last Updated:
30 August 2000
4 Status:
Pending Technical Committee Approval
DNP Technical Bulletin 2000-nnn
Multiple Control Objects
Page 1 of 1
17-August-2000
Last Updated
31 May 2001
Status
Awaiting User Group Comments
14-March-2001
2
TD-Counters-JV-1.doc
DNP Technical Bulletin 2000-005
Reset of User Process Function Code
Issue:
The "Reset of User Process" service function (FC = 1) in the link layer control octet is not defined in the
Basic 4 completely enough to guarantee interoperability. The Data Link Layer document does not define
what action the secondary station should take when it receives the command. Furthermore, the document
does not define what the "user process" of the link layer is or what should be involved in resetting it.
Discussion:
It is undesirable to have the link layer independently "reset" other layers. If the primary station transport
function wants the secondary station transport function to throw away the current fragment it is building
and start a new one, it can simply send a frame having the FIR bit set. Any "restart" or "abort" type
functionality that affects the application layer should be handled by the application layer.
This function code was adopted from the IEC870-5-2 standard, but has not been found to map
appropriately to the DNP3 environment.
Resolution:
DNP3 does not define any action associated with the Data Link Layer Reset User Process request function
code. Support of this function is not required. Function code 1 is now obsolete. This function shall not be
used because there is no definition of the action to be performed by devices that receive this request and
interoperability of devices that use it cannot be guaranteed.
Affected Documentation:
DNP V3.00 Data Link Layer, sections 3.3.3, 3.6.2, 3.7.2
Note: At the time of this bulletin, the Data Link Layer document is undergoing significant revision.
The above resolution will be incorporated into the new version.
DNP3-1999 IED Certification Procedure, Subset Level 1, sections 6, 6.6.2.5
DNP3-1999 IED Certification Procedure, Subset Level 2, sections 6, 6.6.2.5
Changes to the Subset Level 1 and 2 Certification Procedures (v1.00 and v1.01):
6 Link Layer
Replace (i.e. function codes 0, 1, 4, 9) with (i.e. function codes 0, 4, 9).
6.6.2.5 Invalid FCV
Remove 3rd row of table (Code = D1).
Note: These changes have been incorporated into the DNP3-2000 IED Certification Procedures,
Version 2.00.
Last Updated:
November 13, 2000
DNP3 Technical Bulletin 2000-005
Reset of User Process Function Code
Page 1 of 2
November 13, 2000
Status:
Pending General Membership Approval (Feb-2001).
DNP3 Technical Bulletin 2000-005
Reset of User Process Function Code
Page 2 of 2
November 13, 2000
DNP3 Technical Bulletin TB2000-006
Control Relay Output Block (CROB) Control Codes
Issue:
The Control Relay Output Block object provides a great variety of options for performing a control output. The
Technical Bulletin 9701-002 limited the permissible set of functions, but many interoperability problems continue to
arise. While 9701-002 attempted to provide guidance on this issue, it left too much room for misinterpretation.
Without making 9701-002 obsolete, this bulletin clarifies which control codes a device may support on a given
DNP3 index (point), and provides rules that both the master and slave can follow that will guarantee that their use of
the CROB object will interoperate.
Discussion:
The CROB in its current form exposes the details of device hardware to the protocol stack. This is unnecessary and
creates interoperability issues: not all devices support all control codes, and various vendors have chosen
incompatible subsets of control codes to support.
Many master vendors have attempted to achieve interoperability by configuring the control code on a point-by-point
basis. While this works in most cases, some IED vendors have implemented pseudo-points that do different things
based on the control code that is sent. This perverts the original intent of the CROB and makes it impossible for
masters that statically configure control codes to be interoperable with such devices. This type of implementation is
also not transportable across legacy protocol boundaries.
Finally, it makes little sense to support all of the possible combinations of control codes in any case, as most devices
can only support one of two types of control operations on any give DNP3 index:
1. Complementary function (trip/close)
2. Single function (activate)
Resolution:
CROB Index Types:
Each DNP3 Control Relay Output Block index may only support either:
A complementary control function. Examples of complementary control functions are:
• Trip and Close
• Raise and Lower
• On and Off
A single control function. Examples of single-function controls are:
• Trip
• Raise
• Run Battery Test
• Activate
NOTE: Two single-function indices may provide complementary functions. For instance, one index provides the
Trip function while the other provides the Close function. Some indices, such as “Battery Test” may have no
complementary function.
A device may provide some indices that support complementary control functions as well as others that support only
single control functions. An index cannot support both methods of operation.
Control Codes to be Used:
Complementary control function indices may permit one of the complementary control code pairs:
• 0x03 (Latch On/NUL) and 0x04 (Latch Off/NUL)
• 0x41(Pulse On/Close) and 0x81 (Pulse On/Trip)
20-June-2001
1
TB2000-006
Complementary control function indices may permit either or both of these pairs. If an index permits both pairs of
codes, then:
• 0x03 (Latch On/NUL) and 0x41 (Pulse On/Close) must perform the same function
• 0x04 (Latch Off/NUL) and 0x81 (Pulse On/Trip) must perform the same function
Single-function indices may permit one of the following control codes:
•
•
•
•
•
0x01 (Pulse On/NUL)
0x03 (Latch On/NUL)
0x04 (Latch Off/NUL)
0x41 (Pulse On/Close)
0x81 (Pulse On/Trip)
More than one of these codes may be accepted on a given index. However, each of the permitted codes must
perform the same function on that index.
Vendors of slave devices are responsible for assigning control codes that are appropriate to their device. For
example, a manufacturer might assign 0x41 to a breaker and 0x03 to a pseudo point. In DNP3 there is no
significance to these codes providing the above restrictions are met.
A Master device must be configurable to choose, for each index:
• Either one of the complementary control code pairs, or
• Any one of the single control codes.
A vendor must document the control codes its Slave devices support as follows:
• If all indices support the same control codes, the Device Profile Document shall note them.
• If a fixed configuration of differing control codes is used for some or all of the indices, the vendor shall
supply a points list with the Device Profile Document enumerating the codes.
• If the device is configurable per index to support a set of control codes, the Device Profile Document shall
note what the set is.
Affected Documentation:
•
•
•
Basic 4 - Additional Rule
Subset definitions - Additional Rule
Conformance Procedures - Additional Tests
Changes to the Subset Level 1 and 2 Conformance Procedures:
Insert additional procedures in binary output section:
Desired Behavior
•
For complementary function indices, the Outstation must accept at least one of the following control code pairs
• 0x03 (Latch On/NUL) and 0x04 (Latch Off/NUL)
• 0x41 (Pulse On/Close) and 0x81 (Pulse On/Trip).
•
The outstation may optionally accept both forms of complementary control code pairs. If it does:
• control codes 0x03 (Latch On/NUL) and 0x41 (Pulse On/Close) must perform the same function
• control codes 0x04 (Latch Off/NUL) and 0x81 (Pulse On/Trip) must perform the same function
•
For single function indices, the outstation must accept at least one of the following control codes
• 0x01 (Pulse On/NUL)
• 0x03 (Latch On/NUL)
• 0x04 (Latch Off/NUL)
• 0x41 (Pulse On/Close)
• 0x81 (Pulse On/Trip)
20-June-2001
2
TB2000-006
•
If the outstation accepts more than one control code for a single function index, it must perform the same
function for each control code it accepts.
Complementary Function Support
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
14.
15.
16.
17.
18.
19.
20.
21.
If the DUT does not have installed binary output points skip this section.
If the DUT does not have installed complementary function binary output points skip this section.
If the DUT does not support the 0x03 (Latch On/NUL) and 0x04 (Latch Off/NUL) pair skip to step 8
Issue a valid control sequence to the first installed complementary function binary output point using control
code 0x03 (Latch On/NUL).
Verify the control operation completes successfully.
Issue a valid control sequence to an installed complementary function binary output point using control code
0x04 (Latch Off/NUL).
Verify the complementary control operation completes successfully.
If the DUT does not support the 0x41(Pulse On/Close) and 0x81 (Pulse On/Trip) pair skip to step 13
Issue a valid control sequence to an installed complementary function binary output point using control code
0x41(Pulse On/Close).
Verify the control operation completes successfully.
Issue a valid control sequence to an installed complementary function binary output point using control code
0x81 (Pulse On/Trip).
Verify the complementary control operation completes successfully.
If the DUT does not support both the 0x03 (Latch On/NUL) and 0x04 (Latch Off/NUL) control code pair and
the 0x41(Pulse On/Close) and 0x81 (Pulse On/Trip) control code pair skip to step the next section.
Issue a valid control sequence to an installed complementary function binary output point using control code
0x03 (Latch On/NUL).
Verify the control operation completes successfully.
Issue a valid control sequence to the same installed complementary function binary output point using control
0x81 (Pulse On/Trip).
Verify that the complementary control operation completes successfully.
Issue a valid control sequence to the same installed complementary function binary output point using control
code 0x41(Pulse On/Close).
Verify the complementary control operation completes successfully.
Issue a valid control sequence to the same installed complementary function binary output point using control
0x04 (Latch Off/NUL).
Verify the complementary control operation completes successfully.
Single Function Support
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
If the DUT does not have installed binary output points skip this section.
If the DUT does not have installed single function binary output points skip this section.
For any point that is tested below, determine what action should happen when the control executes.
If the DUT does not support the 0x01 (Pulse On/NUL) control code for single function binary output points at
this index skip to step 7.
Issue a valid control sequence to the first installed single function binary output point using control code 0x01
(Pulse On/NUL).
Verify the control operation in step 3 completes successfully.
If the DUT does not support the 0x03 (Latch On/NUL) control code for single function binary output points at
this index skip to step 10.
Issue a valid control sequence to the first installed single function binary output point using control code 0x03
(Latch On/NUL).
Verify the control operation in step 3 completes successfully.
If the DUT does not support the 0x04 (Latch Off/NUL) control code for single function binary output points at
this index skip to step 13.
Issue a valid control sequence to the first installed single function binary output point using control code 0x04
(Latch Off/NUL).
Verify the control operation in step 3 completes successfully.
If the DUT does not support the 0x41 (Pulse On/Close) control code for single function binary output points at
this index skip to step 16.
20-June-2001
3
TB2000-006
14. Issue a valid control sequence to the first installed single function binary output point using control code 0x41
(Pulse On/Close).
15. Verify the control operation in step 3 completes successfully.
16. If the DUT does not support the 0x81 (Pulse On/Trip) control code for single function binary output points at
this index skip to the next section.
17. Issue a valid control sequence to the first installed single function binary output point using control code 0x81
(Pulse On/Trip).
18. Verify the control operation in step 3 completes successfully.
Last Updated:
20-June-2001
Status:
Approved February 5, 2001 by General Membership
20-June-2001
4
TB2000-006
DNP Technical Bulletin 9905-001
Qualifier Code 11 (0x0B)
Issue:
The Basic 4 Application Layer document includes contradictory interpretations of fields
associated with Qualifier Code 11.
The use of Qualifier Code 11 must be clarified to permit consistent implementation of this
feature. It is expected that the use of this qualifier will become more widespread with objects
such as the File Identifier Object (Object 70).
It is also desirable to be able to determine that Qualifier 11 usage correctly follows the
interpretation indicated by this bulletin.
Resolution:
1. Range Field
The Range Field shall always be one octet when using Qualifier Code 11. The content of
this octet specifies the number of objects that follow.
2. Object Size
For each object (as indicated by the count value in the Range Field), the Object Size shall
indicate the number of octets in the following Object Identifier and any following
associated Object Data. By skipping forward this many octets, another Object Size field
(as indicated by the count value in the Range Field), another Object Header or the end of
fragment will be reached.
This allows messages containing objects specified by Qualifier Code 11 to be parsed and
the unrecognized objects ignored if the device does not support these objects.
3. Index Size Codes
Qualifier Code 11 shall use the same definitions of Index Size code as used by all other
Qualifier Codes. Index Size code 5 shall be used to specify the size of the object size
prefix for each object that follows an Object Header using Qualifier Code 11.
The obsolete Index Size codes (those defined for requests using Qualifier Code 11 that
contain no data) shall be removed, leaving a single table of Index Size codes that are
applicable in all situations.
The use of Index Size code 5 with Qualifier Code 11 shall indicate that the Range Field
and Object Size field are to be interpreted as defined by this bulletin.
May 31, 1999
Page 1 of 6 plus Replacement Section 3.7.2
9905-001
Discussion:
This section explains the basis for the analysis and resolution of Qualifier Code 11 issues.
1. Range Field
The size of the Range Field (holding the Count of following objects) is described in
separate places as being:
• Always one octet
• Sized according to the value of the Index Size field
Only one of these interpretations is permissible.
The following sections of the Basic 4 Application Layer document define the use and
structure of object headers that include Qualifier Code 11.
•
Section 3.7.2 describes the Qualifier Codes. In the description of the “Free Format
Qualifier” (Qualifier Code 11) this section states: “The Range Field is always a 1
octet value (Count) which specifies the number of object identifiers.”
•
Section 3.7.3, figures 3-16 and 3-17 show examples for Qualifier Code 11 where the
Range Field (Count of objects) is the same size as the object size field (i.e.: the Range
Field is 1, 2 or 4 octets, for Index Size codes 1, 2 and 3 respectively).
•
Sections 4.2.1, 4.2.2 and 4.3.1 show examples with Qualifier Code 11, Index Size 1
(Index/Qualifier octet value 0x1B). No examples are shown using Index Size codes 2
or 3 (specifying 2- or 4-octet Object Size fields). The associated text could be
interpreted as suggesting either that the Object Count size is always one octet or that
the Index Size sets both Object Count and Object Size to 1 octet.
Currently, for all Qualifier Codes (other than 11), the selection of Qualifier Code value
(alone) determines the form and size of the Range Field (i.e.: the Index Size code does
not affect the form or size of the Range Field). To maintain consistency for all defined
Qualifier Codes (0-9 and 11), the statement in Section 3.7.2 that the Range Field is
always one octet must be observed. Therefore, figures 3-16 and 3-17 are rendered
incorrect by this Technical Bulletin.
For all Qualifier Codes (other than 11), the selection of the Qualifier Code value
explicitly determines the form of the Range Field. If the statement in Section 3.7.2
(Range Field is always one octet) is observed, then the Qualifier Code alone will
determine the size of the Range Field for all defined Qualifier Codes (0-9 and 11). In this
case, the Index Size code only affects the size of each object’s index or object size fields,
and never affects the size of the Range Field. This is a more consistent interpretation than
to assume that figures 3-16 and 3-17 are correct and that the Index Size code also affects
the size of the Range Field.
May 31, 1999
Page 2 of 6 plus Replacement Section 3.7.2
9905-001
2. Object Size
The Object Size field (holding the size in octets of the following object) is described in
separate places as being the size of:
• The object identifier but not the object data
• The object identifier and the object data
Only one of these interpretations is permissible.
The following sections of the Basic 4 Application Layer document the use of the Object
Size field specified in association with Qualifier Code 11.
•
Section 3.7.2 describes the Object Size field as being the size of the object identifier.
It does not make explicit mention of object data: the description only mentions each
object entry as consisting of a size and object identifier pairing.
•
Section 3.7.3, figure 3-16 shows examples for Qualifier Code 11 with the Object Size
being the number of octets in the object identifier. This figure does not include object
data.
•
Section 3.7.3, figure 3-17 shows examples for Qualifier Code 11 where the objects
include data. Here the description explicitly states that the Object Size field is the
count of octets in the object identifier only, and does not include the object data.
•
Section 4.2.1 shows an example for Qualifier Code 11 with the Object Size being the
number of octets in the object identifier. This example does not include object data.
•
Section 4.2.2 shows an example for Qualifier Code 11 where the objects include data.
Here the description explicitly states that the Object Size field is the count of octets in
the object identifier and the object data.
•
Section 4.3.1 shows an example for Qualifier Code 11 where the objects include data.
Here the description explicitly states that the Object Size field is the count of octets in
the object identifier and the object data.
The format of objects specified when using Qualifier Code 11 is a number of consecutive
objects, each of which is preceded by a Size field indicating the size of that object. The
size of each object may be variable, and the inclusion of the size permits each object to be
parsed to its end. Thus a device parsing the object need not provide explicit support for
the object in order to be able to parse to the end of the object(s) and process the
remainder of the message.
If the Object Size field includes the size of the object identifier and any following object
data, it would not be necessary to interpret any part of the object identifier in order to be
able to skip to the next field. It appears that this is the logical purpose for this construct.
Therefore the Size field should include the number of octets in both the object identifier
and the object data.
3. Index Size Codes
The interpretation of Index Size codes for Qualifier Code 11 differ from the interpretation
of Index Size codes for other Qualifier Code values, and the definition of these codes is
May 31, 1999
Page 3 of 6 plus Replacement Section 3.7.2
9905-001
not consistently applied in various sections of the documents. A consistent interpretation
of Index Size values for Qualifier Code 11 is required.
The following sections of the Basic 4 Application Layer document the use of the Index
Size codes (specifically with relation to Qualifier Code 11).
•
Section 3.7.2 defines the Index Size codes. This contains a description specifying a
table of Index Size code values to be used in a Request (with no object data) using
Qualifier Code 11 (codes 1, 2 and 3 only), and a table of values to use in all other
cases.
•
Section 3.7.2 defines Qualifier Code 11. Here it states that Qualifier Code 11 should
be used with Index Size codes 4, 5 or 6 to define the object size.
•
Section 3.7.3, figure 3-16 shows examples of requests or responses without data for
Qualifier Code 11. These examples use Index Size codes 1, 2, and 3.
•
Section 3.7.3, figure 3-17 shows examples of requests or responses with data for
Qualifier Code 11. These examples use Index Size codes 1, 2, and 3.
•
Section 4.2.1 shows an example of a request without data for Qualifier Code 11. This
example uses Index Size code 1.
•
Section 4.2.2 shows an example of a response with data for Qualifier Code 11. This
example uses Index Size Code 1.
•
Section 4.3.1 shows an example of a request with data for Qualifier Code 11. This
example uses Index Size Code 1.
All examples (sections 3.7.3 to 4.3.1) use Index Size codes 1, 2 or 3. This is only
consistent with the Index Size code definition in Section 3.7.2 when used for requests
without data. The definition of Qualifier Code 11 in Section 3.7.2 suggests the use of
Index Size codes 4, 5 and 6 to specify the object size, and does not suggest codes 1, 2 or
3. This is consistent for use of Qualifier Code 11 in responses or in requests that contain
data.
The purpose of Index Size codes 4, 5 and 6 is to specify an object size. This is the same
purpose achieved by Index Size codes 1, 2 and 3 for requests without data using Qualifier
Code 11. Thus the special cases of Index Size codes for requests without data using
Qualifier Code 11 are degenerate forms of codes 4, 5 and 6. The special cases may be
eliminated completely by using Index Size codes 4, 5 and 6 for all cases to specify Object
Sizes.
It is likely that existing implementations using Qualifier Code 11 will have followed the
examples from Sections 3.7.3 to 4.3.1, using Index Size codes 1, 2 or 3, and may have
made either interpretation for size of the Range Field and the content of the Object Size
field. Enforcing the adoption of Index Size codes 4, 5 and 6 in line with their usage for all
other Qualifier Codes will differentiate conformant implementations from nonconformant (or possibly non-conformant) implementations.
Note:
May 31, 1999
To further simplify processing, only Index Size code 5 (specifying a 2-octet size
field) shall be permitted with Qualifier Code 11.
Page 4 of 6 plus Replacement Section 3.7.2
9905-001
Affected Documentation:
Application Layer Section 3.7.3.
Figures 3-16 and 3-17:
Alter the diagrams for Qualifier Code 11:
•
Remove 2nd and 3rd examples
•
Change “Size N1” and “Size NQ” fields to be 16-bit
•
Change “Index Size MUST be 1” to “Index Size code MUST be 5”
Figure 3-17:
Replace the description after “Q-code 11; Index size MUST be 5” with:
Octets Oi1 .. OiN form the object identifier for object i where 0<=i<Q (quantity)
which is followed by the object identified (IDi). The size field Ni contains a count of
the octets in the object identifier (Oi1 .. OiN) and the object identified (IDi). Note
that the Size N+1 field is located Size N octets after the Size N field. Note also that it
is not necessary to be able to interpret the object identifiers or data in order to be able
to process the remainder of the message.
Application Layer Sections 4.2.1, 4.2.2 and 4.3.1:
In all diagrams showing Qualifier Code 11:
Replacing Index Size code 1 with code 5.
In the descriptions that follow diagrams showing Qualifier Code 11:
Replace:
• The qualifier code specifies a list of object identifiers in the identifier field and the
range field is an 8 bit quantity. The size field is also an 8 bit quantity specifying
that the object identifier plus data is ‘size’ octets in length.
• The range field specifies the list contains 1 entry. The index size specifies that the
quantity field and Size field are 8-bit in length.
With:
• The qualifier code 11 specifies a list of object identifiers in the identifier field.
• The index size code of 5 specifies that a 16-bit object size field precedes each
object.
• The range field is an 8-bit quantity specifying the number of object identifiers that
follow.
May 31, 1999
Page 5 of 6 plus Replacement Section 3.7.2
9905-001
Application Layer Sections 4.17, 4.18 and 4.19:
Figures 4-30, 4-32 and 4-34:
In the Qualifier field, replace Index Size code 1 with code 5.
Replace:
• The qualifier indicates the range field is an 8 bit quantity specifying the number of
object identifiers that follow
With:
• The qualifier indicates that the application identifier size field is a 16-bit quantity.
• The range field is an 8-bit quantity specifying the number of object identifiers that
follow.
Application Layer Section 4.20:
Figure 4-36:
In the Qualifier field, replace Index Size code 1 with code 5.
Replace:
• The qualifier indicates the range field is an 8 bit quantity specifying the number of
object identifiers that follow
With:
• The qualifier indicates that the configuration identifier size field is a 16-bit
quantity.
• The range field is an 8-bit quantity specifying the number of object identifiers that
follow.
Application Layer Section 3.7.2:
Replace this section in its entirety with the reworded section appended below:
May 31, 1999
Page 6 of 6 plus Replacement Section 3.7.2
9905-001
3.7.2
Qualifier Field
The qualifier field specifies the meaning of the following Range Field.
bit:
7
R
6
5
4
3
Index Size
2
1
0
4-bit Qualifier Code
Figure 3-15 Qualifier Field
R
Reserved bit always set to 0
The Range Field is used to index data or as an identifier. The structure and use of the
Range Field is dependent on the value in the Qualifier Code field. When the Range Field
is used to index data, it often consists of a Start Range value and a Stop Range value.
Together they define a range of objects in the data following the Object Header. Each of
the Start Range and Stop Range sub-fields is termed as index.
The Range Field may also be a single value, or may be absent if so specified by the
Qualifier Code. A single value may be a count of the objects following the Object
Header, or may specify the index range zero to (range field value – 1).
Table 3-1 lists the commonly-used combinations of Qualifier Code and Index Size Code
(Qualifier Field values), showing the size of the Range Field (in octets).
DNP permits combinations of Qualifier Code and Index Size Code that are not shown in
Table 3-1. These combinations are explained in Figures 3-16 and 3-17. Note that
combinations that do not appear in Table 3-1 are rarely used in DNP implementations,
and only where special conditions warrant their inclusion. It is recommended that only
combinations appearing in Table 3-1 should be used.
Explanations of the purpose of each Qualifier Code and Index Size Code appear
following the tables.
Description
Range Field contains 8 bit start and stop indices
Range Field contains 16 bit start and stop indices
Range Field is omitted, entire range is specified
Range Field contains an 8 bit object count
Range Field contains a 16 bit object count
Free Format Qualifier
Qualifier Field
(hexadecimal)
00
01
06
07, 17
08, 28
5B
Range Size
(octets)
2
4
0
1
2
1
Table 3-1 Commonly-Used Qualifier & Index Codes
3-24
May 31, 1999
9905-001 DNP User Group
Index Size (3-bits)
The 3 bit Index Size field specifies the size of the indices or object size prefixing each
object.
0
1
2
3
4
5
6
7
=
=
=
=
=
=
=
=
objects are packed with no index prefixing them
objects are prefixed with a 1 octet index
objects are prefixed with a 2 octet index
objects are prefixed with a 4 octet index
objects are prefixed with a 1 octet object size
objects are prefixed with a 2 octet object size
objects are prefixed with a 4 octet object size
Reserved
Qualifier Code (4-bits)
The Qualifier Code is used to specify the meaning of the Range Field. Qualifier Code
values are:
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
=
=
=
=
=
=
=
=
=
=
=
=
=
=
=
=
8 bit start and stop indices in the Range Field
16 bit start and stop indices in the Range Field
32 bit start and stop indices in the Range Field
8 bit absolute address identifiers in the Range
16 bit absolute address identifiers in the Range
32 bit absolute address identifiers in the Range
no Range Field (implies all the specified objects)
8 bit single field quantity
16 bit single field quantity
32 bit single field quantity
Reserved
free format qualifier
Reserved
Reserved
Reserved
Reserved
• Start and Stop Sub-Fields in the Range Field (Qualifier Codes 0–5)
The Range Field following the Qualifier field often contains sub-fields (Start
Range and Stop Range) that designate a range of integer values starting
numerically from Start Range (including the number Start Range) to Stop Range
(including the number Stop Range).
For Qualifier Codes 0, 1 and 2, Start Range and Stop Range are interpreted as
indices of data.
For Qualifier Codes 3, 4 and 5, Start Range and Stop Range are interpreted as
virtual memory addresses.
3-25
May 31, 1999
9905-001 DNP User Group
The Qualifier Code can be used both in the request and response messages as it
can uniquely identify data objects whether they do or do not exist in the message.
The Index Size field should be 0 in a data-less message to indicate no further
indexing. The Index Size field can be 4, 5 or 6 in a message with data objects to
indicate that each data object (with indices specified by the Range Field) has an
object size prefix (with this size determined by the Index Size). A message with
data can also use Index Size of 0 to indicate no more indexing. For Qualifier
Codes specifying Start and Stop Indices in the Range, Index Size values of 1, 2
and 3 cannot be used.
• All objects of the given object type (Qualifier Code 6)
When the Qualifier Field equals 6, the length of the Range Field is 0 (i.e. no
Range Field) because all the data objects of the specified type are being referred
to. This qualifier can be used in messages with object headers only because it
cannot uniquely identify data objects if they are present in the message. The Index
Size should be set to 0 when this Qualifier Code is used.
Qualifier Code 6 = no Range Field (implies all the specified objects)
• Single field quantity (Qualifier Codes 7, 8 and 9)
Qualifier Codes 7, 8 and 9 are used to indicate that the Range Field consists of a
single count indicating the number of data objects in question. The Range Field
that follows designates the number of objects referenced.
If the Index Size field equals zero, the Range Field specifies the number of
objects referenced starting numerically from 0 (including 0) to the value in the
Range Field minus 1.
If the Index Size field is 1, 2 or 3 then the Range Field specifies the number of
indices and objects following the Range Field.
Qualifier Codes 7, 8 and 9 can be used in the request and response messages. In a
message with or without data objects, the value in the Range Field specifies the
number of data objects to be referred to. The Index Size field should be set to the
size of the indices that either pre-fix each data object (for messages with data
objects) or that form a sequential list of identifiers.
The Index Size field should not indicate an object size identifier as this would not
uniquely specify the data objects in question and should be set to 0 if no
identifiers or indices are following. The order of identifiers (and optional data
objects) is arbitrary but should not consist of duplicate indices unless specifying
distinct data instances for the same object (e.g.: multiple binary events for a single
binary input).
• Free-format Qualifier (Qualifier Code 11)
3-26
May 31, 1999
9905-001 DNP User Group
This Qualifier Code is used to specify objects when other Qualifier Codes are
inadequate or do not provide enough identifying information.
Qualifier 11 is used only when the Range Field (index) cannot uniquely specify
the data objects in question. In this case, the Qualifier Code defines a variable
length array of octets (string) that contains the object.
This object has a free-format and need not be interpreted in any way by the
application layer.
The Range Field is always a 1-octet value (Count) which specifies the number of
objects. Following the Range Field are Count object size field/object pairs. The
object size field that prefixes each object determines the size of the object (in
octets).
The size of the object size field is determined by the Index Size code. To simplify
processing, only Index Size code 5 is permitted, specifying the size of the object
size field to be 16-bits.
• Reserved Qualifier Codes (Qualifier Codes 10, 12–15)
Qualifier Codes 10 and 12–15 are reserved and should not be used.
3-27
May 31, 1999
9905-001 DNP User Group
This page intentionally blank
3-28
May 31, 1999
9905-001 DNP User Group
DNP Technical Bulletin 9912-002
Unsolicited Event Reporting: Retry Configuration
Note:
This Bulletin identifies a protocol revision approved by the DNP
Technical Committee on December 8, 1999, subject to ratification by
the DNP Users Group.
Issue:
Although DNP provides a method for reporting events through unsolicited
reporting by exception (URBE), successful system deployment requires tuning of
the reporting parameters on a system-by-system basis. This is due to variations in
the performance of communication systems that cannot be universally predicted
during design of a reporting device. For this reason, the Subset Level 2
Certification Procedure requires that a configurable timeout be included in devices
supporting URBE.
Due to the variations in communication system reliability, varying numbers of
retries may be necessary before the URBE is successfully confirmed. In addition,
experience has shown that in systems dictating a very low frequency of integrity
polls, it can take an excessive amount of time to resume normal operation after a
communication interruption. Thus, it is essential to also be able to configure the
retry count such that retries continue on an indefinite basis until communication of
the exception report is successful.
Resolution:
This Bulletin further extends the requirements for configuration of URBE in slave
devices. Devices must support the ability of the end user or system integrator to
choose the maximum number of URBE retry attempts during configuration. One
of the choices must provide for an indefinite (and potentially infinite) number of
retries.
Affected Documentation:
Level 1 and 2 Subset Definitions and Certification Procedures
Modifications to Certification Procedure
Insert additional Procedure:
December 8, 1999
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9912-002.doc
(Section # TBD) Retries unsolicited responses configurable number
of times
1. Configure DUT for a predefined number of retries.
2. Issue a request to enable unsolicited responses for all classes of data by using
function code 0x14 with three object data headers: Object 60, Variation 2;
Object 60, Variation 3; and Object 60, Variation 4.
3. Verify that the DUT responds with a null response indicating the request was
processed without error.
4. Disconnect the communication cable so that confirmations cannot be received
in the slave.
5. Generate class 1, 2, or 3 event data.
6. Verify that an unsolicited response is transmitted. This may involve waiting
for an amount of time, dictated by the DUT and specified by the DUT’s
Device Profile Document, within which the DUT may wait for a minimum
number of events to be collected before transmission of an unsolicited
message.
7. Verify that the unsolicited response requests an application layer confirmation.
8. Verify that DUT retries reporting until number of retries exceeds predefined
number set in (1) above.
9. Repeat procedure, reconnecting communication cable after at least one retry.
Verify that retries are terminated when confirmation is received.
10. Repeat procedure with indefinite retry count configured in DUT.
11. Verify that retries continue for an extended period of time.
December 8, 1999
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9912-002.doc
DNP Technical Bulletin 9912-003
Broadcast Message Confirmation and Address Reservation
Note:
This Bulletin identifies a protocol revision approved by the DNP
Technical Committee on December 8, 1999, subject to ratification by the
DNP Users Group.
Issue:
Broadcast messages serve diverse needs for application functionality as well as
for communication bandwidth optimization. However, these diverse requirements
dictate different processing in response to the broadcast request.
For example, in systems requiring simultaneous freezing of accumulated values
(meter reading, load monitoring, etc.), writing the accumulator freeze application
request to the broadcast address allows this function to be performed in parallel to
multiple devices over communications. Because the delivery of messages to the
broadcast address is not guaranteed, in this application it is essential for the
master to reliably interrogate the IIN1-0 bit (All Stations Message Received) to
know which slaves received the freeze request. The only way to do this is for the
slave to inhibit clearing of IIN1-0 until it knows that the master has received the
message. This is accomplished in DNP by having the slave’s next response
include a confirmation request, and to suppress clearing of the IIN bit until the
confirmation has been received.
In contrast to the first example, consider the case where the message being
broadcast is “Disable Unsolicited Messages” being sent to reduce communication
traffic caused by a major system event. It may not be desirable to generate the
additional communication traffic for subsequent requests particularly when the
receipt of the original broadcast message was intended to reduce bandwidth
usage.
Both of the applications above may coexist in a single network. Thus it is desired
that the confirmation of the receipt of the broadcast message be dynamically
controlled by the master depending upon its requirements.
The DNP specification does not explicitly require or preclude the use of
application layer confirmations to confirm receipt of broadcast messages. Thus
there is a need to further refine the specification to enhance interoperability.
Resolution:
Additional broadcast addresses will be assigned for the purpose of signaling the
slave to request or suppress confirmation of receipt of the broadcast message. The
December 8, 1999
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9912-003.doc
following device addresses are now reserved (Note: All addresses are in
hexadecimal):
FFFF Presently assigned broadcast address. When a message is received on this
address, the slave must set IIN1-0 in the next message it transmits to the
master that sent the broadcast message. The use of this address signifies
that the slave implementation may determine whether or not to request
confirmation of messages sent with IIN1-0 set (that would not otherwise
require confirmation), and whether or not to require the receipt of that
confirmation before clearing IIN1-0 in subsequent messages. This
provides compatibility with existing implementations, and will provide the
same behavior as either one or other of the addresses FFFD and FFFE.
FFFE Messages sent to this address require that the IIN1-0 bit must be returned
with the application layer request for confirmation bit (Application
Control, bit 5) set. IIN1-0 may not be cleared in the slave until the
confirmation is received. Note: If unsolicited event reporting is enabled,
since IIN1-0 may be reported in conjunction with an unsolicited event
report, this response (which requires confirmation) will serve as the
notification that the All Stations message was received.
FFFD Messages sent to this address request the IIN1-0 bit to be returned with the
application layer request for confirmation bit (Application Control, bit 5)
suppressed. IIN1-0 will be cleared in the slave upon transmitting the first
response from the slave. Note: IIN1-0 may be reported in conjunction with
responses to requests that otherwise require confirmation, or with an
unsolicited event report, and since these requests/responses otherwise
require confirmation, the confirmation will not be suppressed even though
the message is sent with IIN1-0 set. Thus the use of the FFFD broadcast
address implies that confirmation requests in responses sent with the IIN10 set should be suppressed, but that the confirmation may be requested if
required by the details of the response being issued.
FFF0–C These addresses are now reserved for future use.
Affected Documentation:
Basic Four Document Set, Level 1 and Level 2 Certification Procedures
Changes to the Subset Level 1 and 2 Certification Procedures
Insert additional Procedure:
(Section # TBD) Broadcast Address Specifying Confirmed
Response Options
1. Cycle the power to the DUT.
2. Issue a request for Object 60 Variation 2.
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3. Verify that the device responds with IIN1-7 set indicating the device has been
restarted.
4. Issue a Write to Object 80 Variation 1 using the qualifier 0x00. Use a start
index of 7 and a stop index of 7, followed by the value 0. Specify broadcast
address FFFE. Request a data link layer confirmation.
5. Wait a reasonable application layer timeout, for example, 2 seconds.
6. Verify that the device does not respond, with either a data link layer
confirmation or a response to the Write operation.
7. Issue a request for Object 60 Variation 2.
8. Verify the DUT responds with a Null Response with IIN1-7 (restart) cleared
and IIN1-0 (all stations message received) set, and an application layer
confirmation requested.
9. Before sending the requested confirmation, repeat the request for Object 60
Variation 2, and verify that IIN1-0 is still set in the response.
10. Send the application layer confirmation.
11. Issue a request for Object 60 Variation 2.
12. Verify the DUT responds with a Null Response with both IIN1-7 and IIN1-1
cleared.
13. Repeat steps 1-12 using address FFFD as the broadcast address. In step 8,
verify that an application layer confirmation is NOT requested. In step 9,
verify that IIN1-0 is not set in the response. Note: Step 10 will not be
necessary.
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DNP V3.00 Technical Bulletin 9804-001
Rules for Synchronizing Application Sequence Numbers
Issue:
The DNP V3.00 Application Layer specification discusses how to use and increment
application layer sequence numbers to detect duplicate messages. However, it does not
specify how these sequence numbers should be initialized or synchronized between two
devices. Because of this, it is possible for a device to erroneously believe it has received a
duplicate message if it or its peer device has recently restarted.
Furthermore, the specification does not discuss how a device receiving a broadcast message
should interpret the sequence number. This is a problem because each device on a broadcast
link may be expecting a different sequence number.
Resolution:
1. The receiver (master or slave) of a broadcast message does not check the sequence number.
Multi-fragment broadcast messages are not permitted.
2. The receiver (master or slave) of a non-broadcast fragment always checks the sequence
number against that of the previous fragment received, except as noted in (5) and (6) below.
3. If the sequence number matches the previous fragment, the receiver compares the incoming
fragment and the previous fragment byte-by-byte. This comparison was not specified in the
original DNP Application Layer description.
4. If both messages match byte-for-byte, then the receiver responds with the same data it sent as
its previous response but does not perform any further action.
5. If a Master is receiving an unsolicited response and the RESTART IIN bit is set, the master
accepts and executes the message regardless of sequence number, then clears the device’s
RESTART IIN. (This need not be a special case, since the RESTART bit will necessarily
make the unsolicited response at least one bit different that the previous one.) It continues
checking sequence numbers thereafter.
6. A device that has just restarted always accepts and executes the first message it receives,
regardless of sequence number. It begins checking sequence numbers thereafter.
7. A Master must never perform application layer retries of output operations, i.e. never send
two output messages with the same sequence number for SELECT, OPERATE, or DIRECT
OPERATE function codes.
Affected Documentation:
DNP V3.00 Application Layer
Chapter 3: Definition of DNP Message Fields
Section 3.2:
Communication Flow Control
Section 3.3:
Master Request & Unsolicited Response Collisions
April 22, 1998
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Technical Bulletin 9804-002
DNP Technical Committee
DNP Confirmation and Retry Guidelines
DNP V3.00 Technical Bulletin 9804-002
DNP Confirmation and Retry Guidelines
1.
Introduction
There has been significant confusion about the usage of Link layer confirmations vs. Application layer
confirmations and when neither, one or both should be used. The general users group membership has
requested that the Technical Committee provide a guideline on this subject. It is the purpose of this
document to review what we are trying to accomplish by the confirmation mechanisms and present a
general guideline for how to use these services effectively.
This guideline supersedes the recommendations presented in the Subset Definitions Revision 2.00 Dated
November 1995.
2.
Background
2.1
Why are confirmations necessary
Certain operations a SCADA (Supervisory Control and Data Acquisition) Remote Electronic Device must
perform require a mechanism to verify that the recipient of a transmission received that transmission
correctly. A classic example is the processing of Status (or Binary Data) changes that have been queued in
the remote device. This data is sometimes referred to as Sequence of Events (SOE) data. The remote
station must insure that the data transmitted to the host remains in order so that a recreation of the real
world “scenario” of status changes can be accomplished by the end user. It must also guarantee that no data
is lost in the transmission process.
In the above example a remote device may have 100 binary changes queued to report to its host. The host
may, however, request that only 20 changes be returned in the current request. The remote device must
have a mechanism for determining when and if the host received the 20 changes so that it can
1. Remove those changes from its change queue
2. Know what to return in the next request
2.2
What are Application Layer Fragments
Each DNP message can consist of one or more application layer “fragments”. Each fragment contains a
whole number of DNP objects, qualifiers, and point indices and is “Parsable” without any additional
assembling of partial messages (otherwise referred to as fragments or packets). In other words, a DNP
application layer is a “Understandable and Fully Digestible” piece of SCADA information.
2.3
What are Application Layer confirmations
A remote device can request that the receiving station (host) send an application layer message in response
to its’ transmission indicating that it received and understood the fragment. Furthermore, the host only
responds to the confirmation request if it can process the message (e.g. it has room in its database for the
information).
April 22, 1998
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Technical Bulletin 9804-002
DNP Technical Committee
DNP Confirmation and Retry Guidelines
2.4
How the Application Layer Confirmation mechanism works
When a remote station transmits vital information (usually event data) that must not be lost and can not be
reproduced (e.g. static data is easily reproduced so it is usually not confirmed) It requests that the host
station send a confirmation message. This confirmation message indicates that the message was received,
understood, and processed (or will be processed) by the host. The remote device has therefore transferred
responsibility for transmission of this data to any subsequent destinations to the host. It can confidently
delete these items from its change buffers.
2.5
What are Link Layer Frames
Each application layer fragment is made up of one or more link layer “frames”. For small messages there
will be one link layer frame for each application fragment. For large messages there will be several link
layer frames for each application layer fragment.
Link frames are not necessarily parsable by themselves. For example, it may take 5 link layer frames
combined together to form a large DNP object that can be parsed by the application Layer.
2.6
What are Link Layer confirmations
When a remote device transmits a link layer frame it can request a link layer confirmation from the host
station. When requested, the host station will transmit a link layer confirm frame to the remote station
indicating that it received that frame and that it was properly formatted.
2.7
How the Link Layer Confirmation mechanism works
In theory a remote station can guarantee delivery of each frame sent to the host station by requesting a link
layer confirmation for each frame. If it receives a confirmation for each and every frame in a transmission
it can be assured that the host accepted the formatting of the frames and that they arrived without any CRC
errors. It cannot, however, determine whether the frames were assembled correctly, or whether the host
understood the objects contained within the assembled application fragment. Only the application layer
confirmation can guarantee this.
2.8
Retransmissions
When the remote device requests either an application layer or a link layer confirmation it waits a specified
period of time before proceeding on to its next task. If the confirmation is not received within this period of
time the request is deemed to have “timed out” and the remote device can either give up for this
transmission or try again, retransmitting the exact same message again. The number of times a device will
try again is set to a relatively low number (usually 3).
Retransmissions can cause synchronization errors in the dialog between the remote device and the host if
one party retransmits and the other was not expecting it. In particular, this can cause collisions in a
Frequently Polled environment.
Retries can be used in some cases, but require careful consideration
• In half-duplex systems, it is possible to configure polling intervals and timeouts large enough to
allow for all possible retries from a device. However this practice sometimes makes polling
intervals larger than desired.
• The use of collision avoidance in the data link and/or physical layers makes retries possible.
• Retries are recommended in the case of unsolicited responses, since collision avoidance is required
as a matter of course. If retries were not employed the master will not be expecting the unsolicited
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Technical Bulletin 9804-002
DNP Technical Committee
DNP Confirmation and Retry Guidelines
data and therefore will not know that it is missing.
It should also be noted that the successful application of retries using collision avoidance techniques
depends on several factors. Among the most important factors include the robustness of the collision
avoidance mechanism employed and the load on the communications channel. If the mechanism is unable
to avoid a collision, retries may aggravate the situation and further reduce effective bandwidth of the
communications channel.
As with any communications system, careful attention must be paid to bandwidth allocation and
management for a successful system design. In particular, overloading communications circuits will have
undesirable effects on system performance. In a frequently polled configuration overloaded circuits will
elongate polling cycles (e.g. scans per second). In an unsolicited response configuration overloaded circuits
will render response times non-deterministic during periods of peak activity.
3.
•
•
•
•
•
Summary
It is recommended that Application layer confirmation be used for binary event data and data link
confirmations be disabled for all data for the following reasons.
1) For most messages Link Layer confirmations are redundant.
2) Link layer confirmations do not insure that the host understands the data sent therefore…
a) Application confirms are required for event data anyway.
1) It only costs 5 bytes of additional overhead to use a more robust confirmation mechanism.
2) There is less ambiguity associated with the sequencing of fragments.
It is recommended that Application Fragment size be reduced as necessary in extremely noisy
environments which will provide similar performance to link layer confirms. This parameter should be
selectable.
NOTE: Due to the requirement that each application fragment be independently parsable, DNP
developers should consider that the application layer fragment cannot be reduced to smaller than the
largest object to be transferred, plus headers and overhead.
It is recommended that retries be disabled in frequently polled environments.
Retries are recommended in unsolicited response configurations, but careful consideration must be
given to communications circuit loading.
These recommendations do not eliminate the requirement for devices to respond correctly to frames
requiring data link confirmation. Devices must respond with CONFIRM - ACK or CONFIRM NACK frames (as specified in the protocol documentation) to any SEND/CONFIRM frames they
receive.
4.
Discussion
4.1
Why Application Layer Confirms are preferred
4.1.1 Link Layer Confirms are Redundant
For most remote station responses that amount of data returned will fit in one link layer frame. This results
in there being one link layer frame for each application layer message. Since we can not determine from a
link layer confirmation whether the host understood our message we need to request an application layer
confirmation for critical data anyway. This makes the link layer confirmation redundant.
April 22, 1998
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Technical Bulletin 9804-002
DNP Technical Committee
DNP Confirmation and Retry Guidelines
It should be noted that almost every Level 1 device (IEDs) returns its’ entire static data set in one
application fragment using only one link layer frame. In fact, at 9600 baud a full link layer message takes
approximately 1/3 of a second to transmit. In a typical Multi-dropped environment where the host will poll
each device for data in a round robin fashion, IEDs returning one full link frame per response would limit
the channel to 6 IEDs per port to maintain the typical 2 second update requirement of most SCADA
systems.
This estimate does not include the time required by the host to transmit the request or the latency in the turn
around time of the remote device or the key-on time of the communications circuit. In the “Real World” a 2
second update can be guaranteed for 3-4 IEDs that return full link layer frames assuming normal latencies.
If you add a link layer confirm to every packet you add at least 10 mS to each exchange between the host
and the remote device, not including device latency or communications latency.
Devices capable of report-by-exception greatly alleviate this problem by transmitting only the data that has
changed since the last request. In the steady state most responses indicate nothing has changed since the
last poll and consume only 17 mS per response. A host can manage (or limit) how much event data the
remote device returns by specifying a maximum number of events to return in the request, thereby
guaranteeing worst case turn around time.
4.1.3 Assures understanding not just reception
Application layer confirmations guarantee that the data transmitted by the remote was assembled and
understood. Link layer confirmations guarantee that the frame arrived with no bit errors. For critical data,
arrival without bit error is not sufficient cause to delete the information from the remote’s change buffers.
Confirmation of proper assembly and understanding of the message are required before a remote can
transfer responsibility of data deliver to the host. Application layer confirmations alone can provide this
information.
4.1.4 Marginal performance penalty
A link layer confirmation requires 10 bytes to transmit. An application layer confirmation requires 17 bytes
to transmit. That is approximately 7 mS at 9600 Baud. It can argued that the latency of device (time
required to begin transmitting) is less for link layer confirms than for application layer confirms. While this
is highly implementation specific and may in some cases be true, the actual latency is often dwarfed by the
turn on time of the transmitter (e.g. radio). In any case, we have shown previously, that for critical data a
link layer confirmation is redundant because an application layer confirmation is required anyway.
4.1.5 Application sequencing is more robust
Link layer frames are much more susceptible to synchronization errors that are Application layer
fragments. Link layer services provide a single bit that toggles for detecting packet ordering. Application
layer services provide an incrementing sequence number for detecting packet ordering. Sequence numbers
are significantly more robust, and less susceptible to synchronization errors.
4.2
Noisy Environments
4.2.1 Smaller packet sizes at higher bit error rates
In high bit error rate (noisy) environments, the probability of an error being introduced into a transmitted
packet increases with the length of the packet. Therefore, the smaller the packet the lower the probability
there will be an error in that packet. When large application layer messages are made up of several link
frames it was intended that each link frame be confirmed individually to minimize the risk of having to resend the entire application layer fragment because one link layer frame was corrupted. Since the
April 22, 1998
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Technical Bulletin 9804-002
DNP Technical Committee
DNP Confirmation and Retry Guidelines
performance penalty for application layer confirms is not significant the same thing can be accomplished
by reducing the application layer fragment size. This has the added benefit of intelligently requesting
confirms as well.
4.2.2 Only Application layer fragment size sets reliability
Typically link layer frame size is not selectable while application layer fragment size is. Since the link
layer frame size is fixed, the probability of error cannot be reduced below Plinkerror where:
Plinkerror = (1 – Pnbitscorrect)
Plinkerror = (1 –(Ponebitcorrect )n )
Plinkerror = (1 - (1 - BER)n )
And
BER = Bit Error Rate
n = 296
Reducing application layer fragments sizewill correspondingly reduce the transmitted link layer frame size
(e.g. reducing n) and realize a reduction of error probability beyond that provided by link services (e.g.
Perror = (1 - (1 - BER)n )).
It should be noted that by reducing application size below link layer size:
• the probability that any one piece of data will make it successfully in high noise environments
is increased.
• the number of turn arounds necessary for large amounts of critical (event) data is increased.
• a practical minimum is no smaller than the largest application object that must be transmitted
plus overhead.
4.3
Retries and Polling
4.3.1 Stepping on your neighbors toes
Application or Link layer retries are not recommended for use in frequently polling environments. If a
remote device requests a confirmation from the host and it does not receive it, the remote device should
wait for the next request to send the information again. If the remote device were to retry it is highly likely
that the host has moved on the next remote device in the polling loop. According to Murphy, that device
will be transmitting its response to the host request when the first device retries and causes a collision.
Even in cases when there is only one device on a line, the device may retry while the host is sending the
next request and cause a collision.
4.3.2 No real benefit
In a polling environment each request can be viewed as an invitation for the remote device to place data on
the share communications circuit. The host acts to manage the bandwidth on the link so the collisions DO
NOT occur, and that the response is predictable under all situations. If any on response is lost, the host will
ask again allowing the remote device to re-send its data. This is effectively a managed retry anyway, but
has eliminated the possibility of collisions.
4.4
Retries and Unsolicited Responses
In a system using unsolicited responses, the physical layers and data link layers of the devices together
manage the bandwidth on the link and avoid collisions. Retries are therefore not a liability in this situation,
April 22, 1998
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Technical Bulletin 9804-002
DNP Technical Committee
DNP Confirmation and Retry Guidelines
because (e.g.collisions) rarely occur. In fact, retries are a requirement when unsolicited responses are
used. Unsolicited data is by definition not expected by the master, and therefore it does not know to
request the data it is missing. The burden is therefore on the remote device to ensure it gets through.
4.5
Unconfirmed User Data Only
Since we are not recommending the use of link layer confirmations, the Frame Control Bit (FCB) and its
associated logic and problems become unnecessary. If you plan never to request a link layer confirm then
there is not need to reset the link, or incorporate the added complexity in the device implementation. Note
however, that all devices must nevertheless respond to RESET LINK and confirmed user data frames with
the appropriate ACK or NACK frames. This is required for interoperability.
5.
Conclusion.
It is the recommendation of the technical committee that link layer confirmation services not be used, but
that unconfirmed user data services be used at the link layer, and that application layer confirmation
services be used exclusively. It is further recommended that in high bit error rate environments (noisy) that
the application fragment size be reduced accordingly. Finally, Application layer or link layer retries should
never be used by a slave device in a frequently polled environment but are acceptable in a unsolicited
response environment assuming adequate collision recovery techniques are used.
Note: Despite the above recommendations certain devices may not be able to receive unconfirmed data link
frames back to back. If a device is capable of generating multiple link layer frames in a single response it is
recommended that it also be able to enable, via configuration, data link confirm requests for flow control.
April 22, 1998
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DNP V3.00 Technical Bulletin 9804-003
Recommended Layer Terminology
Issue:
Some User’s Group members have had difficulty discussing protocol issues because the DNP
documentation does not distinguish well between the sections of DNP messages defined at the Data Link
Layer, Transport Function, and Application Layer.
Resolution:
This bulletin formally distiguishes between an Application Layer fragment, a Transport Function
segment, and a Data Link Layer frame, and clarifies how these terms relate to the Open Systems
Interconnect (OSI) terminology used in much of the Basic 4 documentation.
OSI terminology refers to a Service Data Unit (SDU) and a Protocol Data Unit (PDU). The SDU is the
data presented to the service (upper) interface of a protocol layer by the layer above. The PDU is the data
actually formatted by the layer and passed to the layer below. In the DNP 3-layer model, “PDU” or “SDU”
may be preceded by “Application”, “Transport” or “Link”. Therefore, an APDU is the data transferred
from the application layer to the transport function, and may also be called a TSDU.
The following table defines fragment, segment, and frame and their corresponding OSI terms.
Function
Common
DNP
Name
Fragment
Consists
of...
OSI
Term
Function and Use
Application
Header,
Object
Headers,
Object Data
APDU,
TSDU
Transport
Function
Segment
Transport
Header +
part of an
APDU
TPDU,
LSDU
Data Link
Layer
Frame
Data Link
Header +
CRCs +
complete
TPDU
LPDU
A response to a request may consist of multiple
fragments. Each fragment must be separately
parseable. Fragmentation at the application
layer permits the setting of an upper limit on the
parsing buffer required by the receiving side.
The recommended maximum fragment size is
2K, per the DNP V3.00 Subset Definitions.
Segmentation breaks up a fragment into pieces
that will fit in a Data Link Layer frame. A
segment need not be parseable. Each segment
contains a Transport Header, but only the first
segment of any fragment contains an application
header. A segment consists of up to 250 octets,
249 of which are application layer data.
The data link layer uses a small frame size
relative to the application data to ensure
excellent error detection and recovery. A frame
may be up to 292 octets including all headers
and CRCs.
Application
Layer
Affected Documentation:
DNP V3.00 Transport Functions
Chapter 2
April 22, 1998
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DNP V3.00 Technical Bulletin 9804-004
Virtual Terminal Objects 112 and 113
Issue
DNP 3.0 does not define a protocol suitable for arbitrary, unstructured data flow between Master
and Slave sides of a link. Many IEDs (Intelligent Electronic Devices) have a separate serial
interface used for configuration and diagnostic purposes and directly interfaces with either dumb
terminals or portable computers. The intent of this Virtual Terminal (VT) Protocol is to allow
data transfers which previously required a separate physical connection to a non-DNP port to
proceed over the existing DNP port. Support for VT is optional at the discretion of the IED
vendor.
Resolution
The VT protocol is defined to be the emulation of one or more independent communication links
between the Master and Slave devices which can exchange data. Each Slave communication
channel is assigned a Virtual Port number. These communication links transport proprietary
protocols and are typically used during initial testing and commissioning of a complete system.
The VT proposal is modeled after the TELNET portion of the Internet Protocol Suite.
This Technical Bulletin defines the VT protocol which can be used with DNP 3.0 devices. Two
new DNP objects are defined, along with the procedures for accessing these objects. Both polled
and report-by-exception (RBE) environments are supported. A number of observations are made
regarding this protocol along with recommendations to vendors and integrators concerning
tradeoffs. Finally, rules are defined for VT devices.
Two new objects are defined.
Object 112 is named the “Virtual Terminal Output Block” which is a static object structured
identically to object 110 (Octet String Object). This object is used only with the Function code
WRITE (FC=2) to send data from the Master side to the Slave side of the link.
Object 113 is named the “Virtual Terminal Event Data” which is an event structured identically to
object 111 (Octet String Event Object). This object is used to send data from the Slave side to the
Master side of the link. Master devices may use only Function codes READ (FC=1) or ENABLE
UNSOLICITED MESSAGE (FC=20) or DISABLE UNSOLICIED MESSAGES (FC=21) or
ASSIGN CLASS (FC=22) with this object whereas Slave use only Function codes RESPONSE
(FC=129) or UNSOLICITED MESSAGE (FC=130).
These objects obey the usual DNP rules for static and event objects except that object 112 is
NEVER returned in a Class 0 poll. In particular, object 113 can be assigned to Classes 1-3,
optionally support the assign class function code, and optionally be sent in an unsolicited
response.
The procedure for accessing these objects is as follows. Master devices transmit data to slave
devices by WRITEing one or more of object 112 to a Slave using the Virtual Port number as the
DNP point number. Slaves send information to the Master using the Virtual Port number either
by responding to a Master READ (FC=1) request of object 113 or using an Unsolicited Response
message (FC=130). Messages can flow in either direction at any time. There are no explicit
procedures for the initiation or conclusion of a VT session (i.e. implicit connections exist by the
mere presence of a VT compatible Slave IED).
April 22, 1998
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In the following (hypothetical) example of a VT session, xx/yy is the object number and variation
and all message use point 0:
1. Master:
2. Slave:
3. Master:
4. Slave:
Master)
5. Master:
6. Slave:
7. Master:
8. Master:
9. Master:
10.Slave:
Write 112/1, data=13 decimal= <CR> (our wakeup command)
respond only IIN (FC=129, two IIN bytes)
Read 113/0
respond with IIN only (Slave has no data to send to
Read 113/0
respond with
Write 112/6,
Write 112/7,
Read 113/0
respond with
113/3, data= "OK"<CR>
data= "CLEAR"<CR> (clear slave command)
data= "LOGOFF"<CR> (end the IED session)
113/7, data = "OK"<CR>"BYE"<CR>
(at this point, the Master somehow knows that the Slave will not send additional messages and
therefore it can cease polling the Slave VT port 0)
The above example illustrates a few important points:
Line 4 shows how Slaves respond when no data is available for transmission to the Master
Line 7 and 8 show how a Master could send any number of messages without polling for
responses
Line 10 shows that Slaves MAY accumulate responses (they could also respond with two separate
Messages).
Not shown is that Masters could poll for Slave responses without sending data.
Responsibility for VT maintenance is split between the Master and Slave. The Master is
responsible for maintaining an environment that allows Slaves responses to be sent in a timely
manner. In a polled system, the Master must periodically poll for Slave responses whenever a
response is possible. In an unsolicited response environment, the Master must ensure that the
background data traffic is at a low enough level to ensure that Slave responses can be sent without
impacting more important event data. Slaves are responsible for generation of VT messages
either in response data sent by the Master or spontaneously.
Observations
•
The VT definition allows users to interactively “log onto” an IED without requiring another
serial communication channel beyond the required DNP port. No structure has been defined
for the data passing in either direction. There are two implications of this:
• any octet oriented protocol (including both binary and ASCII) can be sent over VT
• there is no pre-defined "end-of-transmission" indicator.
•
The lack of an "end-of-transmission" indicator implies that Masters must continuously poll
every possible Slave VT port unless responses will never be generated. Three conditions
allow Master to cease polling:
• Slave device is not VT capable
• the system is pre-configured for only unsolicited responses
• (somehow) the Master knows that responses cannot be sent from a VT-capable Slave
•
Since DNP requires point numbers to begin at zero, every VT-capable Slave must support
Virtual Port 0
•
VT traffic will use some DNP bandwidth. There is an implicit assumption made that excess
DNP bandwidth is to be traded for access to other communication channels within the IED.
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If there is no excess bandwidth, using VT to support high-priority IED communications is
pointless.
Recommendations
•
Masters should have some method to attempt retries of data transfer. If a human issues
commands, then this may be as simple as asking the human to repeat the command.
•
Masters should have some means to determine the "end-of-transmission". Again, if a human
issues commands, this could be as simple as forcing the user to "disconnect" from the IED
when finished.
•
If a Slave device has multiple communication ports with different capabilities, Virtual Ports
should also be provided. This allows a one-to-one mapping of physical ports to virtual ports.
Note that additional virtual ports could provide flexibility which does not exist at the physical
connection level.
•
IEDs with large amounts of data transportable over VT should make provisions for limiting
the usage of the DNP link by VT. Possibilities include the ability to disable unsolicited
reporting and allowing configuration of object 113 to Class 1 or Class 2 or Class 3 polls.
•
Limiting the length of the message strings both ensures maximum compatibility with
memory-limited devices and allows other higher priority messages to be interspersed with VT
messages. Note that a single data link fame accommodates up to a 240 octets VT message.
Rules
•
•
•
Object 112 is used only with the WRITE function code from the Master. Reads are not
allowed.
The point number(s) to be used for VT must appear in the Device Profile Document.
Slaves which support VT must support the Response function code (FC=129). They may
optionally support Unsolicited Response and Assign Class functions.
Affected Documents
DNP 3.0 Data Object Library
Chapter 14: New chapter name to be determined.
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DNP Technical Bulletin 9804-005
8-Bit Unsigned Integer Object 102
Issue:
Some devices require the capability to read and write single-byte values, for which the
existing analog input and output values are insufficient.
Resolution:
A new object, Object 102, is defined as an 8-bit Unsigned Integer Object
Reading and Writing of 8 bit memory locations could be implemented using this object
together with absolute addressing qualifiers.
Please refer to the following Object Definition for Details.
Affected Documentation:
DNP V3.00 Object Library
Chapter 13:
Alternate Numeric Object Definitions
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8-Bit Unsigned Integer Object
Data Object 102 Variation 1
Type: Static
Description:
The 8-Bit Unsigned Integer Object represents a value from 0 to 255. This object is not
included in Class 0 poll response. For this object only read, write and response function
codes are permitted.
Object Coding:
Current Value [0]
7
0
UI1 = SQ1 { Current Value = UI [0..7] <0..255>}
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DNP Technical Bulletin 9804-006
Analog Object Floating Point Variations
Issue:
The DNP User’s Group required a definition for a standard implementation of Floating
Point Objects and Floating Point Event Objects. These are required for representation of
analog quantities in floating point format.
Resolution:
Floating Point Object reporting is defined as follows:
•
•
•
•
•
•
The existing object group 100 is not designated “Static”. To read a group 100
value, it is necessary to specifically request that group.
It is recommended that existing group 100 objects not be used in the future.
Short and Long Floating point variations have been added to object groups
30, 31, 32, 33, 40 and 41. Note that this includes floating point outputs as
well as static, frozen and event floating point inputs. Events can be reported
with or without timestamps. Attached Object Definitions specify details.
These variations shall not be part of any current subset definition.
If a device supports these floating point variations, it must provide a
configuration mechanism that will force these points to be reported as
integers when polled for Class Data or variation zero (0). It is appropriate for
the device to set the over-range flag if necessary due to conversion problems.
When not configured to force reporting as integer, a remote device may
default to responding to a request for Class Data or variation zero (0) by
reporting some data as integer and some data as floating point.
Note:
•
•
The extended format used in Object 100 Variation 3 has not included.
The floating point variations of objects 30, 31, 32, 33, 40 and 41 do not
include the Units field used in Object 100. An alternate mechanism for
providing this information may be provided in the future.
Affected Documentation:
DNP V3.00 Data Object Library
Chapter 6 Analog Input Object Definitions
Chapter 7 Analog Output Object Definitions
Chapter 13 Alternate Numeric Object Definitions
April 22, 1998
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SHORT FLOATING POINT ANALOG INPUT
Data Object 30 - Variation: 05
Type: Static
Description:
The Short Floating Point Analog Input information object represents a
hardware or software analog point. The format of this object complies
with the IEEE-754 standard for floating-point number representation.
The value field holds the current floating point value of the analog input at
the time of reporting or the last reported value from the originating device,
and follows the format for a short real as specified by the IEEE-754
standard.
The flag field holds information about the point and has the same meaning
as previous objects with the following additions:
The over-range field indicates that the analog signal is out of range for the
A to D converter to process.
The reference check field indicates that the reference signal used to
digitize the analog input is not stable and the resulting digitized value
may not be correct.
Object Coding:
Flag
7
0
Value
S Exponent
0 7
0
Mantissa
22
0
*S = Sign
SQ2 { Flag
Value
=
=
BS8 [0..7]
R32 { Sign = BS1 [0] <0, positive; 1, negative>
Exponent = UI8 [0..7] <0..255>
Mantissa = UI23 [0..22] <0..223-1>
}
}
April 22, 1998
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Narrative:
The absolute value can be derived from the value field as follows:
April 22, 1998
Absolute_Value
=
1.s22 s21 s20 s19 s18 .. s0 x 2 (Exp -127)
where:
and
si
Exp
=
=
Mantissa[0..22]
Exponent[0..7]
Sign:
Exponent:
Mantissa:
0 if number is positive, and 1 if the number is negative.
Power of 2 applied to (1.Mantissa).
Binary digits in value following the binary point.
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LONG FLOATING POINT ANALOG INPUT
Data Object 30 - Variation: 06
Type: Static
Description:
The Long Floating Point Analog Input information object represents a
hardware or software analog point. The format of this object complies
with the IEEE-754 standard for floating-point number representation.
The value field holds the current floating point value of the analog input at
the time of reporting or the last reported value from the originating device,
and follows the format for a long real as specified by the IEEE-754
standard.
The flag field has the same meaning as the flag field of Object 30
Variation 5.
Object Coding:
Flag
7
0
Value
S Exponent
0 10
0
Mantissa
51
0
*S = Sign
SQ2 { Flag
Value
=
=
BS8 [0..7]
R64 { Sign = BS1 [0] <0, positive; 1, negative>
Exponent = UI8 [0..10] <0..2047>
Mantissa = UI23 [0..51] <0..252-1>
}
}
April 22, 1998
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Narrative:
The absolute value can be derived from the value field as follows:
April 22, 1998
Absolute_Value
=
1.s51 s50 s49 s48 s47 .. s0 x 2 (Exp -1023)
where:
si
Exp
=
=
Mantissa[0..51] and
Exponent[0..10]
Sign:
Exponent:
Mantissa:
0 if number is positive, and 1 if the number is negative.
Power of 2 applied to (1.Mantissa).
Binary digits in value following the binary point.
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SHORT FLOATING POINT FROZEN ANALOG INPUT
Data Object 31 - Variation: 07
Type: Frozen Static
Description:
The Short Floating Point Frozen Analog Input information object
represents a frozen hardware or software analog point. The format of this
object complies with the IEEE-754 standard for floating-point number
representation.
The frozen value field holds the floating point value of the analog input at
the time of the last Freeze command was completed on this point, and
follows the format for a short real as specified by the IEEE-754 standard.
This field is as described for the value field of Object 30 Variation 5.
The flag field has the same meaning as the flag field of Object 30
Variation 5.
Object Coding:
Flag
7
0
S Exponent
0 7
0
Frozen Value
Mantissa
22
0
*S = Sign
SQ2 { Flag
Value
=
=
BS8 [0..7]
R32 { Sign = BS1 [0] <0, positive; 1, negative>
Exponent = UI8 [0..7] <0..255>
Mantissa = UI23 [0..22] <0..223-1>
}
}
April 22, 1998
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LONG FLOATING POINT FROZEN ANALOG INPUT
Data Object 31 - Variation: 08
Type: Frozen Static
Description:
The Long Floating Point Frozen Analog Input information object
represents a frozen hardware or software analog point. The format of this
object complies with the IEEE-754 standard for floating-point number
representation.
The frozen value field holds the floating point value of the analog input at
the time of the last Freeze command was completed on this point, and
follows the format for a long real as specified by the IEEE-754 standard.
This field is as described for the value field of Object 30 Variation 6.
The flag field has the same meaning as the flag field of Object 30
Variation 5.
Object Coding:
Flag
7
0
S Exponent
0 10
0
Frozen Value
Mantissa
51
0
*S = Sign
SQ2 { Flag
Value
=
=
BS8 [0..7]
R64 { Sign = BS1 [0] <0, positive; 1, negative>
Exponent = UI8 [0..10] <0..2047>
Mantissa = UI23 [0..51] <0..252-1>
}
}
April 22, 1998
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SHORT FLOATING POINT ANALOG CHANGE EVENT
Data Object 32 - Variation: 05
Type: Event
Description:
The Short Floating Point Analog Change Event information object
represents a changed hardware or software analog point. The format of
this object complies with the IEEE-754 standard for floating-point number
representation.
The value field holds the current floating point value of the analog input at
the time of reporting or the last reported value from the originating device,
and follows the format for a short real as specified by the IEEE-754
standard. This object is only reported when an event occurs such as a
deadband excursion. This field is as described for the value field of Object
30 Variation 5.
The flag field has the same meaning as the flag field of Object 30
Variation 5.
Object Coding:
Flag
7
0
Value
S Exponent
0 7
0
Mantissa
22
0
*S = Sign
SQ2 { Flag
Value
=
=
BS8 [0..7]
R32 { Sign = BS1 [0] <0, positive; 1, negative>
Exponent = UI8 [0..7] <0..255>
Mantissa = UI23 [0..22] <0..223-1>}
}
April 22, 1998
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LONG FLOATING POINT ANALOG CHANGE EVENT
Data Object 32 - Variation: 06
Type: Event
Description:
The Long Floating Point Analog Change Event information object
represents a changed hardware or software analog point. The format of
this object complies with the IEEE-754 standard for floating-point number
representation.
The value field holds the current floating point value of the analog input at
the time of reporting or the last reported value from the originating device,
and follows the format for a long real as specified by the IEEE-754
standard. This object is only reported when an event occurs such as a
deadband excursion. This field is as described for the value field of Object
30 Variation 6.
The flag field has the same meaning as the flag field of Object 30
Variation 5.
Object Coding:
Flag
7
0
Value
S Exponent
0 10
0
Mantissa
51
0
*S = Sign
SQ2 { Flag
Value
=
=
BS8 [0..7]
R64 { Sign = BS1 [0] <0, positive; 1, negative>
Exponent = UI8 [0..10] <0..2047>
Mantissa = UI23 [0..51] <0..252-1>}
}
April 22, 1998
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SHORT FLOATING POINT ANALOG CHANGE EVENT WITH TIME
Data Object 32 - Variation: 07
Type: Event
Description:
The Short Floating Point Analog Change Event information object
represents a changed hardware or software analog point. The format of
this object complies with the IEEE-754 standard for floating-point number
representation.
The value field holds the current floating point value of the analog input at
the time of reporting or the last reported value from the originating device,
and follows the format for a short real as specified by the IEEE-754
standard. This object is only reported when an event occurs such as a
deadband excursion. This field is as described for the value field of Object
30 Variation 5.
The time field shows the time at which the processing caused the event.
The flag field has the same meaning as the flag field of Object 30
Variation 5.
Object Coding:
Flag
7
0
Value
S Exponent
0 7
0
Mantissa
22
Time
48
0
0
*S = Sign
SQ3 { Flag
Value
=
=
Time
=
BS8 [0..7]
R32 { Sign = BS1 [0] <0, positive; 1, negative>
Exponent = UI8 [0..7] <0..255>
Mantissa = UI23 [0..22] <0..223-1>}
UI48 [0.47] <0.. 248-1>
}
April 22, 1998
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LONG FLOATING POINT ANALOG CHANGE EVENT WITH TIME
Data Object 32 - Variation: 08
Type: Event
Description:
The Long Floating Point Analog Change Event information object
represents a changed hardware or software analog point. The format of
this object complies with the IEEE-754 standard for floating-point number
representation.
The value field holds the current floating point value of the analog input at
the time of reporting or the last reported value from the originating device,
and follows the format for a long real as specified by the IEEE-754
standard. This object is only reported when an event occurs such as a
deadband excursion. This field is as described for the value field of Object
30 Variation 6.
The time field shows the time at which the processing caused the event.
The flag field has the same meaning as the flag field of Object 30
Variation 5.
Object Coding:
Flag
7
0
Value
S Exponent
0 10
0
Mantissa
51
Time
48
0
0
*S = Sign
SQ3 { Flag
Value
=
=
Time
=
BS8 [0..7]
R64 { Sign = BS1 [0] <0, positive; 1, negative>
Exponent = UI8 [0..10] <0..2047>
Mantissa = UI23 [0..51] <0..252-1>}
UI48 [0.47] <0.. 248-1>
}
April 22, 1998
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SHORT FLOATING POINT FROZEN ANALOG EVENT
Data Object 33 - Variation: 05
Type: Frozen Event
Description:
The Short Floating Point Frozen Analog Event information object
represents a frozen hardware or software analog point that is reported as
an event. The format of this object complies with the IEEE-754 standard
for floating-point number representation.
The frozen value field holds the floating point value of the analog input at
the time of the last Freeze command was completed on this point, and
follows the format for a short real as specified by the IEEE-754 standard.
This field is as described for the value field of Object 30 Variation 5.
The flag field has the same meaning as the flag field of Object 30
Variation 5.
Object Coding:
Flag
7
0
S Exponent
0 7
0
Frozen Value
Mantissa
22
0
*S = Sign
SQ2 { Flag
Value
=
=
BS8 [0..7]
R32 { Sign = BS1 [0] <0, positive; 1, negative>
Exponent = UI8 [0..7] <0..255>
Mantissa = UI23 [0..22] <0..223-1>}
}
April 22, 1998
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LONG FLOATING POINT FROZEN ANALOG EVENT
Data Object 33 - Variation: 06
Type: Frozen Event
Description:
The Long Floating Point Frozen Analog Event information object
represents a frozen hardware or software analog point that is reported as
an event. The format of this object complies with the IEEE-754 standard
for floating-point number representation.
The frozen value field holds the floating point value of the analog input at
the time of the last Freeze command was completed on this point, and
follows the format for a long real as specified by the IEEE-754 standard.
This field is as described for the value field of Object 30 Variation 6.
The flag field has the same meaning as the flag field of Object 30
Variation 5.
Object Coding:
Flag
7
0
S Exponent
0 10
0
Frozen Value
Mantissa
51
0
*S = Sign
SQ2 { Flag
Value
=
=
BS8 [0..7]
R64 { Sign = BS1 [0] <0, positive; 1, negative>
Exponent = UI8 [0..10] <0..2047>
Mantissa = UI23 [0..51] <0..252-1>}
}
April 22, 1998
13 of 199
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SHORT FLOATING POINT FROZEN ANALOG EVENT WITH TIME
Data Object 33 - Variation: 07
Type: Frozen Event
Description:
The Short Floating Point Frozen Analog Event information object
represents a frozen hardware or software analog point that is reported as
an event. The format of this object complies with the IEEE-754 standard
for floating-point number representation.
The frozen value field holds the floating point value of the analog input at
the time of the last Freeze command was completed on this point, and
follows the format for a short real as specified by the IEEE-754 standard.
This field is as described for the value field of Object 30 Variation 5.
The time field shows the time at which the processing caused the event.
The flag field has the same meaning as the flag field of Object 30
Variation 5.
Object Coding:
Flag
7
0
S Exponent
0 7
0
Frozen Value
Mantissa
22
Time
48
0
0
*S = Sign
SQ3 { Flag
Value
=
=
Time
=
BS8 [0..7]
R32 { Sign = BS1 [0] <0, positive; 1, negative>
Exponent = UI8 [0..7] <0..255>
Mantissa = UI23 [0..22] <0..223-1>}
UI48 [0.47] <0.. 248-1>
}
April 22, 1998
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LONG FLOATING POINT FROZEN ANALOG EVENT WITH TIME
Data Object 33 - Variation: 08
Type: Frozen Event
Description:
The Long Floating Point Frozen Analog Event information object
represents a frozen hardware or software analog point that is reported as
an event. The format of this object complies with the IEEE-754 standard
for floating-point number representation.
The frozen value field holds the floating point value of the analog input at
the time of the last Freeze command was completed on this point, and
follows the format for a long real as specified by the IEEE-754 standard.
This field is as described for the value field of Object 30 Variation 6.
The time field shows the time at which the processing caused the event.
The flag field has the same meaning as the flag field of Object 30
Variation 5.
Object Coding:
Flag
7
0
S Exponent
0 10
0
Frozen Value
Mantissa
51
Time
48
0
0
*S = Sign
SQ3 { Flag
Value
=
=
Time
=
BS8 [0..7]
R64 { Sign = BS1 [0] <0, positive; 1, negative>
Exponent = UI8 [0..10] <0..2047>
Mantissa = UI23 [0..51] <0..252-1>}
UI48 [0.47] <0.. 248-1>
}
April 22, 1998
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SHORT FLOATING POINT ANALOG OUTPUT STATUS
Data Object 40 - Variation: 03
Type: Static
Description:
The Short Floating Point Analog Output Status information object
represents the actual value of an analog output or software point and
associated status. The format of this object complies with the IEEE-754
standard for floating-point number representation.
The value field holds the current floating point value of the analog output,
and follows the format for a short real as specified by the IEEE-754
standard. This field is as described for the value field of Object 30
Variation 5.
The flag field holds information about the point and has the same meaning
as previous objects.
Object Coding:
Flag
7
0
Value
S Exponent
0 7
0
Mantissa
22
0
*S = Sign
SQ2 { Flag
Value
=
=
BS8 [0..7]
R32 { Sign = BS1 [0] <0, positive; 1, negative>
Exponent = UI8 [0..7] <0..255>
Mantissa = UI23 [0..22] <0..223-1>}
}
Narrative:
This object can be returned after an analog output block operation is
performed to determine the success of the operation.
April 22, 1998
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LONG FLOATING POINT ANALOG OUTPUT STATUS
Data Object 40 - Variation: 04
Type: Static
Description:
The Long Floating Point Analog Output Status information object
represents the actual value of a hardware or software analog output point.
The format of this object complies with the IEEE-754 standard for
floating-point number representation.
The value field holds the current floating point value of the analog output,
and follows the format for a long real as specified by the IEEE-754
standard. This field is as described for the value field of Object 30
Variation 6.
The flag field holds information about the point and has the same meaning
as previous objects.
Object Coding:
Flag
7
0
Value
S Exponent
0 10
0
Mantissa
51
0
*S = Sign
SQ2 { Flag
Value
=
=
BS8 [0..7]
R64 { Sign = BS1 [0] <0, positive; 1, negative>
Exponent = UI8 [0..10] <0..2047>
Mantissa = UI23 [0..51] <0..252-1>}
}
Narrative:
This object can be returned after an analog output block operation is
performed to determine the success of the operation.
April 22, 1998
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SHORT FLOATING POINT ANALOG OUTPUT BLOCK
Data Object 41 - Variation: 03
Type: Static
Description:
The Short Floating Point Analog Output Block information object
represents the desired value of a hardware or software analog output point.
The format of this object complies with the IEEE-754 standard for
floating-point number representation.
The requested value field holds the desired floating point value of the
analog output, and follows the format for a short real as specified by the
IEEE-754 standard. The actual value is returned in the analog output
status object. This field is as described for the value field of Object 30
Variation 5.
The control status field indicates the status of the analog control operation
in the same way as the control relay output block. The definition of this
field is the same as the control relay output block.
Object Coding:
Requested Value
S Exponent
Mantissa
0 7
0
22
Control
Status
7
0
0
*S = Sign
SQ2 { Value
=
Ctrl Stat =
R32 { Sign = BS1 [0] <0, positive; 1, negative>
Exponent = UI8 [0..7] <0..255>
Mantissa = UI23 [0..22] <0..223-1>}
BS8 [0..7]
}
April 22, 1998
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LONG FLOATING POINT ANALOG OUTPUT BLOCK
Data Object 41 - Variation: 04
Type: Static
Description:
The Long Floating Point Analog Output Block information object
represents the desired value of a hardware or software analog output point.
The format of this object complies with the IEEE-754 standard for
floating-point number representation.
The requested value field holds the desired floating point value of the
analog output, and follows the format for a long real as specified by the
IEEE-754 standard. The actual value is returned in the analog output
status object. This field is as described for the value field of Object 30
Variation 6.
The status field indicates the status of the analog control operation in the
same way as the control relay output block. The definition of this field is
the same as the control relay output block.
Object Coding:
Requested Value
S Exponent
Mantissa
0 10
0
51
Control
Status
7
0
0
*S = Sign
SQ2 { Value
=
Ctrl Stat =
R64 { Sign = BS1 [0] <0, positive; 1, negative>
Exponent = UI8 [0..10] <0..2047>
Mantissa = UI23 [0..51] <0..252-1>}
BS8 [0..7]
}
April 22, 1998
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DNP V3.00 Technical Bulletin 9804-007
Clarification of Collision Avoidance Procedures
Issue:
The DNP V3.00 Data Link Layer specification, Chapter 7: Physical Procedures, discusses
many different issues and configurations of physical connections in a general manner.
Unfortunately, it does not clearly describe how to avoid collisions between messages,
especially unsolicited messages, sent by several devices sharing a half-duplex, multi-drop
link. This bulletin is intended to provide that description.
Resolution:
The physical layer must provide an indication to the data link layer of when the link is in use,
e.g. using the DCD (Data Carrier Detect) signal.
If a device prepares to transmit and finds the link busy, it waits until it is no longer busy, then
waits a backoff_time as follows:
backoff_time = fixed_delay + random( max_random_delay )
After the backoff_time, the device tries again, either indefinitely, or up to a configurable
maximum number of retries. If a maximum is used, the protocol behaves as if a link failure
occurred, i.e. data is returned to buffers at the application layer and application layer retries
take place if desired.
The fixed_delay can be adjusted per device to provide priority of access. For instance, it
could be zero (0) for masters and non-zero for all the slave devices. This provides a minimum
"window" of access time for the master(s).
Affected Documentation:
DNP V3.00 Data Link Layer
Chapter 7: Physical Procedures
April 22, 1998
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DNP Technical Bulletin 9804-008
Unissued Object and Variation Numbers
Issue:
It has been noted that some vendors have assigned as-yet-unallocated DNP Object and
Variation numbers to private objects. This allocation can lead to incompatible extensions to
the protocol. Guidelines regarding this practice are required.
Resolution:
The DNP User Group advises that:
•
DNP must not be used to transport objects other than those already published by the
DNP User Group in the DNP Protocol Specification documents or in DNP Technical
Bulletins.
•
Proposals for extensions to the protocol can be presented for consideration by the
User Group’s Technical Committee, and will be included in the protocol if
considered appropriate. The Technical Committee may alter any proposed object or
variation numbering in accordance with established guidelines, and may also revise
other details of the proposal to ensure compatibility with other aspects of the
protocol. Proposals should be submitted to the Secretary of the DNP User Group,
together with relevant supporting documentation describing the proposed new object
or variation and its purpose.
•
Note that it is extremely rare for the Technical Committee to introduce new features
to the protocol that are not completely backward-compatible with the existing
published protocol definition. From time to time the Technical Committee may issue
advisory bulletins that clarify the protocol definition, or make recommendations on
aspects of protocol implementation.
•
Implementors should note that the Private Registration Object (Object 83) permits the
definition of vendor-specific data objects. This object may be used for adding
proprietary features to devices that communicate using DNP.
Affected Documentation:
Nil.
April 22, 1998
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9804-008.doc
DNP Technical Bulletin 9809-001
Analog Input Reporting Deadband
Issue:
There is perceived to be a need for a mechanism to permit the master station to retrieve and set
the reporting deadband parameter for analog inputs.
Explanatory Notes:
The analog input reporting deadband is normally used in one of two ways depending on
the capabilities and configuration of the reporting equipment:
•
Fixed Deadband. If the absolute value of the difference between the last-reported
value of an analog input object and the current value of that object exceeds the
deadband value, then an event is generated for that object with the current value sent
as the value for the event.
•
Integrating Deadband. While the value of an analog input object differs from the
last-reported value for that object, the difference is integrated over time. When the
integral of the difference exceeds the deadband, then an event is generated for that
object with the current value sent as the value for the event.
It is assumed that only one of these two mechanisms is being used. This means that a
single deadband value is assigned for each analog input point, not two separate values (a
fixed deadband value and an integrating deadband value) assigned for each point.
Resolution:
The DNP Technical Committee has allocated Object 34 as the means of reporting or
setting the reporting deadband value of an Analog Input. This object will support the
Read and Write functions. It will not be reported in response to Read requests for Class 0
Data (that is: It will only be returned in response to a Read command that specifically
requests Object 34). The master may alter the value of an analog input’s deadband by
issuing a Write command containing the Analog Input Reporting Deadband Object.
Object 34 has no flags. The indices assigned to Object 34 parallel those assigned to
Object 30. This means that the reporting deadband for Object 30 Index n is Object 34
Index n, events on this point are reported as Object 32 index n.
Three variations of Object 34 are defined: 16-bit and 32-bit integer formats and a
floating-point format. Systems that only report analog events using integer formats
(Object 32 Variations 1–4) should use the integer variations of Object 34 (Variations 1
and 2). Systems that can report analog events using floating-point formats (Object 32
Variation 5–8) may use either the floating-point variation of Object 34 (Variation 3) or
the integer variations (Variations 1 and 2), and must perform conversion between integer
and floating-point formats as required by DNP Technical Bulletin 9804-006. It is
recommended that for each individual point, the same format (integer or floating-point as
required) be used with Objects 30, 32 and 34.
Object 34 may be used for setting or reporting either a Fixed Deadband value or an
Integrating Deadband value. For a fixed deadband, the value set will be the absolute
September 10, 1998
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9809-001.doc
difference value in Counts (Variations 1 and 2) or floating-point Engineering Units
(Variation 3). For an Integrating Deadband, the value set will be the difference value in
Count Seconds (Variations 1 and 2) or Engineering Unit Seconds (Variation 3) (i.e.: The
integral over time of the difference between the last reported value and the current value).
Object 34 Variation 1 uses a 16-bit unsigned integer data representation. Deadbands are
positive values, the range of deadbands that can be represented is 0–65535 (0x0–
0xFFFF).
Object 34 Variation 2 uses a 32-bit unsigned integer data representation. Deadbands are
positive values, the range of deadbands that can be represented is 0–4294967295 (0x0–
0xFFFFFFFF).
Object 34 Variation 3 uses the short real (32-bit) floating-point format specified in the
IEEE 754 standard. While this format permits negative values, deadbands should only be
set to positive values (0.0–+INF).
Implementation notes:
A deadband of zero will permit any change to generate an event and a deadband of the
full range of the variable will prevent events from ever being generated. Hence selecting a
deadband of 4294967295 prevents event generation from any integer analog input, and
selecting a value of +INF (positive infinity) prevents event generation from any floatingpoint analog input object.
Any negative floating-point deadband value is equivalent to a zero deadband, as any
change in the input will be larger than the deadband. A device receiving a negative
floating-point deadband value should convert (or report) this to be a zero deadband value.
In systems that use fixed deadbands, setting the deadband value to the maximum range of
the analog input will inhibit event generation for that input. For example: An 8-bit analog
input may have a range of -128–127, setting the reporting deadband for this point to 255
(or more) will prevent all event reporting for that point.
If a Read request for Object 34 Variation 1 is issued, any point deadband value greater
than 65535 will be reported in the response as the value 65535 (the largest value that can
be reported in a 16-bit unsigned integer). A Read request for Object 34 Variation 2 should
be issued if integer deadband values greater than 65535 must be reported correctly.
The response to a Read request for Object 34 Variation 0 may include any variation of
Object 34, in accordance with the slave device’s capabilities and configuration. Note that
if the device is capable of reporting Object 34 Variation 3 (floating-point), then the
device must be configurable to only report data using Variations 1 and 2, in accordance
with the requirements stated in DNP Technical Bulletin 9804-006.
A slave device that supports Object 34 is not required to maintain deadband values
through reset (when it sets IIN Bit 7), and may revert to configured (or default) deadband
values on reset. If the slave device preserves updated deadband values through reset, then
this should be noted in the device profile.
Any deadband values altered by the use of Object 34 prior to the slave reset may be lost.
The DNP Master is responsible for re-sending any updated deadband values to the slave
after a slave reset if this is deemed necessary.
September 10, 1998
2 of 6
9809-001.doc
Affected Documentation:
DNP V3.00 Object Library
Chapter 6: Analog Input Object Definitions
Updated Device Profile Document
Details:
16-Bit Analog Input Reporting Deadband Object
Data Object 34 Variation 1
Type: Static, Not in Class 0
Description:
The Analog Deadband Object is an information object used to allow a DNP
device to report the magnitude of the deadband of an Analog Input Object, or to
permit the master station to alter the deadband of an Analog Input Object. This
object may be specified with the Read command (master requests slave to return
the deadband value), Write command (master alters the deadband value) or
Response command (when the slave supplies the data in response to the master’s
Read command).
The deadband value field contains the value of the deadband.
This object is NOT returned in response to a Read request of Class 0 data.
The index number identifying a deadband object is the index number of the
corresponding Analog Input Object (Object 30).
Object Coding:
Deadband Value
15
SQ1 { Deadband Value
}
0
= UI16 [0..15] <0..65535>
NOTES:
•
This object is valid with the Application Layer function codes Read, Write
and Response. The object will only be included in a Response message if
specifically requested in a Read message.
•
For analog inputs having fixed deadbands, the Deadband Value is the
deadband count value. For analog inputs using integrating deadbands, the
Deadband Value is the integrated deadband in count-seconds.
•
The response to a Read request using Variation 1 will report the value 65535
for any deadband value that is greater than 65535.
September 10, 1998
3 of 6
9809-001.doc
32-Bit Analog Input Reporting Deadband Object
Data Object 34 Variation 2
Type: Static, Not in Class 0
Description:
The Analog Deadband Object is an information object used to allow a DNP
device to report the magnitude of the deadband of an Analog Input Object, or to
permit the master station to alter the deadband of an Analog Input Object. This
object may be specified with the Read command (master requests slave to return
the deadband value), Write command (master alters the deadband value) or
Response command (when the slave supplies the data in response to the master’s
Read command).
The deadband value field contains the value of the deadband.
This object is NOT returned in response to a Read request of Class 0 data.
The index number identifying a deadband object is the index number of the
corresponding Analog Input Object (Object 30).
Object Coding:
Deadband Value
31
SQ1 { Deadband Value
}
0
= UI32 [0..31] <0..4294967295 >
NOTES:
•
This object is valid with the Application Layer function codes Read, Write
and Response. The object will only be included in a Response message if
specifically requested in a Read message.
•
For analog inputs having fixed deadbands, the Deadband Value is the
deadband count value. For analog inputs using integrating deadbands, the
Deadband Value is the integrated deadband in count-seconds.
September 10, 1998
4 of 6
9809-001.doc
Floating Point Analog Input Reporting Deadband Object
Data Object 34 Variation 3
Type: Static, Not in Class 0
Description:
The Analog Deadband Object is an information object used to allow a DNP
device to report the magnitude of the deadband of an Analog Input Object, or to
permit the master station to alter the deadband of an Analog Input Object. This
object may be specified with the Read command (master requests slave to return
the deadband value), Write command (master alters the deadband value) or
Response command (when the slave supplies the data in response to the master’s
Read command).
The deadband value field contains the value of the deadband in the 32-bit short
real format specified in the IEEE 754 Standard. This is as described for the value
field of Object 30 Variation 5 (Refer to DNP Technical Bulletin 9804-006).
This object is NOT returned in response to a Read request of Class 0 data.
The index number identifying a deadband object is the index number of the
corresponding Analog Input Object (Object 30).
Object Coding:
Deadband Value
S Exponent
Mantissa
0 7
0
22
0
*S = Sign, should only be zero (positive value)
SQ1 { Value
=
R32 { Sign = BS1 [0] <0, positive; 1, negative>
Exponent = UI8 [0..7] <0..255>
Mantissa = UI23 [0..22] <0..223-1>
}
}
NOTES:
•
This object is valid with the Application Layer function codes Read, Write
and Response. The object will only be included in a Response message if
specifically requested in a Read message.
•
For analog inputs having fixed deadbands, the Deadband Value is the
deadband engineering unit value. For analog inputs using integrating
deadbands, the Deadband Value is the integrated deadband in engineering
unit-seconds.
•
If a negative value is received (Sign bit set), this should be interpreted as a
zero value.
September 10, 1998
5 of 6
9809-001.doc
•
September 10, 1998
The +INF (positive infinity) value is represented by a Sign bit of zero, an
Exponent of 255 and a Mantissa of 0 (i.e.: the deadband value of
0x7F800000).
6 of 6
9809-001.doc
DNP Technical Bulletin 9701-001
Data Link Restart Recovery
Issue:
The data link had a problem when one station or the other is powered down and up
without the other stations knowledge. The first poll to a remote device failed because the
remote has not yet received a LINK RESET frame. Without application retries,
communications may not be recovered for the polling interval, perhaps hours or days.
Resolution:
Following a restart or power-up, prior to receiving a Reset Link frame both Master and
Slave devices must respond with a data link layer CONFIRM NACK having DFC=0
when they receive a frame having FCV=1 (SEND/CONFIRM), rather than just
discarding the frame. A power up failure will now be detected quickly by not having to
wait for retries to be completed.
Upon receipt of the NACK , the Data Link layer will make the indication to the
application layer to determine the course of action.
It is further recommended that upon receiving an indication of a transaction failure due to
a NACK:
•
•
A Master Device performs an immediate application layer retry, if appropriate.
A Slave device always perform an immediate application layer retry.
This will prevent the first transaction after power up from failing.
Affected Documents:
DNP 3.0 Data Link Layer Protocol Description
Chapter 3 DNP Data Link Description
Data Link Function Codes
Reset
January 15, 1996
1 of 1
9701-001.doc
DNP Technical Bulletin 9701-002
Control Relay Output Block Minimum Implementation
Issue:
The DNP User’s Group required the Subset Definition be amended to include a list of
minimum subset options in the Control Relay Output Block.
Resolution:
The following is a minimum implementation, given that appropriate hardware exists. If a
particular function is not supported by the hardware, the Slave device must return value 4
(operation not supported) in the Status field.
FIELD:
Trip/Close
Clear
Queue
Code
Count
On-Time
Off-Time
Status
MINIMUM IMPLEMENTATION:
See following table. Invalid with Code values of Latch On or Latch Off.
Set to 0. Only used for continuously repeating commands.
Set to 0. Only used for continuously repeating commands.
See following table. Must be Pulse On if Trip/Close is not NULL.
Set to 1. Only used if the command is to be performed multiple times.
Set to 0 unless Code value is Pulse On. See following table.
Set to 0. Only used for Pulse Off values of Code or Count greater than 1.
Set to 0 in the output request.
Function Desired
Trip/Close
Code
On-Time
Latching Relay ON
NULL (0)
Latch On (3)
Zero (ignored)
Latching Relay OFF
NULL (0)
Latch Off (4)
Zero (ignored)
Unpaired Momentary Relay (e.g Pushbutton, Alarm)
NULL (0)
Pulse On (1)
Non-zero
Trip Breaker/Relay or Raise Transformer Tap
Trip (2)
Pulse On (1)
Non-zero
Close Breaker/Relay or Lower Transformer Tap
Close (1)
Pulse On (1)
Non-zero
Addressing Issues
There are two possible ways to provide access to Trip/Close or Raise/Lower relays:
2 Points Per Address - Both operations are performed specifying the same DNP point
number. The value of the Trip/Close field selects the appropriate one of a pair of relays.
1 Point Per Address - The Trip or Raise operation is performed on a different DNP point
number than the Close or Lower operation. The remote device may return a Status of 4
(operation not supported) if an inappropriate operation is performed.
The “2 Points Per Address” method is not recommended for new designs.
January 15, 1996
1 of 2
9701-002.doc
DNP Technical Bulletin 9701-002
Control Relay Output Block Minimum Implementation
(Continued)
The next version of the DNP V3.00 Data Object Library shall be updated to redefine the
Trip/Close field as:
Paired Operation = BS2[ 6..7] <00, NULL; 01, Close|Lower; 10, Trip| Raise>
On-Time
It is recommended that if a device’s hardware only supports one pulse width (specified by
On-Time), it does not reject other values but simply ignores the specified width. This
will help with interoperability.
Documentation
The addressing method for Trip/Close or Raise/Lower operations and any features
supported in addition to the minimum specified above must be described in the Device
Profile Document. In particular, the method used for variable Raise/Lower operations
(variable On-Time, or variable Count, or neither) must be documented. Any features not
supported because of lack of hardware must also be documented.
Affected Documentation:
DNP 3.0 Data Object Library
Chapter 4 Binary Output Object Definitions
DNP 3.0 Subset Definitions
Chapter 4 Implementation Rules and Recommendations
Operating Binary Outputs
Updated Device Profile Document
January 15, 1996
2 of 2
9701-002.doc
DNP Technical Bulletin 9701-003
Cold/Warm Restart Sequence
Issue:
The DNP User’s Group required a definition for a standard implementation for
Cold/Warm Restart implementation sequence. It was previously unclear when a remote
should actually perform a restart after receiving a restart request:
•
immediately after transmitting the response
•
after receiving a data link confirm to the response
•
after receiving an application confirm
Resolution:
It is recommended that neither data link layer nor application layer confirmation be
requested when sending a response to a Cold Restart or Warm Restart request.
This implies that restart should begin immediately after sending the response. Devices
that cannot be sure exactly when the response will be completely sent can wait a suitably
large time and “pad” that time into the master wait time returned in the response.
Affected Documentation:
DNP V3.00 Application Layer Protocol Description
Chapter 4 Detailed Function Code Descriptions
Cold Restart (Function Code 13)
Warm Restart (Function Code 14)
January 15, 1996
1 of 1
9701-003.doc
DNP Technical Bulletin 9701-004
Octet (Character) Strings Objects 110 and 111
Issue:
The DNP User’s Group required a definition for a standard object for Octet (Character)
strings. The need arose to transport ASCII or other data of varying lengths. Initial uses
considered were for Passwords or other character strings, but other uses have arisen as
well.
Resolution:
A new object, Object 110, is defined as an Octet String Object. The variation within the
object represents the length for the Octet string. Devices are not required to support any
particular length of string. The event object associated for the Octet String Object is
Object 111.
NOTE:
Reading and Writing of 8 bit memory locations could be implemented using this object
together with absolute addressing qualifiers.
Please refer to the following Data Link Object Definitions for Details.
Affected Documentation:
DNP V3.00 Object Library
Chapter to be determined
August 21, 1996
1 of 3
9701-004.doc
Octet String Object
Data Object 110 - Variation = Octet string length
Type: Static
Description:
The Octet String Object represents a value from 0 to 255. Each 8 bit data element may
contain a variety of information from ASCII passwords to configuration details. This
object is not included in Class 0 poll response. The variation within the object represents
the length. For this object only read, write and response function codes are permitted.
Object Coding:
Current Value [0]
7
0
Current Value [N-1]
7
0
OSN = SQ1 { Current Value = UI [0..7] <0..255>}
where N = variation which is the length of the octet string
August 21, 1996
2 of 3
9701-004.doc
Octet String Event Object
Data Object 111 - Variation = Octet string Length
Type: Event
Description:
The Octet String Event Object represents an event value from 0 to 255. Each 8 bit data
element may contain a variety of information from ASCII passwords to configuration
details. The variation within the object represents the length. For this object only read,
response and unsolicited response function codes are permitted.
Object Coding:
Current Value [0]
7
0
Current Value [N-1]
7
0
OSN = SQ1 { Current Value = UI [0..7] <0..255>}
where N = variation which is the length of the octet string
August 21, 1996
3 of 3
9701-004.doc
DNP 3.0 Technical Bulletin 9701-006
Extended Engineering Units for Floating Point Objects
Issue:
The DNP User’s Group required new engineering unit definitions for Floating Point
Objects.
Resolution:
The following “Units” codes have been added to all floating point objects defined within
DNP:
20
quantity having no unit of measurement
21
m3 /s (volumetric flow in cubic meters per second)
22
kPa (pressure in kilopascals)
255
units unknown or undefined
23 to 254
remain available for future assignment
Affected Documentation:
DNP V3.00 Data Object Library
Chapter 6 Analog Input Object Definitions
Analog Input
Data Object 30 Variations
Frozen Analog Input
Data Object 31 Variations
Analog Change Event
Data Object 32 Variations
Frozen Analog Event
Data Object 33 Variations
Chapter 7 Analog Output Object Definitions
Analog Output Status
Data Object 40 Variations
Analog Output Block
Data Object 41 Variations
Chapter 13 Alternate Numeric Object Definitions
Floating Point
Data Object 100 Variations
(object 100 is no longer recommended)
August 21, 1996
1 of 1
5 to 7
7 to 9
5 to 7
5 to 7
3 to 5
3 to 5
1 to 3
9701-006.doc
DNP 3.0 Technical Bulletin 9704-007
Implementation Rules for Reset Link Frames
Issue:
The implementation of Reset Link Frames has recently caused some controversy with
different vendors providing differing subsets. To avoid possible incompatibilities, the
following resolutions were adopted.
Resolution:
•
•
•
A device is not required to transmit a RESET LINK frame if that device
transmits only SEND/NO REPLY EXPECTED frames.
A device must not require the reception of a RESET LINK frame before
accepting SEND/NO REPLY EXPECTED frames.
Any device receiving a RESET LINK frame must respond with a CONFIRM ACK. Any other response or no response at all indicates that the receiver is
unable to perform the link reset.
Affected Documentation:
DNP V3.00 Data Link Layer
Chapter 3: DNP Data Link Description
Data Link Function Codes
April 16, 1997
1 of 1
9704-007.doc
Distributed Network Protocol (DNP3-2001)
DNP3-2001
Intelligent Electronic Device (IED)
Certification Procedure
Subset Level 1
Version 2.1
5-July-01
Disclaimer Statement
DNP User Group documents and publications are not consensus documents.
Information contained in this and other works has been obtained from sources
believed to be reliable, and reviewed by credible members of the DNP User Group
and/or the DNP User Group Technical Committee. Neither the DNP Users Group
nor any authors/developers of DNP documentation guarantee, and each such person
expressly disclaims responsibility for ensuring, the accuracy or completeness of any
information published herein, and neither the DNP Users Group nor its
authors/developers shall be responsible for any errors, omissions, or damages
arising out of use of this document.
Likewise, while the author/developer and publisher believe that the information and
guidance given in this work serves as an enhancement to users, all parties must rely
upon their own skill and judgment when making use of it. Neither the author nor the
publisher assumes any liability to anyone for any loss or damage caused by any
error or omission in the work, whether such error or omission is the result of
negligence or any other cause. Any and all such liability is disclaimed.
This statement was developed by the DNP User Group Technical Committee and
represents the considered judgment of a group of software developers with expertise
in the subject field. The DNP User Group is a global forum for users and
implementers of the protocol and promotes implementers and developer
information and interaction exchange. This work is published with the
understanding that the DNP User Group and its authors/developers are supplying
information through this publication, not attempting to render engineering or other
professional services. If such services are required, the assistance of an appropriate
professional should be sought. The DNP User Group is not responsible for any
statements and/or opinions advanced in this publication.
NOTICE OF RIGHTS - DNP USERS GROUP
The contents of this manual are the property of the DNP Users Group. Revisions or
additions to the definition and functionality of the DNP Protocol cannot be made
without express written agreement from the DNP Users Group or its duly authorised
party. In addition, no part of this document may be altered or revised or added to in
any form or by any means, except as permitted by written agreement with the DNP
Users Group or a Party duly authorised by the DNP Users Group.
The DNP Users Group has made every reasonable attempt to ensure the
completeness and accuracy of this document. However, the information contained in
this manual is subject to change without notice, and does not represent a
commitment on the part of the DNP Users Group. An update program for DNP
documents is provided upon request by the DNP Users Group.
TRADEMARK NOTICES
DNP is a trademark of the DNP Users Group. Any brand and product names
mentioned in this document are trademarks or registered trademarks of their
respective companies.
Copyright  2001 DNP Users Group. All rights reserved.
Revision History
Date
18-Jan-99
15-Dec-99
Version
1.00
1.01
Sections affected
ALL
see errata sheet for 1.00
10-July-00
2.00
5-July-01
2.1
8.11.1.1
8.11.2.5.9
8.6.5.1
8.6.5.4
8.2.1.1
8.2.1.2.11 - 15
8.4.1.1
8.4.1.2.8 - 12
6
6.6.2.5
8.2.1.2.10, step 1
8.4.1.2.7, step 1
8.6.5.4
8.2.5
8.2.1.1, 8.2.1.2.3,
8.2.2.1, 8.2.2.2.2,
8.4.1.1, 8.4.1.2.3,
8.4.2.1, 8.4.2.2.2
8.2.4.1 - 8.2.4.2,
8.4.4.1 - 8.4.4.2
Section 9, Appendices A
and B
DNP3-2001 IED Certification Procedure
Subset Level 1
Reason for change
Initial Release
Fixes inconsistencies and errors
Designates protocol as DNP3-1999 (formerly DNP V3.00 with
extensions)
Added required parameter - maximum number of unsolicited retries
Added test procedure from TB9912-002
Added desired response to addresses 0xFFFE and 0xFFFD
Added test procedure from TB9912-003
Added requirements for Control SBO retries
Added test procedures from TB2000-002
Added requirements for Analog Output SBO retries
Added test procedures from TB2000-002
Removed reference to function code 1
Removed function code 0xD1 from table
Replace "end testing of Binary Output, SBO" with "skip this section"
Replace "end testing of Analog Output, SBO" with "skip this section"
Added step 2 - "Issue a link reset using link control block 0xC0"
Added test procedure from TB2000-006
Added status code in error response as required in TB2001-01
Added test procedures from TB2001-001
Removed; the information required for these sections is not available
and may not be for some time.
Page i
Rev 2.1 – 5-July-01
Contents
1
2
3
4
5
6
7
8
Overview.............................................................................................................................................................................. 1
1.1
Protocol specification .................................................................................................................................................. 1
Notes.................................................................................................................................................................................... 1
Definitions ........................................................................................................................................................................... 3
3.1
General......................................................................................................................................................................... 3
3.2
Internal Indications ...................................................................................................................................................... 3
3.3
Error Responses ........................................................................................................................................................... 3
3.4
Changes or Events ....................................................................................................................................................... 4
3.4.1
§ Rules ................................................................................................................................................................. 4
Reference Documents .......................................................................................................................................................... 5
Pretest Review ..................................................................................................................................................................... 5
5.1
Device Profile Review ................................................................................................................................................. 5
5.2
Equipment Review....................................................................................................................................................... 5
Link Layer ........................................................................................................................................................................... 6
6.1
Reset Link and Passive Confirm support ..................................................................................................................... 6
6.1.1
Desired Behavior ................................................................................................................................................. 6
6.1.2
Test Procedure ..................................................................................................................................................... 6
6.2
Test Link...................................................................................................................................................................... 7
6.2.1
Desired Behavior ................................................................................................................................................. 7
6.2.2
Test Procedure ..................................................................................................................................................... 7
6.3
Request Link Status ..................................................................................................................................................... 7
6.3.1
Desired Behavior ................................................................................................................................................. 7
6.3.2
Test Procedure ..................................................................................................................................................... 7
6.4
Test Retries .................................................................................................................................................................. 8
6.4.1
Desired Behavior ................................................................................................................................................. 8
6.4.2
Test Procedure ..................................................................................................................................................... 8
6.5
§ DIR and FCV Bits..................................................................................................................................................... 8
6.5.1
Desired Behavior ................................................................................................................................................. 8
6.5.2
Test Procedure ..................................................................................................................................................... 8
6.6
Data Link Rejects Invalid Frames................................................................................................................................ 9
6.6.1
Desired Behavior ................................................................................................................................................. 9
6.6.2
Test Procedure – Primary Frames ........................................................................................................................ 9
6.6.2.1 Invalid Start Octets ........................................................................................................................................ 10
6.6.2.2 Invalid Primary Function Code...................................................................................................................... 10
6.6.2.3 Invalid Destination Address........................................................................................................................... 10
6.6.2.4 Invalid CRC ................................................................................................................................................... 10
6.6.2.5 § Invalid FCV ................................................................................................................................................ 11
6.6.3
Test Procedure – Secondary Frames .................................................................................................................. 11
6.6.3.1 Invalid Start Octets ........................................................................................................................................ 11
6.6.3.2 Invalid Secondary Function Code.................................................................................................................. 12
6.6.3.3 Invalid Destination Address........................................................................................................................... 12
6.6.3.4 Invalid CRC ................................................................................................................................................... 12
Transport Layer ................................................................................................................................................................. 13
7.1
Desired Behavior ....................................................................................................................................................... 13
7.2
Test Procedure ........................................................................................................................................................... 13
Application Layer .............................................................................................................................................................. 14
8.1
Binary Output Status.................................................................................................................................................. 14
8.1.1
Desired Behavior ............................................................................................................................................... 14
8.1.2
Test Procedure ................................................................................................................................................... 14
8.2
Binary Outputs........................................................................................................................................................... 14
8.2.1
Select Before Operate ........................................................................................................................................ 15
8.2.1.1 Desired Behavior ........................................................................................................................................... 15
DNP3-2001 IED Certification Procedure
Subset Level 1
Page ii
Rev 2.1 – 5-July-01
8.2.1.2 Test Procedure ............................................................................................................................................... 16
8.2.1.2.1 Binary Output, SBO, 0x28.......................................................................................................................16
8.2.1.2.2 Binary Output, SBO, 0x17.......................................................................................................................16
8.2.1.2.3 Binary Output, SBO, To Uninstalled Point..............................................................................................16
8.2.1.2.4 Binary Output, SBO, Execute Issued After Timeout ...............................................................................16
8.2.1.2.5 Binary Output, SBO, Execute to Different Point Than Select .................................................................16
8.2.1.2.6 Binary Output, SBO, Execute On Time does not match Select On Time................................................16
8.2.1.2.7 Binary Output, SBO, Execute Off Time does not match Select Off Time...............................................17
8.2.1.2.8 Binary Output, SBO, Select using a supported Control Code, Execute using a different Control Code .17
8.2.1.2.9 Binary Output, SBO, Select 0x28, Execute 0x17 ....................................................................................17
8.2.1.2.10 Binary Output, SBO, Configurable Device............................................................................................17
8.2.1.2.11 Binary Output, SBO, Same Sequence Number Select Retries...............................................................17
8.2.1.2.12 Binary Output, SBO, Incrementing Sequence Number Select Retries ..................................................17
8.2.1.2.13 Binary Output, SBO, Same Sequence Number Operate Retries ............................................................18
8.2.1.2.14 Binary Output, SBO, Incrementing Sequence Number Operate Retries................................................18
8.2.1.2.15 Binary Output, SBO, Sequence number checking .................................................................................18
8.2.2
Direct Operate with Acknowledge..................................................................................................................... 18
8.2.2.1 Desired Behavior ........................................................................................................................................... 18
8.2.2.2 Test Procedure ............................................................................................................................................... 19
8.2.2.2.1 Binary Output, Direct Operate .................................................................................................................19
8.2.2.2.2 Binary Output, Direct Operate to Uninstalled Point ................................................................................19
8.2.2.2.3 Binary Output, Direct Operate, Configurable Device..............................................................................19
8.2.3
Direct Operate, No Acknowledge ...................................................................................................................... 19
8.2.3.1 Desired Behavior ........................................................................................................................................... 19
8.2.3.2 Test Procedure ............................................................................................................................................... 19
8.2.3.2.1 Binary Output, Direct Operate, No Acknowledge ...................................................................................19
8.2.3.2.2 Binary Output, Direct Operate, No Acknowledge, to an Uninstalled Point.............................................20
8.2.3.2.3 Binary Output, Direct Operate, No Acknowledge, Configurable Device ................................................20
8.2.4
Multiple Object Requests................................................................................................................................... 20
8.2.4.1 Desired Behavior ........................................................................................................................................... 20
8.2.4.2 Test Procedure ............................................................................................................................................... 20
8.2.5
Control Code Support ........................................................................................................................................ 21
8.2.5.1 Desired Behavior ........................................................................................................................................... 21
8.2.5.2 Test Procedure ............................................................................................................................................... 21
8.2.5.2.1 Binary Output, Complementary Function Support ..................................................................................21
8.2.5.2.2 Binary Output, Single Function Support..................................................................................................22
8.3
Analog Output Status................................................................................................................................................. 22
8.3.1
Desired Behavior ............................................................................................................................................... 23
8.3.2
Test Procedure ................................................................................................................................................... 23
8.4
Analog Outputs .......................................................................................................................................................... 23
8.4.1
Select Before Operate ........................................................................................................................................ 23
8.4.1.1 Desired Behavior ........................................................................................................................................... 24
8.4.1.2 Test Procedure ............................................................................................................................................... 24
8.4.1.2.1 Analog Output, SBO, 0x28 ......................................................................................................................24
8.4.1.2.2 Analog Output, SBO, 0x17 ......................................................................................................................25
8.4.1.2.3 Analog Output, SBO, to Uninstalled Point ..............................................................................................25
8.4.1.2.4 Analog Output, SBO, Execute Issued After Time-out.............................................................................25
8.4.1.2.5 Analog Output, SBO, Execute Value does not match Select Value ........................................................25
8.4.1.2.6 Analog Output, SBO, Select 0x28, Execute 0x17....................................................................................25
8.4.1.2.7 Analog Output, SBO, Configurable Device.............................................................................................25
8.4.1.2.8 Analog Output, SBO, Same Sequence Number Select Retries ................................................................26
8.4.1.2.9 Analog Output, SBO, Incrementing Sequence Number Select Retries....................................................26
8.4.1.2.10 Analog Output, SBO, Same Sequence Number Operate Retries ...........................................................26
8.4.1.2.11 Analog Output, SBO, Incrementing Sequence Number Operate Retries...............................................26
8.4.1.2.12 Analog Output, SBO, Sequence number checking ................................................................................26
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8.4.2
Direct Operate with Acknowledge..................................................................................................................... 27
8.4.2.1 Desired Behavior ........................................................................................................................................... 27
8.4.2.2 Test Procedure ............................................................................................................................................... 27
8.4.2.2.1 Analog Output, Direct Operate ................................................................................................................27
8.4.2.2.2 Analog Output, Direct Operate, to Uninstalled Point ..............................................................................27
8.4.2.2.3 Analog Output, Direct Operate, Configurable Device .............................................................................27
8.4.3
Direct Operate, No Acknowledge ...................................................................................................................... 28
8.4.3.1 Desired Behavior ........................................................................................................................................... 28
8.4.3.2 Test Procedure ............................................................................................................................................... 28
8.4.3.2.1 Analog Output, Direct Operate, No Acknowledge ..................................................................................28
8.4.3.2.2 Analog Output, Direct Operate, No Acknowledge, to an Uninstalled Point............................................28
8.4.3.2.3 Analog Output, Direct Operate, No Acknowledge, Configurable Device ...............................................28
8.4.4
Multiple Object Requests................................................................................................................................... 28
8.4.4.1 Desired Behavior ........................................................................................................................................... 28
8.4.4.2 Test Procedure ............................................................................................................................................... 28
8.5
Class Data .................................................................................................................................................................. 29
8.5.1
Class 0................................................................................................................................................................ 29
8.5.1.1 Desired Behavior ........................................................................................................................................... 30
8.5.1.2 Test Procedure ............................................................................................................................................... 30
8.5.2
Class 1................................................................................................................................................................ 30
8.5.2.1 Desired Behavior ........................................................................................................................................... 31
8.5.2.2 Test Procedure ............................................................................................................................................... 31
8.5.2.2.1 Class 1 Data, 0x06 ...................................................................................................................................31
8.5.2.2.2 Class 1 Data, 0x07 ...................................................................................................................................32
8.5.2.2.3 Class 1 Data, 0x08 ...................................................................................................................................32
8.5.2.2.4 § Class 1 Data Without Confirm..............................................................................................................32
8.5.3
Class 2................................................................................................................................................................ 33
8.5.3.1 Desired Behavior ........................................................................................................................................... 33
8.5.3.2 Test Procedure ............................................................................................................................................... 33
8.5.3.2.1 Class 2 Data, 0x06 ...................................................................................................................................33
8.5.3.2.2 Class 2 Data, 0x07 ...................................................................................................................................34
8.5.3.2.3 Class 2 Data, 0x08 ...................................................................................................................................34
8.5.3.2.4 § Class 2 Data Without Confirm..............................................................................................................34
8.5.4
Class 3................................................................................................................................................................ 35
8.5.4.1 Desired Behavior ........................................................................................................................................... 35
8.5.4.2 Test Procedure ............................................................................................................................................... 35
8.5.4.2.1 Class 3 Data, 0x06 ...................................................................................................................................35
8.5.4.2.2 Class 3 Data, 0x07 ...................................................................................................................................36
8.5.4.2.3 Class 3 Data, 0x08 ...................................................................................................................................36
8.5.4.2.4 § Class 3 Data Without Confirm..............................................................................................................36
8.5.5
Multiple Object Request .................................................................................................................................... 37
8.5.5.1 Desired Behavior ........................................................................................................................................... 37
8.5.5.2 Test Procedure ............................................................................................................................................... 37
8.5.5.2.1 Multiple Object Request, Class 1, 2, and 3 ..............................................................................................37
8.5.5.2.2 Multiple Object Request, Class 1, 2, 3, and 0 ..........................................................................................37
8.5.6
Class Assignment Verification........................................................................................................................... 38
8.5.6.1 Desired Behavior ........................................................................................................................................... 38
8.5.6.2 Test Procedure ............................................................................................................................................... 38
8.6
Indications.................................................................................................................................................................. 38
8.6.1
Restart ................................................................................................................................................................ 38
8.6.1.1 Desired Behavior ........................................................................................................................................... 38
8.6.1.2 Test Procedure ............................................................................................................................................... 38
8.6.2
Bad Function...................................................................................................................................................... 39
8.6.2.1 Desired Behavior ........................................................................................................................................... 39
8.6.2.2 Test Procedure ............................................................................................................................................... 39
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8.6.3
Object Unknown ................................................................................................................................................ 39
8.6.3.1 Desired Behavior ........................................................................................................................................... 39
8.6.3.2 Test Procedure ............................................................................................................................................... 39
8.6.4
Local .................................................................................................................................................................. 39
8.6.4.1 Desired Behavior ........................................................................................................................................... 39
8.6.4.2 Test Procedure for Devices with Global Remote Supervisory Control.......................................................... 39
8.6.4.3 Test Procedure for Devices with Individual Remote Supervisory Control .................................................... 39
8.6.5
Broadcast Address and All Stations Indication.................................................................................................. 40
8.6.5.1 Desired Behavior ........................................................................................................................................... 40
8.6.5.2 § Test Procedure ............................................................................................................................................ 40
8.6.5.3 Test Procedure ............................................................................................................................................... 40
8.6.5.4 § Test Procedure, Confirmed Response Options ........................................................................................... 41
8.6.6
Buffer Overflow................................................................................................................................................. 41
8.6.6.1 Desired Behavior ........................................................................................................................................... 41
8.6.6.2 Test Procedure ............................................................................................................................................... 41
8.6.6.2.1 Buffer Overflow, Binary Input Change Event Buffers ............................................................................41
8.6.6.2.2 Buffer Overflow, Analog Input Change Event Buffers ...........................................................................41
8.6.6.2.3 Buffer Overflow, Binary Counter Change Event Buffers........................................................................42
8.7
Time........................................................................................................................................................................... 42
8.7.1
Delay Measurement ........................................................................................................................................... 42
8.7.1.1 Desired Behavior ........................................................................................................................................... 42
8.7.1.2 Test Procedure ............................................................................................................................................... 42
8.7.2
Synchronization ................................................................................................................................................. 43
8.7.2.1 Desired Behavior ........................................................................................................................................... 43
8.7.2.2 Test Procedure ............................................................................................................................................... 43
8.8
Cold Restart ............................................................................................................................................................... 43
8.8.1
Desired Behavior ............................................................................................................................................... 43
8.8.2
Test Procedure ................................................................................................................................................... 43
8.9
Application Layer Fragmentation .............................................................................................................................. 43
8.9.1
Use of FIR, FIN and SEQUENCE in Fragmentation......................................................................................... 43
8.9.1.1 Desired Behavior ........................................................................................................................................... 43
8.9.1.2 Test Procedure ............................................................................................................................................... 44
8.9.2
§ Use of Confirmation in Fragmentation ........................................................................................................... 44
8.9.2.1 § Desired Behavior ........................................................................................................................................ 44
8.9.2.2 § Test Procedure ............................................................................................................................................ 44
8.10 Multi-Drop Support ................................................................................................................................................... 45
8.10.1 Desired Behavior ............................................................................................................................................... 45
8.10.2 Test Procedure ................................................................................................................................................... 45
8.11 Unsolicited Responses ............................................................................................................................................... 45
8.11.1 Desired Behavior ............................................................................................................................................... 46
8.11.1.1 Configuration ................................................................................................................................................. 46
8.11.1.2 Sequence Numbers and Confirmation ........................................................................................................... 46
8.11.1.3 Restart Behavior............................................................................................................................................. 46
8.11.1.4 Runtime Behavior .......................................................................................................................................... 46
8.11.1.5 Unsolicited and Polled Responses ................................................................................................................. 47
8.11.2 Test Procedure ................................................................................................................................................... 47
8.11.2.1 Unsolicited Response Configuration/Startup ................................................................................................. 47
8.11.2.2 Unsolicited Response - Class 1 Data ............................................................................................................. 48
8.11.2.3 Unsolicited Response - Class 2 Data ............................................................................................................. 49
8.11.2.4 Unsolicited Response - Class 3 Data ............................................................................................................. 49
8.11.2.5 Unsolicited and Polled Responses ................................................................................................................. 50
8.11.2.5.1 Transmits data-filled unsolicited responses ...........................................................................................50
8.11.2.5.2 Clears transmitted data upon confirmation ............................................................................................50
8.11.2.5.3 Processes non-READ requests immediately ..........................................................................................50
8.11.2.5.4 Defers READ requests until after confirmation received ......................................................................50
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8.11.2.5.5 Defers READ requests until after confirmation timeout........................................................................51
8.11.2.5.6 Abandons READ requests upon subsequent non-READ requests.........................................................51
8.11.2.5.7 Abandons READ requests upon subsequent READ requests ................................................................51
8.11.2.5.8 Inhibits Unsolicited responses until after polled confirmation...............................................................51
8.11.2.5.9 Retries unsolicited responses configurable number of times .................................................................52
8.11.2.6 Unsolicited Responses Off............................................................................................................................. 52
8.12 § Collision Avoidance ............................................................................................................................................... 53
8.12.1 Desired Behavior ............................................................................................................................................... 54
8.12.2 Test Procedure ................................................................................................................................................... 54
9 Appendix A – DNP3 Reference Sheet............................................................................................................................... 55
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1 Overview
It is the purpose of this document to describe a set of tests that will determine an Intelligent Electronic Devices’ (IED)
compliance with the Distributed Network Protocol (formly known as DNP V3.00). This certification procedure is designed
specifically to determine an IED’s compliance to level 1 of the Subset Definitions. A device must pass all of the tests to be
considered compliant to this procedure.
1.1 Protocol specification
The protocol is defined by the Basic 4 Document set (Link Layer, Transport Layer, Application Layer, and Subset
Definitions), Technical Notes published by the Technical Committee, and this Certification Procedure. The protocol defined
by these documents shall be denoted DNP3-2001.
Sections in this document marked with the symbol "§" constitute new requirements or clarifications beyond the Basic 4
Document set. These sections may create interoperability problems with implementations done prior to the publication of
this test procedure. However, the DNP Users' Group approved these changes at the annual 1999 meeting based on strong
recommendation from the Technical Committee. These requirements and clarifications will greatly improve interoperability
and extensive efforts have been made to minimize the impact on existing implementations.
2 Notes
1.
This procedure is an attempt to produce interoperability between Master and IED devices, although such interoperability
can NOT be guaranteed. However, it does gives reasonable assurance that Masters which can be configured to match
items in the IED Device Profile Document will interoperate.
2.
Wherever the following procedures generate a specific number of events, it is acceptable to use an alternate number
supported by the device provided that the intent of the test is still satisfied.
3.
This is not a factory acceptance test, but a protocol test. Therefore only selected outputs will be tested to verify protocol
operation.
4.
Unless otherwise specified, all Application Layer retries are disabled.
5.
If not explicitly stated all tests imply verification that all points in a normal operating state are reported with all flag bits
except the ONLINE bit clear and the ONLINE bit is set. Alternatively, verification that the object is reported with the
“without flags” variation is also implied.
6.
Sections marked with three asterisks (***) extend the requirements of the device beyond DNP3-2000.
7.
Record the point numbers used in all tests in the log.
8.
All application layer tests use unconfirmed link services using a request link control block of 0xC4 unless specified
otherwise.
9.
When time tagged events are reported the certification procedures do not measure the absolute accuracy of the reported
times. They do however verify that the reported times are updated in a reasonable manner. The Device Profile Document
specifies the accuracy with which the device measures the event. This accuracy is guaranteed by the vendor, not the
certification procedures.
10. If not explicitly stated all tests imply verification that a response to a request has the same application sequence number
as the request. If the request generates multiple application fragments also verify that the application sequence number of
each subsequent fragment increments by 1 modulo 16.
11. These tests assume that the device will only generate events as controlled by the tester, as specified in the procedure.
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12. It is strongly recommended that the tester run the device for a least 24 hours at some point during the testing to insure
that it does not exhibit any unusual or unexpected behavior. This is not a requirement for compliance to this procedure.
13. Responses to all properly formed requests, must result in either the specific action or behavior described in the protocol
or in a correctly-formed, appropriate protocol error response. In addition, devices must continue to operate without
interruption or anomalous behavior in response to properly or improperly formed requests.
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3 Definitions
3.1 General
Master
Device that sends DNP application function codes 0-23.
Slave
Device that sends DNP application function code 0,128,129 (also known as “IED”).
Operate This is an action taken by the Slave in response to a Master DNP request. This action does not include
transmission of a response. Examples of an operation are an audible relay click, change in an LED status, or
change in the internal state of the Slave. Note that some operations are difficult to observe without intimate
knowledge of the Slave device. The inability to observe an operation does not mean that an operation failed to
take place.
Request
Any message from a Master to a Slave where a response from the Slave is expected.
Response Message from Slave caused by a Master Request. Responses are classified as follows:
•
No response: No octets are sent by Slave
•
Link only response: 10 octet message consisting of only a link layer message
•
Null Response: Message containing a 17-octet link/transport/application response with no error IIN bits set
and no application objects.
•
Normal Response: Message containing an application response which has no error IIN bits set, and has no
objects which indicate errors
•
All responses must begin with the same application sequence number as the corresponding request.
•
For Multi-fragment responses the first fragment must have the same sequence number as the request and
each subsequent fragment must increment the sequence number by 1 modulo 16.
3.2 Internal Indications
IIN
IIN1-1
IIN1-2
IIN1-3
IIN1-4
IIN1-5
IIN1-7
IIN2-0
IIN2-1
IIN2-2
Octets 3 and 4 of the application response header. Bits are named IINx-y. x=1 for first transmitted octet and 2 for
second transmitted octet. y=bit number where 0=least significant bit. Refer to the Basic Four Application Layer
section 3.6 and the Subset Definitions section 4.1.1 for detailed explanations of the IIN bits. The following is a
summary of the definitions.
Class 1 event data available. Can be set at any time and does not indicate an error condition.
Class 2 event data available. Can be set at any time and does not indicate an error condition.
Class 3 event data available. Can be set at any time and does not indicate an error condition.
Time synchronization required. Can be set at any time and does not indicate an error condition.
Local mode. Set if some points are uncontrollable via DNP.
Device restart. Set only under specific conditions. Does not indicate an error condition.
Function Unknown. Generally means that the function code (octet 2 of the request header) cannot be processed.
Object Unknown. Generally means that the function code could be processed but the object group / variation
could not be processed.
Parameter Error. Generally indicates that both the function code and object group / variation could be processed
but that the qualifier / range field is in error.
3.3 Error Responses
Error IIN bits IIN bits that indicate a request error (i.e., IIN2-0 or IIN2-1 or IIN2-2).
Error Response A response that has any or all of the Error IIN bits set which may also contain data.
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Unexpected Error Response
Slaves may generate responses with any or all of the following:
• unexpected bits in the IIN set
• unexpected bits in any returned flags set
• unexpected status code errors
Any unexpected responses must be noted by the tester and “explained” in the test log.
3.4 Changes or Events
This section clarifies processing rules related to the following objects.
Change Object
Name
Corresponding Static Object
Object
Name
Object
Binary Input Change
2
Binary Input
1
Counter Change Events
22
Counter
20
Frozen Counter Change Events
23
Frozen Counter
21
Analog Change Events
32
Analog Input
30
Frozen Analog Change Events
33
Frozen Analog Input
31
Table 3-1
1.
2.
3.
The term “significant change” refers to any of the synonymous terms: “event” or “change event”.
Change Objects and Static Objects are related in that a significant change in a point’s static value results in the creation
of a corresponding Change Object entry
A significant change for a point is defined to occur:
• for a binary point, on any change in state, and
• for a numeric point, on any change in value greater than the point’s threshold
3.4.1 § Rules
A device may claim that it supports a specific Change Object if and only if processing for that Change Object can be
configured to adhere to the following rules.
1.
2.
3.
4.
Change processing must be supported for all points in the corresponding Static Object.
The determination that a point has undergone a significant change can be determined only by using information from that
point’s current or past value. Decisions based on information about any other point, directly or indirectly, are explicitly
forbidden.
For numeric Change Objects, the Device Profile must clearly specify the algorithm used for each point or set of points
that specifies how the deadband(s) for those points are determined.
All changes must be returned to a host that issues a request for any specific Change Object, limited only by qualifier and
range codes in the request.
Some devices may decide to limit the set of points included in Change Object processing (in violation of rule 1), or to invoke
a more complicated algorithm for determining a significant change (in violation of rule 2). While these implementations may
be useful in specific instances, such devices may not check compliance with the corresponding Change Object in their Device
Profile Documentation unless the device is configurable to conform to the rules above.
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4 Reference Documents
•
•
•
•
•
DNP Version 3.00 Data Link Layer
DNP Version 3.00 Transport Functions
DNP Version 3.00 Application Layer
DNP Version 3.00 Data Object Library Layer
DNP Version 3.00 Subset Definitions Version 2.00 (§ Version 3.00)
5 Pretest Review
Before testing proceeds it is necessary to review documentation and equipment supplied by the vendor for completeness and
appropriateness to the application. In particular the vendor must have provided the test facility with the following items.
• Device Profile Document
• Device to be tested
• Wiring Diagrams for
• Power
• Communications (e.g. RS232, RS485, Bell 202, IEEE 802.3)
• Input connections
5.1 Device Profile Review
Before connecting any equipment the Device Profile should be carefully reviewed. This document describes the vendors’
specification of the behavior of the device. This behavior should be compared to Level 1 requirements and any discrepancies
resolved before testing proceeds. Specifically the Device Profile should indicate that the device:
•
•
Responds to all Level 1 requests that a slave device is required to parse.
Responds to Level 1 requests only with Objects/Variations and Qualifiers that a Level 1 master is required to parse.
If a device generates any response requiring a higher level master to parse it, the following actions should be taken:
•
•
•
Testing can continue.
It must be noted in the test results that the device is Level 1 compliant for requests only.
The required Master Level must be noted in the test results.
5.2 Equipment Review
Before testing proceeds, the device will be examined to insure the proper equipment is available for the following:
• Physical interfaces present and compatible.
• Wiring diagrams and equipment necessary for Input stimulation.
• Input power specifications.
• If it is not readily apparent whether an output point has operated, the vendor must supply to the tester a point number and
method to determine whether or not a binary control and/or analog output has operated.
A manufacturer’s representative should be available by phone to answer questions during the testing of the device.
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6 Link Layer
Any DNP device is required to passively implement all link layer services. Specifically, this means that a device need not
request link layer service but must support any services requested by another device. For example:
• A device can choose not to request link layer confirms but MUST respond with a link layer confirm if requested to do
so.
• A device can choose not to request link layer reset if it is using unconfirmed link services but MUST respond with a link
layer confirm if a link layer reset is requested.
• § A device must respond to all unconfirmed link requests (i.e. function codes 0, 4, 9) without a preceding link reset.
The following tests are designed to verify this functionality.
6.1 Reset Link and Passive Confirm support
6.1.1 Desired Behavior
•
•
•
•
•
•
The Device under test (DUT) must respond to a link reset with a link confirm.
DUT must respond to application layer data requests using unconfirmed link services without requiring a link reset.
DUT must not respond to application layer data requests using confirmed link services without a preceding link reset.
DUT must respond to application layer data requests using confirmed link services after a link reset has been issued.
DUT must acknowledge but not otherwise respond to requests with the wrong FCB.
DUT must issue a data link reset if transmitting requests that require a data link confirm.
6.1.2 Test Procedure
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
14.
15.
16.
17.
18.
19.
20.
21.
22.
23.
24.
25.
26.
27.
Cycle power to the DUT.
Request Class 0 data (Object 60 Variation 1) using Qualifier Code 0x06 and link control block 0xC4.
Verify that the DUT responds with a valid message.
Request Class 0 data (Object 60 Variation 1) using Qualifier Code 0x06 and link control block 0xF3.
Verify that the DUT either sends a NACK with the DFC bit clear or does not respond.
Request Class 0 data (Object 60 Variation 1) using Qualifier Code 0x06 and link control block 0xD3.
Verify that the DUT either sends a NACK with the DFC bit clear or does not respond.
Issue a link reset using link control block 0xC0.
Verify that the DUT responds with a link layer confirm (link control block 0x00).
Request Class 0 data (Object 60 Variation 1) using Qualifier Code 0x06 and link control block 0xF3.
Verify that the DUT responds with a link layer confirm and a valid application layer response.
Perform repeated requests of Class 0 data (Object 60 Variation 1) using Qualifier Code 0x06 and alternating link control
blocks 0xD3 and 0xF3.
Verify that the DUT responds with a link layer confirm and a valid application layer response for each request.
Issue a link reset using link control block 0xC0.
Verify that the DUT responds with a link layer confirm (link control block 0x00).
Request Class 0 data (Object 60 Variation 1) using Qualifier Code 0x06 and link control block 0xD3.
Verify that the DUT responds with a link layer confirm (link control block 0x00) and no application response.
Request Class 0 data (Object 60 Variation 1) using Qualifier Code 0x06 and link control block 0xF3.
Verify that the DUT responds with a link layer confirm and a valid application layer response.
Request Class 0 data (Object 60 Variation 1) using Qualifier Code 0x06 and link control block 0xF3.
Verify that the DUT responds with a link layer confirm (link control block 0x00) and no application response.
If the DUT cannot be configured to request data link confirms when transmitting, continue testing at section 6.2.
Configure the DUT to request data link confirm when transmitting.
Cycle power to the DUT.
Request Class 0 data (Object 60 Variation 1) using Qualifier Code 0x06 and link control block 0xC4.
Verify that the DUT responds by sending a data link reset (control block 0x40).
Send a data link acknowledge (control block 0x80).
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28. Verify that the DUT responds with a valid message having control block 0x73. This is the response to the Class 0 data
request, including a request for data link confirm.
29. Issue a data link NACK with DFC clear (control block 0x81).
30. If the DUT then issues a data link reset (control block 0x40), respond by sending an acknowledge control block 0x80). If
the DUT then repeats the Class 0 response message (control block 0x73), it has functioned correctly, and this test is
complete, continue testing at section 6.2.
31. If the DUT did not issue a link reset at step 30, steps 25 through 28 should be repeated as shown above. DUT responses
other than those of steps 26 and 28 indicate incorrect operation.
6.2 Test Link
6.2.1 Desired Behavior
•
•
•
The DUT must respond with a Link Confirm - ACK if the FCB bits are correct in the test request.
Otherwise, the DUT must respond with the last secondary confirm frame. This behavior is not tested since it was deemed
by the Technical Committee as too difficult to test in a reliable manner.
If the DUT receives a test link frame without a previous link reset, the DUT must either not respond or respond with a
NACK with DFC = 0.
6.2.2 Test Procedure
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
14.
15.
16.
Cycle power to the DUT.
Request a Link Test Frame using link control block 0xF2.
Verify that the DUT responds with a Confirm - NACK with DFC=0 (link control code 0x01) or does not respond.
Issue a Link Reset using link control block 0xC0.
Request a Link Test Frame using link control block 0xF2.
Verify that the DUT responds with a Confirm - ACK (link control code 0x00).
Request a Link Test Frame using link control block 0xD2.
Verify that the DUT responds with a Confirm - ACK (link control code 0x00).
Cycle power to the DUT.
Request a Link Test Frame using link control block 0xD2.
Verify that the DUT responds with a Confirm - NACK with DFC=0 (link control code 0x01) or does not respond.
Issue a Link Reset using link control block 0xC0.
Request a Link Test Frame using link control block 0xF2.
Verify that the DUT responds with a Confirm - ACK (link control code 0x00).
Request a Link Test Frame using link control block 0xD2.
Verify that the DUT responds with a Confirm - ACK (link control code 0x00).
6.3 Request Link Status
6.3.1 Desired Behavior
•
•
When issued a Request Link Status message, the DUT must respond with a valid Status of Link message.
The DUT must ignore FCB when FCV = 0.
6.3.2 Test Procedure
1.
2.
3.
4.
5.
Cycle power to the DUT.
Request a Link Status Frame using link control block 0xC9.
Verify that the DUT responds with a valid link status message with link control block 0x0B or 0x1B.
Request a Link Status Frame using link control block 0xE9.
Verify that the DUT responds with a valid link status message with link control block 0x0B or 0x1B.
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6.4 Test Retries
6.4.1 Desired Behavior
•
•
•
•
•
•
DUTs are not required to support link layer retries.
The rest of these behaviors apply only to DUTs that support link layer retries.
§ The DUT must be able to disable retries through configuration.
If the device requests a link layer confirm and does not receive it within a specified period of time (LINK TIMEOUT), it
shall retransmit the link frame. It shall do this n times where n is a specified number of retries before aborting
transmission (LINK RETRYCOUNT).
If configured to enable link layer confirms on primary transmissions, the DUT must perform retries on all
SEND/CONFIRM and REQUEST/RESPOND frames.
Both LINK TIMEOUT and LINK RETRYCOUNT must be specified in the Device Profile Document or they can
optionally be configurable parameters.
6.4.2 Test Procedure
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
14.
15.
16.
17.
18.
19.
20.
If the DUT does not support link layer confirms or link layer retries on primary transmissions, continue testing in the
next section.
Configure the device to enable link layer confirms on primary transmissions and if retries are configurable, set them to a
reasonable value.
Cycle power to the DUT.
Request Class 0 data (Object 60 Variation 1) using Qualifier Code 0x06 and link control block 0xC4.
Verify that the DUT sends a RESET LINK frame. Do not send a data link CONFIRM frame.
Verify that the DUT waits LINK TIMEOUT and then retransmits the link frame.
Verify that it repeats this exactly LINK RETRYCOUNT times.
Request Class 0 data (Object 60 Variation 1) using Qualifier Code 0x06 and link control block 0xC4.
Verify that the DUT responds with a RESET LINK frame. Send a data link CONFIRM.
Verify that the DUT sends a valid application layer response in a SEND/CONFIRM USER DATA frame. Do not send a
data link CONFIRM frame.
Verify that the DUT waits LINK TIMEOUT and then retransmits the link frame.
Verify that it repeats this exactly LINK RETRYCOUNT times.
If it is possible to cause the DUT to send TEST LINK, RESET USER PROCESS, or REQUEST LINK STATUS, cause
it to do so, but do not respond in each case. Repeat steps 11 and 12 for each of these frames that can be generated.
Request Class 0 data (Object 60 Variation 1) using Qualifier Code 0x06 and link control block 0xC4.
Verify that the DUT responds with a RESET LINK frame. Send a data link CONFIRM.
Verify that the DUT sends a valid application layer response in a SEND/CONFIRM USER DATA frame. Do not send a
data link CONFIRM frame.
Verify that the DUT waits LINK TIMEOUT and then retransmits the link frame.
Send a data link CONFIRM.
Verify that no further retries are sent.
If it is possible to cause the DUT to send TEST LINK, RESET USER PROCESS, or REQUEST LINK STATUS, cause
it to do so, but do not respond in each case. Repeat steps 18 and 19 for each of these frames that can be generated.
6.5 § DIR and FCV Bits
6.5.1 Desired Behavior
•
•
The DUT must clear (set to zero) the DIR bit in each data link frame it transmits.
The DUT must set the FCV bit to zero in all frames except SEND/CONFIRM User Data and SEND/CONFIRM Test
Link. These frames are tested elsewhere.
6.5.2 Test Procedure
1.
If the DUT is capable of requesting data link confirmations, configure it to NOT request data link confirmations.
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2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
Cycle power to the DUT.
Prepare and send a READ request for Class 0 data (Object 60 Variation 1) using Qualifier Code 0x06 and a link control
block 0xC4.
Verify the response from the DUT uses data link control block 0x44 i.e. Unconfirmed User Data with the DIR bit not set
and the FCV bit not set.
If the DUT can generate RESET USER PROCESS or REQUEST LINK STATUS, cause it to do so and verify none of
these frames have the DIR or FCV bit set.
If the DUT can generate TEST LINK, cause it to do so and verify that these frames have the DIR bit clear and FCV bit
set.
If the DUT is not capable of requesting data link confirmations, no further testing is required in this section. If the DUT
is capable of requesting data link confirmations, configure it to do so.
Cycle power to the DUT.
Prepare and send a READ request for Class 0 data (Object 60 Variation 1) using Qualifier Code 0x06 and a link control
block 0xC4.
Verify the DUT first sends a frame with data link control block 0x40, i.e. RESET LINK with DIR=0 and FCV=0.
Reply with a data link CONFIRM - ACK.
Verify the DUT sends a frame with data link control block 0x73 i.e. SEND/CONFIRM USER DATA with FCV=1 and
FCB = 1.
Configure DUT to NOT request data link confirmations.
6.6 Data Link Rejects Invalid Frames
6.6.1 Desired Behavior
The DUT must detect errors due to transmission line errors or the incorrect functioning of other devices. It must therefore not
respond, either at a data link layer or application layer, to frames that are otherwise valid but have one of the following errors:
• Incorrect start sequence
• Incorrect destination address
• Incorrect CRC
• Invalid function code
• Invalid FCV (Frame Count Valid) bit
For an invalid function code or invalid FCV, the DUT may also respond with LINK SERVICE NOT IMPLEMENTED.
NOTES:
• These procedures do not test whether the DUT rejects frames having the DIR bit set incorrectly. Implementers of Slave
IEDs must, however, clear this bit (0) in all their transmissions to aid monitoring their device’s output on protocol
analyzers. This is tested in section “DIR and FCV Bits”.
• It is optional whether devices choose to filter frames based on source address, and is therefore not tested here. The
Device Profile Document indicates whether or not filtering is performed based on the source address.
6.6.2 Test Procedure – Primary Frames
Before performing the remainder of these tests:
1. Cycle power to the DUT.
2. Issue a link reset using link control block 0xC0.
3. Verify that the DUT responds with a link layer confirm (link control block 0x00).
4. Request Class 0 data (Object 60 Variation 1) using Qualifier Code 0x06 and link control block 0xF3.
5. Verify that the DUT responds with a link layer confirm (link control block 0x00).
6. Verify that the DUT responds with application layer data.
To perform the remainder of this test, a general-purpose protocol analyzer capable of generating any sequence of data is
necessary. If a DNP-specific protocol analyzer is being used for testing, it should be used to monitor the exchange between
the general-purpose analyzer and the DUT.
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6.6.2.1 Invalid Start Octets
1.
Prepare a READ request for Class 0 data (Object 60 Variation 1) using Qualifier Code 0x06 and a link control block
0xD3.
2. Modify the frame so it begins with an invalid initial start octet (e.g. 0x09) instead of 0x05.
3. Modify the CRC of the data link layer header so the CRC is correct for the invalid start octet.
4. Send the request.
5. Wait several seconds.
6. Verify that the DUT does not send a link layer confirm or application layer response.
7. Modify the frame so it begins with 0x05, but the second start octet is invalid (e.g. 0xff).
8. Modify the CRC of the data link layer header so the CRC is correct for the invalid start octet.
9. Send the request.
10. Wait several seconds.
11. Verify that the DUT does not send a link layer confirm or application layer response.
12. Repeat this test once using different start octet values.
6.6.2.2 Invalid Primary Function Code
1.
2.
3.
4.
5.
6.
7.
Prepare a READ request for Class 0 data (Object 60 Variation 1) using Qualifier Code 0x06 and a link control block of
0xD3.
Modify the frame so the control field contains the correct settings of the DIR, PRM, FCB and FCV fields, but has an
invalid function code, e.g. 0xD5. Alter the CRC of the data link layer header so the CRC is correct for the invalid control
field.
Send the request.
Wait several seconds.
Verify that the DUT either does not send a link layer confirm, or responds with a valid LINK SERVICE NOT
IMPLEMENTED frame (control field 0x0F).
Verify that the DUT does not send an application layer response.
Repeat this test once with a different invalid function code.
6.6.2.3 Invalid Destination Address
1.
2.
3.
4.
Send a READ request to different address. Note: For devices that can be configured to represent multiple logical devices
(i.e. can respond to requests directed to more than one address), ensure that the selected address is not one of the other
valid addresses configured for the device.
Wait several seconds.
Verify that the DUT does not send a link layer confirm or application layer response.
Repeat this test once with a different destination address.
6.6.2.4 Invalid CRC
1.
Prepare a READ request for Class 0 data (Object 60 Variation 1) using Qualifier Code 0x06 and a link control block
0xD3.
2. Modify the frame so the CRC of the data link layer header is incorrect.
3. Send the request.
4. Wait several seconds.
5. Verify that the DUT does not send a link layer confirm or application layer response.
6. Modify the frame so the CRC of the data link layer header is correct but the CRC of the application layer request is
incorrect.
7. Send the request.
8. Wait several seconds.
9. Verify that the DUT does not send a link layer confirm or application layer response.
10. Repeat this test once with different incorrect CRC values.
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6.6.2.5 § Invalid FCV
1.
2.
3.
4.
5.
6.
7.
8.
9.
Prepare a READ request for Class 0 data (Object 60 Variation 1) using Qualifier Code 0x06 and a link control block
0xC3, i.e. SEND/CONFIRM USER DATA, but with FCV=0 (incorrect).
Send the request.
Wait several seconds.
Verify that the DUT does not send a link layer confirm or application layer response. The DUT may respond with a link
layer frame with function code LINK SERVICE NOT IMPLEMENTED.
Prepare a READ request for Class 0 data (Object 60 Variation 1) using Qualifier Code 0x06 and a link control block
0xD4, i.e. SEND/NO CONFIRM USER DATA, but with FCV=1 (incorrect).
Send the request.
Wait several seconds.
Verify that the DUT does not send a link layer confirm or application layer response. The DUT may respond with a link
layer frame with function code LINK SERVICE NOT IMPLEMENTED.
Repeat steps 5-8 using the control blocks in the following table:
Code
Description
Notes
C2
Test Link
FCV = 0 incorrect
D0
RESET LINK
FCV=1 incorrect, FCB = 0 ignored
D9
Link Status Request
FCV=1 incorrect, FCB = 0 ignored
6.6.3 Test Procedure – Secondary Frames
The tests in this section are optional, and must pass only if the DUT requests data link confirmations and performs retries.
The retries are used to detect whether the device processed the data link layer confirmation.
Before performing these tests:
1. Configure the device to enable link layer confirms on primary transmissions and if retries are configurable set them to a
reasonable value.
2. Cycle power to the DUT.
3. Request Class 0 data (Object 60 Variation 1) using Qualifier Code 0x06 and link control block 0xC4.
4. Verify that before responding with application layer data, the DUT sends a RESET LINK frame. Send a data link
CONFIRM – ACK frame in reply.
5. Verify the DUT responds with application layer data, requesting data link confirmation.
6. Send a valid CONFIRM – ACK frame in reply.
To perform the remainder of this test, a general-purpose protocol analyzer capable of generating any sequence of data is
necessary. If a DNP-specific protocol analyzer is being used for testing, it should be used to monitor the exchange between
the general-purpose analyzer and the DUT.
6.6.3.1 Invalid Start Octets
1.
2.
3.
4.
5.
6.
7.
8.
9.
Request Class 0 data (Object 60 Variation 1) using Qualifier Code 0x06 and link control block 0xC4.
Verify the DUT responds with application layer data, requesting data link confirmation.
Send a CONFIRM – ACK frame modified so its start octet is invalid (e.g. 0x09).
Verify that the DUT waits LINK TIMEOUT and then retransmits the link frame.
Request Class 0 data (Object 60 Variation 1) using Qualifier Code 0x06 and link control block 0xC4.
Verify the DUT responds with application layer data, requesting data link confirmation.
Send a CONFIRM – ACK frame modified so the start octet is correct (0x05), but the second octet is incorrect (e.g.
0xff).
Verify that the DUT waits LINK TIMEOUT and then retransmits the link frame.
Repeat this test once with different start octet values.
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6.6.3.2 Invalid Secondary Function Code
1.
2.
3.
4.
5.
Request Class 0 data (Object 60 Variation 1) using Qualifier Code 0x06 and link control block 0xC4.
Verify the DUT responds with application layer data, requesting data link confirmation.
Send a CONFIRM – ACK frame modified so the DIR, PRM and DFC bits of the control field are correct, but the
function code is invalid (e.g. 0x03). Ensure that the CRC is correct for the invalid function code value.
Verify that the DUT waits LINK TIMEOUT and then retransmits the link frame.
Repeat this test once with a different function code value.
6.6.3.3 Invalid Destination Address
1.
2.
3.
4.
5.
6.
This test may be performed with a DNP-specific test set.
Request Class 0 data (Object 60 Variation 1) using Qualifier Code 0x06 and link control block 0xC4.
Verify the DUT responds with application layer data, requesting data link confirmation.
Send a CONFIRM – ACK frame to a destination address that is not that of the DUT.
Verify that the DUT waits LINK TIMEOUT and then retransmits the link frame.
Repeat this test once with a different destination address.
6.6.3.4 Invalid CRC
1.
2.
3.
4.
5.
Request Class 0 data (Object 60 Variation 1) using Qualifier Code 0x06 and link control block 0xC4.
Verify the DUT responds with application layer data, requesting data link confirmation.
Send a CONFIRM – ACK frame modified such that the CRC is incorrect.
Verify that the DUT waits LINK TIMEOUT and then retransmits the link frame.
Repeat this test once with a different CRC value.
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7 Transport Layer
Whenever FIR, FIN and sequence numbers are referenced in this section they refer to the definitions present in the transport
header which is reproduced here for convenience.
bit 7
FIN
Transport Header
bit 6
bits 5-0
FIR
Sequence number
Table 7-1
7.1 Desired Behavior
•
•
If the DUT contains enough data to cause the reply to an application request to be larger than one Link Protocol Data
Unit, it is required to,
a) Set the proper FIR and FIN bits.
b) Set the correct sequence information.
c) Distribute the data correctly.
d) Signify to the initiating station that the reply contains multiple LPDU’s
e) Provide the appropriate information for assembly at the receiving station.
If the device does not contain enough data, then the FIR and FIN bits must signify that there is only one LPDU in the
reply.
7.2 Test Procedure
1.
2.
3.
4.
5.
6.
7.
Cycle power to the DUT.
Request Class 0 data (Object 60 Variation 1) using Qualifier Code 0x06.
Verify that the DUT responds with a valid message.
If the DUT’s reply contains more than 249 octets then verify that the first response message sets the FIR bit to a one, the
FIN bit is set to zero.
Verify subsequent messages to assure that the FIR bit is zero, the FIN bit is zero, and the sequence number increments
by one.
Verify that the last message has the FIR bit is zero and the FIN bit is one, signifying the last data fragment, and the SEQ
value increments by one.
If the DUT’s reply contains less than 250 octets in the Data Link Frame then the FIR bit is set to one and the FIN bit is
also set to one.
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8 Application Layer
8.1 Binary Output Status
The binary output status object represents the current state and status of the associated binary output. The status is an 8-bit
flag field (repeated here for your convenience):
Flag Bit
0
1
2
3
4
5
6
7
Value
ONLINE - 0=off-line, 1= on-line
RESTART - 0=normal, 1= restart
COMMUNICATION LOST - 0=normal, 1=lost
REMOTE FORCED DATA - 0=normal, 1=forced
LOCAL FORCED DATA - 0=normal, 1=forced
0
0
STATE - 0, 1
Table 8-1
8.1.1 Desired Behavior
•
•
•
If the device supports binary outputs the device must respond to a Binary Output read request with a binary output status
object (object 10 Variation 2) using qualifiers 0x00 or 0x01.
If the device does not support binary outputs the device must respond to a Binary Output read request with a Null
Response.
Optionally, the device can return an error response with IIN2-1.
8.1.2 Test Procedure
1.
2.
3.
4.
5.
Issue a request for Object 10 Variation 0 using the all data qualifier 0x06.
If the device supports Binary Outputs verify that the DUT responds with a Binary Output Status object (Object 10
Variation 2).
Verify that the data is reported using either 8 bit start/stop indexing (qualifier 0x00) or 16 bit start/stop indexing
(qualifier 0x01).
If the device does not support Binary Outputs verify that the DUT responds with a Null Response. The device can
optionally set IIN2-1.
Verify that flag behavior complies with Section 2, Note #5.
8.2 Binary Outputs
§ If a device supports control outputs, it is required to be configurable to support all three modes of operation of control,
namely Select Before Operate, Direct Operate, and Direct Operate No Acknowledgment. A device may be configurable to
disable any subset of the modes. If a device has been configured to reject a particular mode, it must return a control status
value of 4 (control operation not supported for this point).
It is the hosts’ responsibility to determine the appropriate control mechanism. It is also the hosts’ responsibility to perform
select before operate control when it is unacceptable to have the control point operated more than once. This is typically a
configuration item in the host and is the responsibility of the end user to configure properly.
It is the outstations’ responsibility to perform the control operation if a correct control dialog has been issued from the host.
If the DUT is configurable in a manner such that points can be uninstalled or disabled, the device must be configured with at
least one Binary Output point installed or enabled before proceeding with the test procedure.
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8.2.1 Select Before Operate
Select before operate control is used under circumstances when it is absolutely imperative that the control point operate only
once. An example of this is a recloser. The host first initiates the select portion of the dialog. The outstation then echoes the
exact control request byte for byte to the host. Note that the encapsulation information need not match, but that the object,
variation, qualifier, and all object data must match exactly. The host then sends the execute portion of the dialog. The object,
variation, qualifier, and all object data must match exactly byte for byte the data sent in the select message. If this message
matches the select message byte for byte and it is received within the configured acceptable delay between select and execute
the outstation must operate the control point.
8.2.1.1 Desired Behavior
The following assumes that the device does not support control operations:
• If the device does not support control outputs, it must respond to a select with an Error Response setting IIN2-1.
• An Error Response with IIN2-2 set is an invalid response.
• No further testing in this section is necessary.
The following assumes that the device supports control operations:
• The maximum select to execute delay time must be specified in the Device Profile Document.
• The DUT responds to matching select and execute requests by echoing each request with the status field set to 0.
The specified control operates.
• The DUT responds to selecting an uninstalled control point by returning an error response with IIN2-2 set and a
status code of 4. The control point does not operate.
• The DUT responds to executing an installed control point after the configured acceptable select to execute delay by
echoing the execute and setting the status field to 1 [Execute received after timeout]. The control point does not
operate
• The DUT responds to a non-matching execute with a status field of 2 [No previous matching select] and does not
operate the control under the following conditions:
• No prior select issued
• On time mismatch
• Off time mismatch
• Control code mismatch
• The DUT operates various selected control points.
• The DUT supports 8 and 16 bit point indexing.
The following assumes that the device supports control operations and were added as a result of Technical Bulletin TB2000002 (Control Retries):
• The DUT must accept retries on the select portion of the control dialog that increment the application sequence
number between retries. In this case the select-to-operate timer must be restarted after reception of each select.
• The DUT must accept retries on the select portion of the control dialog that do not increment the application
sequence number between retries. In this case the select-to-operate timer must remain unaltered by the reception of
each additional select.
• The DUT must reject any operate that does not:
$ contain a application layer sequence number that is exactly one greater (modulo 16) than the previously
accepted select.
$ match the object portion of the select message byte for byte, excluding the application header.
• The DUT must accept retries on the operate portion of the control dialog that does not increment the application
sequence number between retries. The DUT must echo the operate command but must not operate the control more
than once.
The following assumes that the device does support control operations, however there are no control points installed/enabled:
• If the device does not have any control outputs installed, it must respond to a select with an Error Response setting
IIN2-1 or IIN2-2.
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8.2.1.2 Test Procedure
8.2.1.2.1 Binary Output, SBO, 0x28
1.
2.
3.
4.
5.
6.
Issue a select using Object 12 Variation 1 to an installed point using 16 bit indexing (qualifier 0x28), a control code
supported by the device and an appropriate on time/off time.
If the device does not support control outputs, verify that the DUT responds with a Error Response with IIN2-1 set. End
testing of Binary Output SBO.
Verify that the DUT responds by echoing the select message exactly.
Immediately issue a matching execute.
Verify that the DUT echoes the execute.
Verify that the selected control operates.
8.2.1.2.2 Binary Output, SBO, 0x17
1.
2.
3.
4.
5.
Issue a select using Object 12 Variation 1 to a different installed point using 8 bit indexing (qualifier 0x17), a control
code supported by the device and an appropriate on time/off time.
If the device does support control outputs, verify that the DUT responds by echoing the select message exactly.
Immediately issue a matching execute.
Verify that the DUT echoes the execute.
Verify that the selected control operates.
8.2.1.2.3 Binary Output, SBO, To Uninstalled Point
1.
2.
3.
Issue a select using Object 12 Variation 1 to an uninstalled point using 16 bit indexing (qualifier 0x28) using a control
code supported by the device and an appropriate on time/off time.
Verify that the DUT responds by returning an error response with IIN2-2 set and a status code of 4.
Verify that no control point operates.
8.2.1.2.4 Binary Output, SBO, Execute Issued After Timeout
1.
2.
3.
4.
5.
Issue a select using Object 12 Variation 1 to an installed point using 8 bit indexing (qualifier 0x17), a control code
supported by the device and an appropriate on time/off time.
Verify that the DUT responds by echoing the select message exactly.
Wait 1 second past the configured maximum select to execute delay time.
Issue a matching execute and verify that the DUT echoes the execute with the control status field set to 1[Execute
received after timeout].
Verify that no control point operates.
8.2.1.2.5 Binary Output, SBO, Execute to Different Point Than Select
1.
2.
3.
4.
5.
Issue a select to Object 12 Variation 1 to an installed point using 8 bit indexing (qualifier 0x17), a control code supported
by the device and an appropriate on time/off time.
Verify that the DUT responds by echoing the select message exactly.
Immediately issue an execute to Object 12 Variation 1 to a different installed point using 8 bit indexing (qualifier 0x17),
the same control code as the select, and the same on time/off time as the previous select.
Verify that the DUT echoes the execute with the control status field set to 2 [No previous matching select].
Verify that no control point operates.
8.2.1.2.6 Binary Output, SBO, Execute On Time does not match Select On Time
1.
2.
3.
4.
5.
Issue a select using Object 12 Variation 1 to an installed point using 8 bit indexing (qualifier 0x17), a control code
supported by the device and an appropriate on time/off time.
Verify that the DUT responds by echoing the select message exactly.
Immediately issue a execute to Object 12 Variation 1 to an installed point using 8 bit indexing (qualifier 0x17), the same
control code as the select, the on time incremented by 1 and the same off time as the previous select.
Verify that the DUT echoes the execute with the control status field set to 2 [No previous matching select].
Verify that no control point operates.
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8.2.1.2.7 Binary Output, SBO, Execute Off Time does not match Select Off Time
1.
2.
3.
4.
5.
Issue a select using Object 12 Variation 1 to an installed point using 8 bit indexing (qualifier 0x17), a control code
supported by the device and an appropriate on time/off time.
Verify that the DUT responds by echoing the select message exactly.
Immediately issue an execute to Object 12 Variation 1 to an installed point using 8 bit indexing (qualifier 0x17), the
same control code as the select, same on time as the previous select and the off time incremented by 1.
Verify that the DUT echoes the execute with the control status field set to 2 [No previous matching select].
Verify that no control point operates.
8.2.1.2.8 Binary Output, SBO, Select using a supported Control Code, Execute using a different
Control Code
1.
2.
3.
4.
5.
Issue a select using Object 12 Variation 1 to an installed point using 8 bit indexing (qualifier 0x17), a control code
supported by the device and an appropriate on time/off time.
Verify that the DUT responds by echoing the select message exactly.
Immediately issue an execute to Object 12 Variation 1 to an installed point using 8 bit indexing (qualifier 0x17), a
control code different from the previous select, and the same on time/off time as the previous select.
Verify that the DUT echoes the execute with the control status field set to 2 [No previous matching select].
Verify that no control point operates.
8.2.1.2.9 Binary Output, SBO, Select 0x28, Execute 0x17
1.
2.
3.
4.
5.
Issue a select using Object 12 Variation 1 to an installed point using 16 bit indexing (qualifier 0x28), a control code
supported by the device and an appropriate on time/off time.
Verify that the DUT responds by echoing the select message exactly.
Immediately issue an execute to Object 12 Variation 1 to an installed point using 8 bit indexing (qualifier 0x17), a
control code supported by the device and the same on time/off time as the previous select.
Verify that the DUT echoes the execute with the control status field set to 2 [No previous matching select].
Verify that no control point operates.
8.2.1.2.10 Binary Output, SBO, Configurable Device
1.
2.
3.
4.
5.
If the device is not configurable in a manner such that control points can be uninstalled or disabled, skip this section.
Configure the DUT such that all Binary Output points are uninstalled or disabled.
Issue a select using Object 12 Variation 1 to point 0 using 16 bit indexing (qualifier 0x28), a control code supported by
the device and an appropriate on time/off time.
Verify that the DUT responds by returning an error response with IIN2-1 or IIN2-2 set.
Verify that no control point operates.
8.2.1.2.11 Binary Output, SBO, Same Sequence Number Select Retries
1.
2.
3.
4.
5.
6.
7.
8.
If the DUT does not have installed binary output points, skip this section.
Issue a valid select to an installed binary output point.
Verify that the DUT echoes the object portion of the select byte for byte.
Issue the select again using the same application layer sequence number.
Verify that the DUT echoes the object portion of the select byte for byte.
Issue a valid operate, incrementing the sequence number by 1 modulo 16.
Verify that the DUT echoes the object portion of the operate byte for byte.
Verify that the DUT operates the binary output.
8.2.1.2.12 Binary Output, SBO, Incrementing Sequence Number Select Retries
1.
2.
3.
4.
5.
If the DUT does not have installed binary output points, skip this section.
Issue a valid select to an installed binary output point.
Verify that the DUT echoes the object portion of the select byte for byte.
Issue the select again incrementing the application layer sequence number by 1 modulo 16.
Verify that the DUT echoes the object portion of the select byte for byte.
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6.
7.
8.
Issue a valid operate, incrementing the sequence number by 1 modulo 16.
Verify that the DUT echoes the object portion of the operate byte for byte.
Verify that the DUT operates the binary output.
8.2.1.2.13 Binary Output, SBO, Same Sequence Number Operate Retries
1.
2.
3.
4.
5.
6.
7.
8.
9.
If the DUT does not have installed binary output points, skip this section.
Issue a valid select to an installed binary output point.
Verify that the DUT echoes the object portion of the select byte for byte.
Issue a valid operate, incrementing the sequence number by 1 modulo 16.
Verify that the DUT echoes the object portion of the operate byte for byte.
Verify that the DUT operates the binary output.
Issue the operate again using the same application layer sequence number.
Verify that the DUT echoes the object portion of the operate byte for byte.
Verify that the DUT does not operate the binary output.
8.2.1.2.14 Binary Output, SBO, Incrementing Sequence Number Operate Retries
1.
2.
3.
4.
5.
6.
7.
8.
9.
If the DUT does not have installed binary output points, skip this section.
Issue a valid select to an installed binary output point.
Verify that the DUT echoes the object portion of the select byte for byte.
Issue a valid operate, incrementing the sequence number by 1 modulo 16.
Verify that the DUT echoes the object portion of the operate byte for byte.
Verify that the DUT operates the binary output.
Issue the operate again, incrementing the sequence number by 1 modulo 16.
Verify that the DUT echoes the object portion of the operate byte for byte with a status code value of 2 (NO
MATCHING SELECT).
Verify that the DUT does not operate the binary output.
8.2.1.2.15 Binary Output, SBO, Sequence number checking
1.
2.
3.
4.
5.
6.
7.
8.
9.
If the DUT does not have installed binary output points, skip this section.
Issue a valid select to an installed binary output point.
Verify that the DUT echoes the object portion of the select byte for byte.
Issue a valid operate, incrementing the sequence number by anything but 1 modulo 16.
Verify that the DUT echoes the object portion of the operate byte for byte with a status code value of 2 (NO
MATCHING SELECT).
Verify that the DUT does not operate the binary output.
Issue a valid operate, incrementing the select sequence number by 1 modulo 16 to make sure the mismatched operate
cleared the previous select.
Verify that the DUT echoes the object portion of the operate byte for byte with a status code value of 2 (NO
MATCHING SELECT).
Verify that the DUT does not operate the binary output.
8.2.2 Direct Operate with Acknowledge
8.2.2.1 Desired Behavior
The following behavior assumes that the device does not support control operation:
• If the device does not support control outputs, it must respond to a direct operate with an Error Response setting IIN2-1.
• An Error Response with IIN2-2 set is an invalid response.
• No further testing in this section is necessary.
The following behavior assumes that the device supports control operations:
• The DUT responds to a direct operate to an uninstalled data point by returning an Error response with IIN2-2 set and a
status code of 4. The control does not operate.
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•
The DUT responds to a direct operate to an installed data point by echoing the direct operate and setting the status field
to 0. The specified control operates.
The following behavior assumes that the device does support control operations, however there are no control points
installed/enabled:
• If the device does not have any control outputs installed, it must respond to a direct operate with an Error Response
setting IIN2-1 or IIN2-2.
8.2.2.2 Test Procedure
8.2.2.2.1 Binary Output, Direct Operate
1.
2.
3.
4.
Issue a direct operate using Object 12 Variation 1 to an installed point using 8 bit indexing (qualifier 0x17), a control
code supported by the device and an appropriate on time/off time.
If the device does not support control outputs verify that the DUT responds with an Error Response with IIN2-1 set and
end testing of this section.
If the device does support control outputs verify that the DUT responds by echoing the direct operate message exactly
with status field of 0.
Verify that the specified control operates.
8.2.2.2.2 Binary Output, Direct Operate to Uninstalled Point
1.
2.
3.
Issue a direct operate using Object 12 Variation 1 to an uninstalled point using 16 bit indexing (qualifier 0x28) using a
control code supported by the device and an appropriate on time/off time.
Verify that the DUT responds by returning an Error response with IIN2-2 set and a status code of 4.
Verify that no control operates.
8.2.2.2.3
1.
2.
3.
4.
5.
Binary Output, Direct Operate, Configurable Device
If the device is not configurable in a manner such that control points can be uninstalled or disabled, end testing of Binary
Output, Direct Operate.
Configure the DUT such that all Binary Output points are uninstalled or disabled.
Issue a direct operate using Object 12 Variation 1 to point 0 using 16 bit indexing (qualifier 0x28) using a control code
supported by the device and an appropriate on time/off time.
Verify that the DUT responds by returning an error response with IIN2-1 or IIN2-2 set.
Verify that no control operates.
8.2.3 Direct Operate, No Acknowledge
8.2.3.1 Desired Behavior
•
•
The DUT must not respond to in any way to the direct operate no acknowledge.
If the device supports binary outputs and the operate message is correct then the binary output point must operate.
8.2.3.2 Test Procedure
8.2.3.2.1 Binary Output, Direct Operate, No Acknowledge
1.
2.
3.
4.
Issue a Direct Operate, No Acknowledge using Object 12 Variation 1 to an installed point using 8 bit indexing (qualifier
0x17), a control code supported by the device and an appropriate on time/off time.
Verify that the DUT does not respond.
If the device does not support control outputs, end testing of this section.
If the device does support control outputs, verify that the proper control point operates.
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8.2.3.2.2 Binary Output, Direct Operate, No Acknowledge, to an Uninstalled Point
1.
2.
3.
Issue a Direct Operate, No Acknowledge using Object 12 Variation 1 to an uninstalled point using 16 bit indexing
(qualifier 0x28) using a control code supported by the device and an appropriate on time/off time.
Verify that the DUT does not respond.
Verify that no control operates.
8.2.3.2.3
1.
2.
3.
4.
5.
Binary Output, Direct Operate, No Acknowledge, Configurable Device
If the device is not configurable in a manner such that control points can be uninstalled or disabled, end testing of Binary
Output, Direct Operate, No Acknowledge.
Configure the DUT such that all Binary Output points are uninstalled or disabled.
Issue a Direct Operate, No Acknowledge using Object 12 Variation 1 to point 0 using 16 bit indexing (qualifier 0x28)
using a control code supported by the device and an appropriate on time/off time.
Verify that the DUT does not respond.
Verify that no control operates.
8.2.4 Multiple Object Requests
8.2.4.1 Desired Behavior
•
•
The DUT must parse requests for all control operations within a single frame.
Up to a full frame of request operations must be supported.
The following assumes that the device supports control operations and were added as a result of Technical Bulletin TB2001001 (Multiple Control Object and Status Codes):
• The DUT responds to requests having more points than are supported in a single message with a status code of 8 for
at least the first point that is beyond the point count limit.
• The DUT responds to a select to an uninstalled control point by returning an error response with IIN2-2 set and a
status code of 4.
8.2.4.2 Test Procedure
1.
2.
3.
4.
5.
6.
7.
8.
9.
Review the device’s profile document to understand how many control points are supported in a single request. If this
number is one, skip to step 7.
Determine the number of installed points that can be successfully controlled in a single request. This number shall be the
smaller of:
• The number of controls supported in a single request
• The number of installed control points
• Sixteen
In a single request, issue a select to the above number of points using Object 12, Variation 1 and 16-bit indexing
(qualifier 0x28), a control code supported by the device, and an appropriate on time/off time.
Verify that the DUT response has none of IIN2-0, IIN2-1, or IIN2-2 set and that each object returns a status code of 0.
Immediately issue a matching execute.
Verify that the DUT response has none of IIN2-0, IIN2-1, or IIN2-2 set and that each object returns a status code of 0.
Verify that each of the selected controls operated. Note that controls may execute simultaneously or sequentially one
after the other.
If the number of control objects supported in a single request is greater than or equal to either
• The number of control objects that fit into a single frame or
• The number of installed control points,
skip to step 13.
In a single request, issue a select to at least one more point than is supported in a single request, each point having a
different index but otherwise able to be controlled, using Object 12, Variation 1 and 16-bit indexing (qualifier 0x28), a
control code supported by the device, and an appropriate on time/off time.
Verify that the DUT response has none of IIN2-0, IIN2-1, or IIN2-2 set, that each object except the last returns a status
code of 0, and the last object returns a status code of 8.
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10. If the DUT does not support direct operate, skip to step 13.
11. In a single request, issue a direct operate command to at least one more point than is supported in a single request, each
point having a different index but otherwise able to be controlled, using Object 12, Variation 1 and 16-bit indexing
(qualifier 0x28), a control code supported by the device, and an appropriate on time/off time.
12. Verify that the DUT response has none of IIN2-0, IIN2-1, or IIN2-2 set, that each object except the last returns a status
code of 0 and the last object returns a status code of 8. Verify that all except the last control point operated.
13. In a single request, issue a select to one installed control point and to one point that is not installed using Object 12,
Variation 1 and 16-bit indexing (qualifier 0x28), a control code supported by the device, and an appropriate on time/off
time. The installed point should be the first object in the request.
14. Verify that the DUT response has IIN2-2 bit set, that the status code returned for the installed point is 0 and the status
code returned for the non-installed point is 4.
8.2.5 Control Code Support
8.2.5.1 Desired Behavior
The following assumes that the device supports control operations and were added as a result of Technical Bulletin TB2000006 (CROB Control Codes):
• For complementary function indices, the Outstation must accept at least one of the following control code pairs:
$ 0x03 (Latch On/NUL) and 0x04 (Latch Off/NUL)
$ 0x41 (Pulse On/Close) and 0x81 (Pulse On/Trip)
•
The outstation may optionally accept both forms of complementary control code pairs. If it does:
$ control codes 0x03 (Latch On/NUL) and 0x41 (Pulse On/Close) must perform the same function
$ control codes 0x04 (Latch Off/NUL) and 0x81 (Pulse On/Trip) must perform the same function
•
For single function indices, the outstation must accept at least one of the following control codes:
$ 0x01 (Pulse On/NUL)
$ 0x03 (Latch On/NUL)
$ 0x04 (Latch Off/NUL)
$ 0x41 (Pulse On/Close)
$ 0x81 (Pulse On/Trip)
•
If the outstation accepts more than one control code for a single function index, it must perform the same function
for each control code it accepts.
8.2.5.2 Test Procedure
8.2.5.2.1 Binary Output, Complementary Function Support
1.
2.
3.
4.
If the DUT does not have installed binary output points skip this section.
If the DUT does not have installed complementary function binary output points skip this section.
If the DUT does not support the 0x03 (Latch On/NUL) and 0x04 (Latch Off/NUL) pair skip to step 8.
Issue a valid control sequence to the first installed complementary function binary output point using control code 0x03
(Latch On/NUL).
5. Verify the control operation completes successfully.
6. Issue a valid control sequence to an installed complementary function binary output point using control code 0x04 (Latch
Off/NUL).
7. Verify the complementary control operation completes successfully.
8. If the DUT does not support the 0x41(Pulse On/Close) and 0x81 (Pulse On/Trip) pair skip to step 13.
9. Issue a valid control sequence to an installed complementary function binary output point using control code 0x41(Pulse
On/Close).
10. Verify the control operation completes successfully.
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11. Issue a valid control sequence to an installed complementary function binary output point using control code 0x81 (Pulse
On/Trip).
12. Verify the complementary control operation completes successfully.
13. If the DUT does not support both the 0x03 (Latch On/NUL) and 0x04 (Latch Off/NUL) control code pair and the
0x41(Pulse On/Close) and 0x81 (Pulse On/Trip) control code pair skip to step the next section.
14. Issue a valid control sequence to an installed complementary function binary output point using control code 0x03 (Latch
On/NUL).
15. Verify the control operation completes successfully.
16. Issue a valid control sequence to the same installed complementary function binary output point using control 0x81
(Pulse On/Trip).
17. Verify that the complementary control operation completes successfully.
18. Issue a valid control sequence to the same installed complementary function binary output point using control code
0x41(Pulse On/Close).
19. Verify the complementary control operation completes successfully.
20. Issue a valid control sequence to the same installed complementary function binary output point using control 0x04
(Latch Off/NUL).
21. Verify the complementary control operation completes successfully.
8.2.5.2.2 Binary Output, Single Function Support
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
14.
15.
16.
17.
18.
If the DUT does not have installed binary output points skip this section.
If the DUT does not have installed single function binary output points skip this section.
For any point that is tested below, determine what action should happen when the control executes.
If the DUT does not support the 0x01 (Pulse On/NUL) control code for single function binary output points at this index
skip to step 7.
Issue a valid control sequence to the first installed single function binary output point using control code 0x01 (Pulse
On/NUL).
Verify the control operation in step 3 completes successfully.
If the DUT does not support the 0x03 (Latch On/NUL) control code for single function binary output points at this index
skip to step 10.
Issue a valid control sequence to the first installed single function binary output point using control code 0x03 (Latch
On/NUL).
Verify the control operation in step 3 completes successfully.
If the DUT does not support the 0x04 (Latch Off/NUL) control code for single function binary output points at this index
skip to step 13.
Issue a valid control sequence to the first installed single function binary output point using control code 0x04 (Latch
Off/NUL).
Verify the control operation in step 3 completes successfully.
If the DUT does not support the 0x41 (Pulse On/Close) control code for single function binary output points at this index
skip to step 16.
Issue a valid control sequence to the first installed single function binary output point using control code 0x41 (Pulse
On/Close).
Verify the control operation in step 3 completes successfully.
If the DUT does not support the 0x81 (Pulse On/Trip) control code for single function binary output points at this index
skip to the next section.
Issue a valid control sequence to the first installed single function binary output point using control code 0x81 (Pulse
On/Trip).
Verify the control operation in step 3 completes successfully.
8.3 Analog Output Status
The Analog Output Status object represents the actual value of an analog output or software point and the associated status
reported by an 8-bit flag field (repeated here for convenience):
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Flag Bit
0
1
2
3
4
5
6
7
Value
ONLINE - 0=off-line, 1= on-line
RESTART - 0=normal, 1= restart
COMMUNCATION LOST - 0=normal, 1=lost
REMOTE FORCED DATA - 0=normal, 1=forced
LOCAL FORCED DATA - 0=normal, 1=forced
0
0
0
Table 8-2
8.3.1 Desired Behavior
•
•
•
If the device supports analog outputs the device must respond to an analog output read request with an analog output
object (object 40 variation 2) using qualifier 0x00 or 0x01.
If the device does not support analog outputs the device must respond to an analog output read request with a Null
Response or an Error Response with IIN2-1 or IIN2-2 set.
The value returned in the Analog Output Status must reflect the value written to the corresponding Analog Output point
within the tolerances specified by the manufacturer.
8.3.2 Test Procedure
1.
2.
3.
4.
5.
6.
Issue a Direct Operate to Object 41 Variation 2 to an installed point using 16 bit indexing (qualifier 0x28) and an
appropriate value.
Issue a request for Object 40 Variation 0 using the all data qualifier 0x06.
If the device supports Analog Outputs verify that the DUT responds with an Analog Output Status object (object 40
Variation 2).
Verify that the data is reported using either 8 bit start/stop indexing (qualifier 0x00) or 16 bit start/stop indexing
(qualifier 0x01).
If the device does not support Analog Outputs verify that the DUT responds with a Null Response. The device can
optionally return an Error Response with IIN2-1or IIN2-2 set.
Verify that the value returned in the Analog Output Status object reflects the value sent in step 1 within the tolerances
specified by the manufacturer.
8.4 Analog Outputs
§ If a device supports analog outputs, it is required to be configurable to support all three modes of operation, namely Select
Before Operate, Direct Operate, and Direct Operate no Acknowledgment. A device may be configurable to disable any subset
of the modes. If a device has been configured to reject a particular mode, it must return a control status value of 4 (control
operation not supported for this point).
It is the hosts’ responsibility to determine the appropriate analog output mechanism. It is also the hosts’ responsibility to
perform select before operate control when it is unacceptable to have the analog output point operate more than once. This is
typically a configuration item in the host and is the responsibility of the end user to configure properly.
It is the outstations’ responsibility to perform the analog output operation if a correct control dialog has been issued from the
host.
If the DUT is configurable in a manner such that points can be uninstalled or disabled, the device must be configured with at
least one Analog Output point installed or enabled before proceeding with the test procedure.
8.4.1 Select Before Operate
The host first initiates the select portion of the dialog. The outstation then echoes the exact analog output request byte for
byte to the host. Note that the encapsulation information need not match, but that the object, variation, qualifier, and all object
data must match exactly. The host then sends the execute portion of the dialog. The object, variation, qualifier, and all object
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data must match exactly byte for byte the data sent in the select message. If the execute message matches the select message
byte for byte and it is received within the configured acceptable delay between select and execute, the outstation operates the
analog output point.
8.4.1.1 Desired Behavior
The following behavior assumes that the device does not support analog output operations:
• If the device does not support analog outputs it must respond to a select with an Error Response setting IIN2-1.
• An Error Response with IIN2-2 set is an invalid response.
• No further testing in this section is necessary.
The following behavior assumes that the device supports analog output operations:
• The maximum select to execute delay time must be specified in the Device Profile Document.
• The DUT responds to matching select and execute requests by echoing each request with the status field set to 0. The
specified analog output operates.
• The DUT responds to selecting an uninstalled analog output point by returning an error response with IIN2-2 set and a
status code of 4. The analog output point does not operate.
• The DUT responds to executing an installed analog output point after the configured acceptable select to execute delay
by echoing the execute and setting the status field to 1[Execute received after timeout]. The analog output does not
operate.
• The DUT responds to a non-matching execute with a status field of 2 [No previous matching select] and does not operate
the analog output under the following conditions:
• No prior select issued.
• Value does not match.
• The DUT operates various selected analog output points.
• The DUT supports 8 and 16 bit point indexing.
The following assumes that the device supports analog output operations and were added as a result of Technical Bulletin
TB2000-002 (Control Retries):
• The DUT must accept retries on the select portion of the analog output dialog that increment the application sequence
number between retries. In this case the select-to-operate timer must be restarted after reception of each select.
• The DUT must accept retries on the select portion of the analog output dialog that do not increment the application
sequence number between retries. In this case the select-to-operate timer must remain unaltered by the reception of each
additional select.
• The DUT must reject any operate that does not
• contain a application layer sequence number that is exactly one greater (modulo 16) than the previously accepted
select.
• match the object portion of the select message byte for byte, excluding the application header.
• The DUT must accept retries on the operate portion of the analog output dialog that does not increment the application
sequence number between retries. The DUT must echo the operate command but must not operate the analog output
more than once.
The following behavior assumes that the device does support analog output operations, however there are no analog output
points installed/enabled:
• If the device does not have any analog outputs installed, it must respond to a select with an Error Response setting IIN21 or IIN2-2.
8.4.1.2 Test Procedure
8.4.1.2.1 Analog Output, SBO, 0x28
1.
Issue a select using Object 41 Variation 2 to an installed point using 16 bit indexing (qualifier 0x28) and an appropriate
value.
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2.
3.
4.
5.
6.
If the device does not support analog outputs verify that the DUT responds with an Error Response with IIN2-1 set. End
testing of Analog Outputs.
Verify that the DUT responds by echoing the select message exactly.
Immediately issue a matching execute.
Verify that the DUT echoes the execute.
Verify that the selected analog output operates.
8.4.1.2.2 Analog Output, SBO, 0x17
1.
2.
3.
4.
5.
Issue a select using Object 41 Variation 2 to a different point using 8 bit indexing (qualifier 0x17) and an appropriate
value.
If the device does support analog outputs, verify that the DUT responds by echoing the select message exactly.
Immediately issue a matching execute.
Verify that the DUT echoes the execute.
Verify that the selected analog output operates.
8.4.1.2.3 Analog Output, SBO, to Uninstalled Point
1.
2.
3.
Issue a select using Object 41 Variation 2 to an uninstalled point using 16 bit indexing (qualifier 0x28) and an
appropriate value.
Verify that the DUT responds by returning an error response with IIN2-2 set and a status code of 4.
If an analog output is observed to operate, the test fails.
8.4.1.2.4 Analog Output, SBO, Execute Issued After Time-out
1.
2.
3.
4.
5.
Issue a select using Object 41 Variation 2 to an installed point using 8 bit indexing (qualifier 0x17) and an appropriate
value.
Verify that the DUT responds by echoing the select message exactly.
Wait 1 second past the configured maximum select to execute delay time.
Issue a matching execute and verify that the DUT echoes the execute with the status field set to 1 [Execute received after
timeout].
If an analog output is observed to operate, the test fails.
8.4.1.2.5 Analog Output, SBO, Execute Value does not match Select Value
1.
2.
3.
4.
5.
Issue a select using Object 41 Variation 2 to an installed point using 8 bit indexing (qualifier 0x17) and an appropriate
value.
Verify that the DUT responds by echoing the select message exactly.
Immediately issue an execute to Object 41 Variation 2 to an installed point using 8 bit indexing (qualifier 0x17) and the
same value incremented by 1.
Verify that the DUT echoes the execute with the status field set to 2 [No previous matching select].
If an analog output is observed to operate, the test fails.
8.4.1.2.6 Analog Output, SBO, Select 0x28, Execute 0x17
1.
2.
3.
4.
5.
Issue a select using Object 41 Variation 2 to an installed point using 16 bit indexing (qualifier 0x28) and an appropriate
value.
Verify that the DUT responds by echoing the select message exactly.
Immediately issue an execute to Object 41 Variation 2 to an installed point using 8 bit indexing (qualifier 0x17) and the
same value as the previous select.
Verify that the DUT echoes the execute with the control status field set to 2 [No previous matching select].
If an analog output is observed to operate, the test fails.
8.4.1.2.7 Analog Output, SBO, Configurable Device
1.
2.
3.
If the device is not configurable in a manner such that analog output points can be uninstalled or disabled, skip this
section.
Configure the DUT such that all Analog Output points are uninstalled or disabled.
Issue a select using Object 41 Variation 2 to point 0 using 16 bit indexing (qualifier 0x28) and an appropriate value.
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4.
5.
Verify that the DUT responds by returning an error response with IIN2-1 or IIN2-2 set.
If an analog output is observed to operate, the test fails.
8.4.1.2.8 Analog Output, SBO, Same Sequence Number Select Retries
1.
2.
3.
4.
5.
6.
7.
8.
If the DUT does not have installed analog output points, skip this section.
Issue a valid select to an installed analog output point.
Verify that the DUT echoes the object portion of the select byte for byte.
Issue the select again using the same application layer sequence number.
Verify that the DUT echoes the object portion of the select byte for byte.
Issue a valid operate, incrementing the sequence number by 1 modulo 16.
Verify that the DUT echoes the object portion of the operate byte for byte.
Verify that the DUT operates the analog output.
8.4.1.2.9 Analog Output, SBO, Incrementing Sequence Number Select Retries
1.
2.
3.
4.
5.
6.
7.
8.
If the DUT does not have installed analog output points, skip this section.
Issue a valid select to an installed analog output point.
Verify that the DUT echoes the object portion of the select byte for byte.
Issue the select again incrementing the application layer sequence number by 1 modulo 16.
Verify that the DUT echoes the object portion of the select byte for byte.
Issue a valid operate, incrementing the sequence number by 1 modulo 16.
Verify that the DUT echoes the object portion of the operate byte for byte.
Verify that the DUT operates the analog output.
8.4.1.2.10 Analog Output, SBO, Same Sequence Number Operate Retries
1.
2.
3.
4.
5.
6.
7.
8.
9.
If the DUT does not have installed analog output points, skip this section.
Issue a valid select to an installed analog output point.
Verify that the DUT echoes the object portion of the select byte for byte.
Issue a valid operate, incrementing the sequence number by 1 modulo 16.
Verify that the DUT echoes the object portion of the operate byte for byte.
Verify that the DUT operates the analog output.
Issue the operate again using the same application layer sequence number.
Verify that the DUT echoes the object portion of the operate byte for byte.
Verify that the DUT does not operate the analog output.
8.4.1.2.11 Analog Output, SBO, Incrementing Sequence Number Operate Retries
1.
2.
3.
4.
5.
6.
7.
8.
9.
If the DUT does not have installed analog output points, skip this section.
Issue a valid select to an installed analog output point.
Verify that the DUT echoes the object portion of the select byte for byte.
Issue a valid operate, incrementing the sequence number by 1 modulo 16.
Verify that the DUT echoes the object portion of the operate byte for byte.
Verify that the DUT operates the analog output.
Issue the operate again, incrementing the sequence number by 1 modulo 16.
Verify that the DUT echoes the object portion of the operate byte for byte with a status code value of 2 (NO
MATCHING SELECT).
Verify that the DUT does not operate the analog output.
8.4.1.2.12 Analog Output, SBO, Sequence number checking
1.
2.
3.
4.
5.
If the DUT does not have installed analog output points, skip this section.
Issue a valid select to an installed analog output point.
Verify that the DUT echoes the object portion of the select byte for byte.
Issue a valid operate, incrementing the sequence number by anything but 1 modulo 16.
Verify that the DUT echoes the object portion of the operate byte for byte with a status code value of 2 (NO
MATCHING SELECT).
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6.
7.
8.
9.
Verify that the DUT does not operate the analog output.
Issue a valid operate, incrementing the select sequence number by 1 modulo 16 to make sure the mismatched operate
cleared the previous select.
Verify that the DUT echoes the object portion of the operate byte for byte with a status code value of 2 (NO
MATCHING SELECT).
Verify that the DUT does not operate the analog output.
8.4.2 Direct Operate with Acknowledge
8.4.2.1 Desired Behavior
The following assumes that the device does not support analog output operations:
• If the device does not support analog outputs, it must respond to a direct operate with an Error Response setting IIN2-1.
• No further testing in this section is necessary.
The following assumes that the device supports analog output operations:
• The DUT responds to a Direct Operate to an installed analog output point echoing the direct operate and setting the
status field to 0. The specified analog output operates.
• The DUT responds to a Direct Operate to an uninstalled analog output point by returning an Error Response with IIN2-2
set and a status code of 4. No analog outputs shall be observed to operate.
• The DUT operates various analog output points.
The following assumes that the device does support analog output operations, however there are no analog output points
installed/enabled:
• If the device does not have any analog outputs installed, it must respond to a direct operate with an Error Response
setting IIN2-1 or IIN2-2.
8.4.2.2 Test Procedure
8.4.2.2.1 Analog Output, Direct Operate
1.
2.
3.
4.
Issue a Direct Operate to Object 41 Variation 2 to an installed point using 8 bit indexing (qualifier 0x17) and an
appropriate value.
If the device does not support analog output verify that the DUT responds with an Error Response with IIN2-1 set and
end testing of this section.
If the device does support analog outputs verify that the DUT responds by echoing the direct operate message exactly
with status field of 0.
Verify that the specified analog output operates.
8.4.2.2.2 Analog Output, Direct Operate, to Uninstalled Point
1.
2.
3.
Issue a Direct Operate to Object 41 Variation 2 to an uninstalled point using 16 bit indexing (qualifier 0x28) and an
appropriate value.
Verify that the DUT responds by return an Error Response with IIN2-2 set and a status code of 4.
If an analog output is observed to operate, the test fails.
8.4.2.2.3
1.
2.
3.
4.
5.
Analog Output, Direct Operate, Configurable Device
If the device is not configurable in a manner such that analog output points can be uninstalled or disabled, end testing of
Analog Output, Direct Operate.
Configure the DUT such that all Analog Output points are uninstalled or disabled.
Issue a direct operate to Object 41 Variation 2 to point 0 using 16 bit indexing (qualifier 0x28) and an appropriate value.
Verify that the DUT responds by returning an error response with IIN2-1 or IIN2-2 set.
If an analog output is observed to operate, the test fails.
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8.4.3 Direct Operate, No Acknowledge
8.4.3.1 Desired Behavior
•
•
The DUT must not respond in any way to the direct operate no acknowledge.
If the device supports analog outputs and the operate message is correct then the analog output point must operate.
8.4.3.2 Test Procedure
8.4.3.2.1 Analog Output, Direct Operate, No Acknowledge
1.
2.
3.
4.
Issue a Direct Operate No Acknowledge using Object 41 Variation 2 to an installed point using 8 bit indexing (qualifier
0x17) and an appropriate value.
Verify that the DUT does not respond.
If the device does support analog outputs, end testing of this section.
If the device does support analog outputs, verify that the proper analog output point operates.
8.4.3.2.2 Analog Output, Direct Operate, No Acknowledge, to an Uninstalled Point
1.
2.
3.
Issue a Direct Operate No Acknowledge using Object 41 Variation 2 to an uninstalled point using 16 bit indexing
(qualifier 0x28) and an appropriate value.
Verify that the DUT does not respond.
If an analog output is observed to operate, the test fails.
8.4.3.2.3
1.
2.
3.
4.
5.
Analog Output, Direct Operate, No Acknowledge, Configurable Device
If the device is not configurable in a manner such that control points can be uninstalled or disabled, end testing of Analog
Output, Direct Operate, No Acknowledge.
Configure the DUT such that all Analog Output points are uninstalled or disabled.
Issue a Direct Operate No Acknowledge using Object 41 Variation 2 to point 0 using 16 bit indexing (qualifier 0x28)
using a control code supported by the device and an appropriate on time/off time.
Verify that the DUT does not respond.
If an analog output is observed to operate, the test fails.
8.4.4 Multiple Object Requests
8.4.4.1 Desired Behavior
•
•
The DUT must parse requests for all writes within a single frame
Up to a full frame of request operations must be supported
The following assumes that the device supports analog output operations and were added as a result of Technical Bulletin
TB2001-001 (Multiple Control Object and Status Codes):
• The DUT responds to requests having more points than are supported in a single message with a status code of 8 for
at least the first point that is beyond the point count limit.
• The DUT responds to a select to an uninstalled analog output point by returning an error response with IIN2-2 set
and a status code of 4.
8.4.4.2 Test Procedure
1.
2.
Review the device’s profile document to understand how many analog output points are supported in a single request. If
this number is one, skip to step 7.
Determine the number of installed points that can be successfully controlled in a single request. This number shall be the
smaller of:
• The number of controls supported in a single request
• The number of installed control points
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3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
14.
• Sixteen
In a single request, issue a select to the above number of points using Object 41, Variation 2 and 16-bit indexing
(qualifier 0x28), a control code supported by the device, and a value supported by the device
Verify that the DUT response has none of IIN2-0, IIN2-1, or IIN2-2 set and that each object returns a status code of 0.
Immediately issue a matching execute.
Verify that the DUT response has none of IIN2-0, IIN2-1, or IIN2-2 set and that each object returns a status code of 0.
Verify that each of the selected analog outputs occurred. . Note outputs may occur simultaneously or sequentially one
after the other.
If the number of control objects supported in a single request is greater than or equal to either:
• The number of control objects that fit into a single frame or
• The number of installed control points
skip to step 13.
In a single request, issue a select to at least one more point than is supported in a single request, each point having a
different index but otherwise able to be outputted, using Object 41, Variation 2 and 16-bit indexing (qualifier 0x28) and
an appropriate value.
Verify that the DUT response has none of IIN2-0, IIN2-1, or IIN2-2 set, that each object except the last returns a status
code of 0, and the last object returns a status code of 8.
If the DUT does not support direct operate, skip to step 13.
In a single request, issue a direct operate command to at least one more point than is supported in a single request, each
point having a different index but otherwise able to be outputted, using Object 41, Variation 2 and 16-bit indexing
(qualifier 0x28) and an appropriate value.
Verify that the DUT response has none of IIN2-0, IIN2-1, or IIN2-2 set, that each object except the last returns a status
code of 0 and the last object returns a status code of 8. Verify that all except the last analog output point outputted the
new value(s).
In a single request, issue a select to one installed analog output point and to one point that is not installed using Object
41, Variation 2 and 16-bit indexing (qualifier 0x28) and an appropriate value. The installed point should be the first
object in the request.
Verify that the DUT response has IIN2-2 bit set, that the status code returned for the installed point is 0 and the status
code returned for the non-installed point is 4.
8.5 Class Data
8.5.1 Class 0
This request is used to read all static data from a device. The device must respond with the current state of its data when this
object is requested.
§ Any device that generates more than one link layer frame in response to a Class 0 Poll must support report-by-exception on
all points. It is highly recommended that devices perform report by exception processing internally and respond to class polls
with event data as defined in section 3.4. This allows efficient use of bandwidth. When no events are pending the device
responds with the Null Response.
Acceptable object variations and qualifier combinations included in a device response are specified in the following table.
Numbers preceded by 0x are in hex.
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Single-Bit Binary Input
Binary Input with Status
Binary Output Status
32-Bit Binary Counter
16-Bit Binary Counter
32-Bit Delta Counter
16-Bit Delta Counter
32-Bit Binary Counter w/o Flag
16-Bit Binary Counter w/o Flag
32-Bit Delta Counter w/o Flag
16-Bit Delta Counter w/o Flag
32-Bit Analog Input
16-Bit Analog Input
32-Bit Analog Input w/o Flag
16-Bit Analog Input w/o Flag
16-Bit Analog Output Status
Table 8-3
Object
1
1
10
20
20
20
20
20
20
20
20
30
30
30
30
40
Variation
1
2
2
1
2
3
4
5
6
7
8
1
2
3
4
2
Qualifier
0x00,0x01
0x00,0x01
0x00,0x01
0x00,0x01
0x00,0x01
0x00,0x01
0x00,0x01
0x00,0x01
0x00,0x01
0x00,0x01
0x00,0x01
0x00,0x01
0x00,0x01
0x00,0x01
0x00,0x01
0x00,0x01
8.5.1.1 Desired Behavior
•
Device responds to a Class 0 poll with the current state of all data.
8.5.1.2 Test Procedure
1.
2.
3.
Issue a request for Object 60 Variation 1 using the all data qualifier 0x06.
Verify that the device responds with the current state of its inputs using only the object, variation and qualifier variations
specified in table 8-3.
Verify that flag behavior complies with Section 2, Note #5.
8.5.2 Class 1
This request is used to read change or event data from a device. The device must respond with events that have occurred
since the last poll/confirm sequence. If the response is not null, verify that the device requests an application layer confirm.
If the response is null, the request for the application layer confirm is optional and may be eliminated to reduce bandwidth.
Points can be assigned to a class by configuration and through the protocol. Neither is required for compliance. The minimum
level of compliance is for the device to respond with a Null Response.
§ Any device that generates more than one link layer frame in response to a Class 0 Poll must support report-by-exception on
all points. It is highly recommended that devices perform report by exception processing internally and respond to class polls
with event data as defined in section 3.4. This allows efficient use of bandwidth. When no events are pending the device
responds with the Null Response.
If a device can be configured to generate Application Layer retries, this feature must be disabled for all tests in this section
unless otherwise specified.
Acceptable object variations and qualifier combinations included in a device response are specified in the following table.
Numbers preceded by 0x are in hex.
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Binary Input Change w/o Time
Binary Input Change with Time
Binary Input Change with Relative Time
32-Bit Counter Change Event w/o Time
16-Bit Counter Change Event w/o Time
32-Bit Delta Counter Change Event w/o Time
16-Bit Delta Counter Change Event w/o Time
32-Bit Analog Change Event w/o Time
16-Bit Analog Change Event w/o Time
Time and Date CTO*
Unsynchronized Time and Date CTO*
Table 8-4
Object
2
2
2
22
22
22
22
32
32
51
51
Variation
1
2
3†
1
2
3
4
1
2
1
2
Qualifier
0x17,0x28
0x17,0x28
0x17,0x28
0x17,0x28
0x17,0x28
0x17,0x28
0x17,0x28
0x17,0x28
0x17,0x28
0x07
0x07
† Note: Use of the Binary Change with Relative Time Object (Object 2, Variation3) requires that a Common Time of
Occurrence Object (Object 51, Variation01 or 02) precede it in the same APDU. This behavior must be verified in any
response that contains a Binary Change with Relative Time Object. Binary Input changes more than 0xFFFF milliseconds
apart must have a second CTO Object.
* Note: Common Time of Occurrence
8.5.2.1 Desired Behavior
•
•
•
•
§ The device must respond with all of its change events when polled with the all data qualifier (0x06).
When polled with the limit data qualifiers (0x07 and 0x08), the device must respond with a quantity of its change events
no greater than specified in the request.
The device must request an application layer confirm for all responses that contain event data. Note: Application layer
confirms are always sent by the Master upon request from the Slave unless otherwise noted in this section.
The response point ordering shall be prioritized by time (oldest first).
Note: A device is not required to return event data in any particular class.
8.5.2.2 Test Procedure
8.5.2.2.1 Class 1 Data, 0x06
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
14.
Issue a request for Object 60 Variation 2 using the all data qualifier 0x06.
§ Verify that if the DUT responds to a class 0 poll with more than one link layer frame it also performs report-by
exception processing.
If the DUT does not support Class 1 events, verify that it responds with a Null Response. No further testing is required in
this section.
If the DUT does support Class 1 events, verify that the device responds with all the event data in its event buffers or
responds with a Null Response.
If requested, issue an application layer confirm to empty the device of pending events.
Generate known Class 1 event data.
Issue another request for Object 60 Variation 2 using the all data qualifier 0x06.
Verify that the device responds with all the Class 1 event data generated in a single response.
Verify that only objects in table 8-4 are returned and that the events are in time order (oldest first).
Verify that the data is reported using either 8 bit indexing (qualifier 0x17) or 16 bit indexing (qualifier 0x28).
Verify that flag behavior complies with Section 2, Note #5.
§ Verify that the device requests an application layer confirm.
Issue another request for Object 60 Variation 2 using the all data qualifier 0x06.
Verify that the DUT responds with a Null Response.
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8.5.2.2.2 Class 1 Data, 0x07
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
14.
15.
Issue a request for Object 60 Variation 2 using the all data qualifier 0x06 to empty the device of pending events.
§ If the response is not Null, verify that the device requests an application layer confirm.
If requested, issue an application layer confirm to empty the device of pending events.
Generate several Class 1 events.
Issue a request for Object 60 Variation 2 using the limit data qualifier 0x07 requesting some changes.
Verify that the device responds with the requested Class 1 events in a single response.
Verify that only objects in table 8-4 are returned.
Verify that the data is reported using either 8 bit indexing (qualifier 0x17) or 16 bit indexing (qualifier 0x28).
Verify that flag behavior complies with Section 2, Note #5.
§ Verify that the device requests an application layer confirm.
Issue a request for Object 60 Variation 2 using the limit data qualifier 0x07 requesting the remaining changes.
Verify that device responds with the remaining Class 1 events.
§ Verify that the device requests an application layer confirm.
Issue another request for Object 60 Variation 2 using the all data qualifier 0x06.
Verify that the DUT responds with a Null Response.
8.5.2.2.3 Class 1 Data, 0x08
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
14.
15.
Issue a request for Object 60 Variation 2 using the all data qualifier 0x06 to empty the device of pending events.
§ If the response is not Null, verify that the device requests an application layer confirm.
If requested, issue an application layer confirm to empty the device of pending events.
Generate several Class 1 events.
Issue a request for Object 60 Variation 2 using the limit data qualifier 0x08 requesting some changes.
Verify that the device responds with the requested Class 1 events in a single response.
Verify that only objects in table 8-4 are returned.
Verify that the data is reported using either 8 bit indexing (qualifier 0x17) or 16 bit indexing (qualifier 0x28).
Verify that flag behavior complies with Section 2, Note #5.
§ Verify that the device requests an application layer confirm.
Issue a request for Object 60 Variation 2 using the limit data qualifier 0x08 requesting the remaining changes.
Verify that device responds with the remaining Class 1 events.
§ Verify that the device requests an application layer confirm.
Issue another request for Object 60 Variation 2 using the all data qualifier 0x06.
Verify that the DUT responds with a Null Response.
8.5.2.2.4 § Class 1 Data Without Confirm
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
14.
15.
16.
17.
Issue a request for Object 60 Variation 2 using the all data qualifier 0x06.
§ If the response is not Null, verify that the device requests an application layer confirm.
If requested, issue an application layer confirm to empty the device of pending events.
Generate known Class 1 event data.
Issue a request for Object 60 Variation 2 using the all data qualifier 0x06.
Verify that the device responds with all the Class 1 event data.
Verify that only objects in table 8-4 are returned.
Verify that the data is reported using either 8 bit indexing (qualifier 0x17) or 16 bit indexing (qualifier 0x28).
Verify that flag behavior complies with Section 2, Note #5.
§ Verify that the device requests an application layer confirm.
Do not issue an application layer confirm to the device.
Wait for a period of time exceeding several of the Application Layer retry delays, if one exists.
Verify that the device has not retransmitted the previous Application Layer fragment.
Generate additional Class 1 event data.
Issue a request for Object 60 Variation 2 using the all data qualifier 0x06.
Verify that the device responds with the same Class 1 event data and the additional data generated in step 14.
§ Verify that the device requests an application layer confirm.
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18. Issue an application layer confirm to empty the device of pending events.
19. Issue a request for Object 60 Variation 2 using the all data qualifier 0x06.
20. Verify that the device responds with a Null Response.
8.5.3 Class 2
This request is used to read change or event data from a device. The device must respond with events that have occurred
since the last poll/confirm sequence. If the response is not null, verify that the device requests an application layer confirm.
If the response is null, the request for the application layer confirm is optional and may be eliminated to reduce bandwidth.
Points can be assigned to a class by configuration and through the protocol. Neither is required for compliance. The minimum
level of compliance is for the device to respond with a Null Response.
If a device can be configured to generate Application Layer retries, this feature must be disabled for all tests in this section
unless otherwise specified.
§ Any device that generates more than one link layer frame in response to a Class 0 Poll must support report-by-exception on
all points. It is highly recommended that devices perform report by exception processing internally and respond to class polls
with event data as defined in section 3.4. This allows efficient use of bandwidth. When no events are pending the device
responds with the Null Response.
8.5.3.1 Desired Behavior
•
•
•
•
§ The device must respond with all of its change events when polled with the all data qualifier (0x06).
When polled with the limit data qualifiers (0x07 and 0x08), the device must respond with a quantity of its change events
no greater than specified in the request.
The device must request an application layer confirm for all responses that contain event data. Note: Application layer
confirms are always sent by the Master upon request from the Slave unless otherwise noted in this section.
The response point ordering shall be prioritized by time (oldest first).
Note: A device is not required to return event data in any particular class.
8.5.3.2 Test Procedure
8.5.3.2.1 Class 2 Data, 0x06
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
14.
Issue a request for Object 60 Variation 3 using the all data qualifier 0x06.
§ Verify that if the DUT responds to a class 0 poll with more than one link layer frame it also performs report-by
exception processing.
If the DUT does not support Class 2 events, verify that it responds with a Null Response. No further testing is required in
this section.
If the DUT does support Class 2 events, verify that the device responds with all the event data in its event buffers or
responds with a Null Response.
If requested, issue an application layer confirm to empty the device of pending events.
Generate known Class 2 event data.
Issue another request for Object 60 Variation 3 using the all data qualifier 0x06.
Verify that the device responds with all the Class 2 event data generated in a single response.
Verify that only objects in table 8-4 are returned and that the events are in time order (oldest first).
Verify that the data is reported using either 8 bit indexing (qualifier 0x17) or 16 bit indexing (qualifier 0x28).
Verify that flag behavior complies with Section 2, Note #5.
§ Verify that the device requests an application layer confirm.
Issue another request for Object 60 Variation 3 using the all data qualifier 0x06.
Verify that the DUT responds with a Null Response.
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8.5.3.2.2 Class 2 Data, 0x07
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
14.
15.
Issue a request for Object 60 Variation 3 using the all data qualifier 0x06 to empty the device of pending events.
§ If the response is not Null, verify that the device requests an application layer confirm.
If requested, issue an application layer confirm to empty the device of pending events.
Generate several Class 2 events.
Issue a request for Object 60 Variation 3 using the limit data qualifier 0x07 requesting some changes.
Verify that the device responds with the requested Class 2 events in a single response.
Verify that only objects in table 8-4 are returned.
Verify that the data is reported using either 8 bit indexing (qualifier 0x17) or 16 bit indexing (qualifier 0x28).
Verify that flag behavior complies with Section 2, Note #5.
§ Verify that the device requests an application layer confirm.
Issue a request for Object 60 Variation 3 using the limit data qualifier 0x07 requesting the remaining changes.
Verify that device responds with the remaining Class 2 events.
§ Verify that the device requests an application layer confirm.
Issue another request for Object 60 Variation 3 using the all data qualifier 0x06.
Verify that the DUT responds with a Null Response.
8.5.3.2.3 Class 2 Data, 0x08
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
14.
15.
Issue a request for Object 60 Variation 3 using the all data qualifier 0x06 to empty the device of pending events.
§ If the response is not Null, verify that the device requests an application layer confirm.
If requested, issue an application layer confirm to empty the device of pending events.
Generate several Class 2 events.
Issue a request for Object 60 Variation 3 using the limit data qualifier 0x08 requesting some changes.
Verify that the device responds with the requested Class 2 events in a single response.
Verify that only objects in table 8-4 are returned.
Verify that the data is reported using either 8 bit indexing (qualifier 0x17) or 16 bit indexing (qualifier 0x28).
Verify that flag behavior complies with Section 2, Note #5.
§ Verify that the device requests an application layer confirm.
Issue a request for Object 60 Variation 3 using the limit data qualifier 0x08 requesting the remaining changes.
Verify that device responds with the remaining Class 2 events.
§ Verify that the device requests an application layer confirm.
Issue another request for Object 60 Variation 3 using the all data qualifier 0x06.
Verify that the DUT responds with a Null Response.
8.5.3.2.4 § Class 2 Data Without Confirm
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
14.
15.
16.
17.
Issue a request for Object 60 Variation 3 using the all data qualifier 0x06.
§ If the response is not Null, verify that the device requests an application layer confirm.
If requested, issue an application layer confirm to empty the device of pending events.
Generate known Class 2 event data.
Issue a request for Object 60 Variation 3 using the all data qualifier 0x06.
Verify that the device responds with all the Class 2 event data.
Verify that only objects in table 8-4 are returned.
Verify that the data is reported using either 8 bit indexing (qualifier 0x17) or 16 bit indexing (qualifier 0x28).
Verify that flag behavior complies with Section 2, Note #5.
§ Verify that the device requests an application layer confirm.
Do not issue an application layer confirm to the device.
Wait for a period of time exceeding several of the Application Layer retry delays, if one exists.
Verify that the device has not retransmitted the previous Application Layer fragment.
Generate additional Class 2 event data.
Issue a request for Object 60 Variation 3 using the all data qualifier 0x06.
Verify that the device responds with the same Class 2 event data and the additional data generated in step 14.
§ Verify that the device requests an application layer confirm.
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18. Issue an application layer confirm to empty the device of pending events.
19. Issue a request for Object 60 Variation 3 using the all data qualifier 0x06.
20. Verify that the device responds with a Null Response.
8.5.4 Class 3
This request is used to read change or event data from a device. The device must respond with events that have occurred
since the last poll/confirm sequence. If the response is not null, verify that the device requests an application layer confirm.
If the response is null, the request for the application layer confirm is optional and may be eliminated to reduce bandwidth.
Points can be assigned to a class by configuration and through the protocol. Neither is required for compliance. The minimum
level of compliance is for the device to respond with a Null Response.
If a device can be configured to generate Application Layer retries, this feature must be disabled for all tests in this section
unless otherwise specified.
§ Any device that generates more than one link layer frame in response to a Class 0 Poll must support report-by-exception on
all points. It is highly recommended that devices perform report by exception processing internally and respond to class polls
with event data as defined in section 3.4. This allows efficient use of bandwidth. When no events are pending the device
responds with the Null Response.
8.5.4.1 Desired Behavior
•
•
•
•
§ The device must respond with all of its change events when polled with the all data qualifier (0x06).
When polled with the limit data qualifiers (0x07 and 0x08), the device must respond with a quantity of its change events
no greater than specified in the request.
The device must request an application layer confirm for all responses that contain event data. Note: Application layer
confirms are always sent by the Master upon request from the Slave unless otherwise noted in this section.
The response point ordering shall be prioritized by time (oldest first).
Note: A device is not required to return event data in any particular class.
8.5.4.2 Test Procedure
8.5.4.2.1 Class 3 Data, 0x06
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
14.
Issue a request for Object 60 Variation 4 using the all data qualifier 0x06.
§ Verify that if the DUT responds to a class 0 poll with more than one link layer frame it also performs report-by
exception processing.
If the DUT does not support Class 3 events, verify that it responds with a Null Response. No further testing is required in
this section.
If the DUT does support Class 3 events, verify that the device responds with all the event data in its event buffers or
responds with a Null Response.
If requested, issue an application layer confirm to empty the device of pending events.
Generate known Class 3 event data.
Issue another request for Object 60 Variation 4 using the all data qualifier 0x06.
Verify that the device responds with all the Class 3 event data generated in a single response.
Verify that only objects in table 8-4 are returned and that the events are in time order (oldest first).
Verify that the data is reported using either 8 bit indexing (qualifier 0x17) or 16 bit indexing (qualifier 0x28).
Verify that flag behavior complies with Section 2, Note #5.
§ Verify that the device requests an application layer confirm.
Issue another request for Object 60 Variation 4 using the all data qualifier 0x06.
Verify that the DUT responds with a Null Response.
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8.5.4.2.2 Class 3 Data, 0x07
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
14.
15.
Issue a request for Object 60 Variation 4 using the all data qualifier 0x06 to empty the device of pending events.
§ If the response is not Null, verify that the device requests an application layer confirm.
If requested, issue an application layer confirm to empty the device of pending events.
Generate several Class 3 events.
Issue a request for Object 60 Variation 4 using the limit data qualifier 0x07 requesting some changes.
Verify that the device responds with the requested Class 3 events in a single response.
Verify that only objects in table 8-4 are returned.
Verify that the data is reported using either 8 bit indexing (qualifier 0x17) or 16 bit indexing (qualifier 0x28).
Verify that flag behavior complies with Section 2, Note #5.
§ Verify that the device requests an application layer confirm.
Issue a request for Object 60 Variation 4 using the limit data qualifier 0x07 requesting the remaining changes.
Verify that device responds with the remaining Class 3 events.
§ Verify that the device requests an application layer confirm.
Issue another request for Object 60 Variation 4 using the all data qualifier 0x06.
Verify that the DUT responds with a Null Response.
8.5.4.2.3 Class 3 Data, 0x08
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
14.
15.
Issue a request for Object 60 Variation 4 using the all data qualifier 0x06 to empty the device of pending events.
§ If the response is not Null, verify that the device requests an application layer confirm.
If requested, issue an application layer confirm to empty the device of pending events.
Generate several Class 3 events.
Issue a request for Object 60 Variation 4 using the limit data qualifier 0x08 requesting some changes.
Verify that the device responds with the requested Class 3 events in a single response.
Verify that only objects in table 8-4 are returned.
Verify that the data is reported using either 8 bit indexing (qualifier 0x17) or 16 bit indexing (qualifier 0x28).
Verify that flag behavior complies with Section 2, Note #5.
§ Verify that the device requests an application layer confirm.
Issue a request for Object 60 Variation 4 using the limit data qualifier 0x08 requesting the remaining changes.
Verify that device responds with the remaining Class 3 events.
§ Verify that the device requests an application layer confirm.
Issue another request for Object 60 Variation 4 using the all data qualifier 0x06.
Verify that the DUT responds with a Null Response.
8.5.4.2.4 § Class 3 Data Without Confirm
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
14.
15.
16.
17.
Issue a request for Object 60 Variation 4 using the all data qualifier 0x06.
§ If the response is not Null, verify that the device requests an application layer confirm.
If requested, issue an application layer confirm to empty the device of pending events.
Generate known Class 3 event data.
Issue a request for Object 60 Variation 4 using the all data qualifier 0x06.
Verify that the device responds with all the Class 1 event data.
Verify that only objects in table 8-4 are returned.
Verify that the data is reported using either 8 bit indexing (qualifier 0x17) or 16 bit indexing (qualifier 0x28).
Verify that flag behavior complies with Section 2, Note #5.
§ Verify that the device requests an application layer confirm.
Do not issue an application layer confirm to the device.
Wait for a period of time exceeding several of the Application Layer retry delays, if one exists.
Verify that the device has not retransmitted the previous Application Layer fragment.
Generate additional Class 3 event data.
Issue a request for Object 60 Variation 4 using the all data qualifier 0x06.
Verify that the device responds with the same Class 1 event data and the additional data generated in step 14.
§ Verify that the device requests an application layer confirm.
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18. Issue an application layer confirm to empty the device of pending events.
19. Issue a request for Object 60 Variation 4 using the all data qualifier 0x06.
20. Verify that the device responds with a Null Response.
8.5.5 Multiple Object Request
This test verifies that the device can parse multiple object requests.
Note: If Binary Inputs can be configured in more than one class, they must be configured for at least one of each class for
these tests.
8.5.5.1 Desired Behavior
•
•
•
The device must respond to a multiple object request in a single response.
For binary points, all events reported within a single application fragment will be sent in the chronological order of
occurrence of those events (oldest first).
§ When a device generates multiple analog or counter events for the same point, all events for the same point will be sent
in the chronological order of occurrence of those events (oldest first).
8.5.5.2 Test Procedure
8.5.5.2.1 Multiple Object Request, Class 1, 2, and 3
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
Issue a request for Object 60 Variations 2,3, and 4 using the all data qualifier 0x06.
§ If the response is not Null, verify that the device requests an application layer confirm.
If requested, issue an application layer confirm to empty the device of pending events.
Generate known event data that includes events from all three classes.
Issue a request for Object 60 Variations 2,3, and 4 using the all data qualifier 0x06.
Verify that the device responds with all the event data as described in the Desired Behavior.
Verify that only objects in table 8-4 are returned and that the events are in time order (oldest first).
Verify that the data is reported using either 8 bit indexing (qualifier 0x17) or 16 bit indexing (qualifier 0x28).
Verify that flag behavior complies with Section 2, Note #5.
§ Verify that the device requests an application layer confirm.
Issue an application layer confirm to empty the device of pending events.
8.5.5.2.2 Multiple Object Request, Class 1, 2, 3, and 0
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
Issue a request for Object 60 Variations 2,3, and 4 using the all data qualifier 0x06.
§ If the response is not Null, verify that the device requests an application layer confirm.
If requested, issue an application layer confirm to empty the device of pending events.
Generate known event data that includes events from classes 1, 2, and 3.
Issue a request for Object 60 Variations 2,3,4, and 1 using the all data qualifier 0x06.
Verify that the device responds with all the event data as described in the Desired Behavior.
Verify that all static data is returned after all event data in the same response.
Verify that the response has the same application sequence number as the request. If the request generates multiple
application fragments verify that the application sequence number of each subsequent fragment increments by 1 modulo
16.
Verify that only objects in table 8-4 are returned.
Verify that the data is reported using either 8 bit indexing (qualifier 0x17) or 16 bit indexing (qualifier 0x28) for event
data and 8 bit start/stop indexing (qualifier 0x00) or 16 bit start/stop indexing (qualifier 0x01) for static data.
Verify that flag behavior complies with Section 2, Note #5.
§ Verify that the device requests an application layer confirm.
Issue an application layer confirm to empty the device of pending events.
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8.5.6 Class Assignment Verification
8.5.6.1 Desired Behavior
•
•
•
The device must respond to a request for Class 1 events with only Class 1 events.
The device must respond to a request for Class 2 events with only Class 2 events.
The device must respond to a request for Class 3 events with only Class 3 events.
8.5.6.2 Test Procedure
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
14.
15.
16.
17.
18.
19.
20.
21.
22.
23.
24.
25.
26.
Issue a request for Object 60 Variations 2,3 and 4 using the all data qualifier 0x06 to empty the device of pending events.
Verify that only objects in table 8-4 are returned.
§ If the response is not Null, verify that the device requests an application layer confirm.
Generate some Class 1 events.
Generate some Class 2 events.
Generate some Class 3 events.
Issue a request for Object 60 Variation 2 using the all data qualifier 0x06.
Verify that the device responds with only Class 1 events in a single response.
Verify that only objects in table 8-4 are returned.
§ Verify that the device requests an application layer confirm.
Issue a request for Object 60 Variation 2 using the all data qualifier 0x06.
Verify that the device responds with a Null Response.
Issue a request for Object 60 Variation 3 using the all data qualifier 0x06.
Verify that the device responds with only Class 2 events in a single response.
Verify that only objects in table 8-4 are returned.
§ Verify that the device requests an application layer confirm.
Issue a request for Object 60 Variation 3 using the all data qualifier 0x06.
Verify that the device responds with a Null Response.
Issue a request for Object 60 Variation 4 using the all data qualifier 0x06.
Verify that the device responds with only Class 3 events in a single response.
Verify that only objects in table 8-4 are returned.
§ Verify that the device requests an application layer confirm.
Issue a request for Object 60 Variation 4 using the all data qualifier 0x06.
Verify that the device responds with a Null Response.
Issue a request for Object 60 Variations 2,3 and 4 using the all data qualifier 0x06.
Verify that the device responds with a Null Response.
8.6 Indications
The Internal Indications is an information element used to convey internal states and diagnostic results of a device. If a
specific indication is not supported it must be reported as de-asserted (0) in all cases.
8.6.1 Restart
The Restart Bit of the Internal Indications field is set to 1 when the user application at the device restarts, i.e. a device's input
power is cycled. This bit is cleared when the master station writes a 0 into this location.
8.6.1.1 Desired Behavior
•
•
The DUT, after a power cycle, must set IIN1-7.
The host can clear this bit by writing to the Internal Indications Object (Object 80, Variation 01).
8.6.1.2 Test Procedure
1.
2.
3.
Cycle the power to the DUT.
Issue a request for Object 60 Variation 2.
Verify that the device responds with IIN1-7 set indicating that the device has been restarted.
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4.
5.
Issue a Write to Object 80 Variation 1 using the qualifier 0x00. Use a start index of 7 and a stop index of 7, followed by
the value 0.
Verify that the device responds with a Null Response and that IIN1-7 is cleared.
8.6.2 Bad Function
8.6.2.1 Desired Behavior
•
•
If a device receives a message containing an unsupported function code it must return an Error Response with IIN2-0 set.
After a device has issued a message containing a valid function code, the response shall have no Error IIN bits set.
8.6.2.2 Test Procedure
1.
2.
3.
4.
Issue a request for Object 60 Variation 1, Qualifier 0x06, using a Function Code of 0x70.
Verify that the device responds with an Error Response with IIN2-0 set indicating that the device has received a message
containing a bad function code.
Issue a request for Object 60 Variation 1, Qualifier 0x06, using a Function Code of 0x01.
Verify that the device responds with none of the Error IIN bits set.
8.6.3 Object Unknown
8.6.3.1 Desired Behavior
•
•
If a device receives a message containing an unknown object, it must return an Error Response with IIN2-1 set.
After a device has issued a message containing a valid function code, the response shall have no Error IIN bits set.
8.6.3.2 Test Procedure
1.
2.
3.
4.
Issue a request for Object 0 Variation 0, Function Code 0x01.
Verify that the device responds with an Error Response with IIN2-1 set indicating that the device has received a message
containing an unknown Object code.
Issue a request for Object 60 Variation 1.
Verify that the device responds with none of the Error IIN bits set.
8.6.4 Local
8.6.4.1 Desired Behavior
•
If the device supports control outputs and supports placing them in a local or disabled stated then it must set IIN1-5
whenever some or all of the control outputs are in the Local or Disabled state.
8.6.4.2 Test Procedure for Devices with Global Remote Supervisory Control
1.
2.
3.
4.
5.
6.
7.
If the DUT does not support placing its binary outputs in a local state no further testing is required in this section.
If the DUT supports a global feature for enabling or disabling remote supervisory control, ensure that this is set to the
“Enabled” or “Remote” mode.
Issue a request for Object 10 Variation 0 using the all data qualifier 0x06.
Verify that the device responds with a valid message and that IIN1-5 is cleared.
Change the DUT’s global switch to the “Disabled” or “Local” mode.
Issue a request for Object 10 Variation 0 using the all data qualifier 0x06.
Verify that the device responds with a valid message and that IIN1-5 is set.
8.6.4.3 Test Procedure for Devices with Individual Remote Supervisory Control
1.
2.
If the DUT does not support placing its binary outputs in a local state, no further testing is required in this section.
If the device allows for individual control point remote supervisory control, all points should be set to the “Enabled” or
“Remote” mode.
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3.
4.
5.
6.
7.
Issue a request for Object 10 Variation 0 using the all data qualifier 0x06.
Verify that the device responds with a valid message. No binary output status bits should be set.
Change a single remote supervisory control switch to the “Disabled” or “Local” mode.
Issue a request for Object 10 Variation 0 using the all data qualifier 0x06.
Verify that the device responds with a valid message and that the appropriate binary output status bit is set.
8.6.5 Broadcast Address and All Stations Indication
8.6.5.1 Desired Behavior
•
•
•
•
•
•
The DUT must execute any request sent to the broadcast address
§ The DUT must not respond in any way to any request sent to the broadcast address
The DUT must set the All Stations Internal Indication (IIN1-0) in the next response it transmits
The DUT must clear the All Stations Internal Indication on the next response following the one in which it was set.
§ Messages sent to address 0xFFFE require that the IIN1-0 bit must be returned with the application layer request for
confirmation bit (Application Control, bit 5) set. IIN1-0 may not be cleared in the slave until the confirmation is
received.
§ Messages sent to address 0xFFFD request the IIN1-0 bit to be returned with the application layer request for
confirmation bit (Application Control, bit 5) suppressed. IIN1-0 will be cleared in the slave upon transmitting the first
response from the slave. Note: IIN1-0 may be reported in conjunction with responses to requests that otherwise require
confirmation, or with an unsolicited event report, and since these requests/responses otherwise require confirmation, the
confirmation will not be suppressed even though the message is sent with IIN1-0 set. Thus the use of the FFFD broadcast
address implies that confirmation requests in responses sent with the IIN1-0 set should be suppressed, but that the
confirmation may be requested if required by the details of the response being issued.
8.6.5.2 § Test Procedure
1.
2.
3.
4.
5.
Cycle the power to the DUT.
Issue a link reset using link control block 0xC0.
Issue a request for Object 60 Variation 2.
Verify that the device responds with IIN1-7 set indicating the device has been restarted.
Issue a Write to Object 80 Variation 1 using the qualifier 0x00. Use a start index of 7 and a stop index of 7, followed by
the value 0 using the broadcast address (0xFFFF). Request a data link layer confirmation.
6. Wait a reasonable application layer timeout, for example, 2 seconds.
7. Verify that the device does not respond, with either a data link layer confirmation or a response to the Write operation.
8. Issue a request for Object 60 Variation 2.
9. Verify the DUT responds with a valid response with IIN1-7 (restart) cleared and IIN1-0 (all stations message received)
set.
10. Send an application layer confirmation if requested.
11. Issue a request for Object 60 Variation 2.
12. Verify the DUT responds with a Null Response with both IIN1-7 and IIN1-0 cleared.
8.6.5.3 Test Procedure
1.
2.
3.
4.
5.
6.
7.
8.
9.
Issue a Direct Operate No Acknowledgement using Object 12 Variation 1 to an installed point using 8-bit indexing
(qualifier 0x17), a control code supported by the device and an appropriate on/off-time using the broadcast address
(0xFFFF). If the device does not support control outputs, perform this operation using Object 41 Variation 2.
Verify the requested output operation was executed.
Wait a reasonable application layer timeout, for example, 2 seconds.
Verify that the device does not respond.
Issue a request for Object 60 Variation 2.
Verify the DUT responds with IIN1-0 (all stations message received) set.
Send an application layer confirmation if requested.
Issue a request for Object 60 Variation 2.
Verify the DUT responds with a Null Response with IIN1-0 cleared.
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8.6.5.4 § Test Procedure, Confirmed Response Options
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
14.
Cycle the power to the DUT.
Issue a link reset using link control block 0xC0.
Issue a request for Object 60 Variation 2.
Verify that the device responds with IIN1-7 set indicating the device has been restarted.
Issue a Write to Object 80 Variation 1 using the qualifier 0x00. Use a start index of 7 and a stop index of 7, followed by
the value 0. Specify broadcast address FFFE. Request a data link layer confirmation.
Wait a reasonable application layer timeout, for example, 2 seconds.
Verify that the device does not respond, with either a data link layer confirmation or a response to the Write operation.
Issue a request for Object 60 Variation 2.
Verify the DUT responds with a Null Response with IIN1-7 (restart) cleared and IIN1-0 (all stations message received)
set, and an application layer confirmation requested.
Before sending the requested confirmation, repeat the request for Object 60 Variation 2, and verify that IIN1-0 is still set
in the response.
Send the application layer confirmation.
Issue a request for Object 60 Variation 2.
Verify the DUT responds with a Null Response with both IIN1-7 and IIN1-1 cleared.
Repeat steps 1-13 using address FFFD as the broadcast address. In step 9, verify that an application layer confirmation is
NOT requested. In step 10, verify that IIN1-0 is not set in the response. Note: Step 11 will not be necessary.
8.6.6 Buffer Overflow
The Buffer Overflow Bit of the Internal Indications field is set to 1 when any event buffers overflow such that change event
data is subsequently being lost. This bit is cleared when the master station confirms change event data from the DUT, hence
making event buffer space available.
8.6.6.1 Desired Behavior
•
•
The DUT must set IIN2-3 after a given event buffer overflows such that change events are being lost.
The DUT must clear IIN2-3 after a master confirms a change event(s) from the DUT such that event buffer space is
made available.
8.6.6.2 Test Procedure
8.6.6.2.1 Buffer Overflow, Binary Input Change Event Buffers
1.
If the device does not support Binary Input Change Events, end testing of Buffer Overflow, Binary Input Change Event
Buffers.
2. Issue a request for Object 60 Variations 2,3 and 4 using the all data qualifier 0x06 to empty the device of pending events.
3. Obtain the maximum Binary Input Change Event buffer size from the device documentation and generate this number of
corresponding events on the DUT.
4. Issue a request for Object 60 Variation x (appropriate Class) using the all data qualifier 0x06, but DO NOT issue an
application confirm to the device.
5. Verify that IIN2-3 is NOT set.
6. Generate 1 additional change event of this type on the DUT.
7. Issue a request for Object 60 Variation x using the limit data qualifier 0x07 requesting a single change.
8. Verify that the device returns a single Binary Input Change Event and IIN2-3 is set.
9. Issue a request for Object 60 Variation x using the limit data qualifier 0x07 requesting a single change.
10. Verify that the device returns a single Binary Input Change Event and IIN2-3 is not set.
8.6.6.2.2 Buffer Overflow, Analog Input Change Event Buffers
1.
2.
If the device does not support Analog Input Change Events, or does not queue multiple events for the same point, end
testing of Buffer Overflow, Analog Input Change Event Buffers.
Issue a request for Object 60 Variations 2,3 and 4 using the all data qualifier 0x06 to empty the device of pending events.
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3.
Obtain the maximum Analog Input Change Event buffer size from the device documentation and generate this number of
corresponding events on the DUT.
4. Issue a request for Object 60 Variation x (appropriate Class) using the all data qualifier 0x06, but DO NOT issue an
application confirm to the device.
5. Verify that IIN2-3 is NOT set.
6. Generate 1 additional change event of this type on the DUT.
7. Issue a request for Object 60 Variation x using the limit data qualifier 0x07 requesting a single change.
8. Verify that the device returns a single Analog Input Change Event and IIN2-3 is set.
9. Issue a request for Object 60 Variation x using the limit data qualifier 0x07 requesting a single change.
10. Verify that the device returns a single Analog Input Change Event and IIN2-3 is not set.
8.6.6.2.3 Buffer Overflow, Binary Counter Change Event Buffers
1.
If the device does not support Binary Counter Change Events, or does not queue multiple events for the same point, end
testing of Buffer Overflow, Binary Counter Change Event Buffers.
2. Issue a request for Object 60 Variations 2,3 and 4 using the all data qualifier 0x06 to empty the device of pending events.
3. Obtain the maximum Binary Counter Change Event buffer size from the device documentation and generate this number
of corresponding events.
4. Issue a request for Object 60 Variation x (appropriate Class) using the all data qualifier 0x06, but DO NOT issue an
application confirm to the device.
5. Verify that IIN2-3 is NOT set.
6. Generate 1 additional change event of this type.
7. Issue a request for Object 60 Variation x using the limit data qualifier 0x07 requesting a single change.
8. Verify that the device returns a single Binary Counter Change Event and has set IIN2-3.
9. Issue a request for Object 60 Variation x using the limit data qualifier 0x07 requesting a single change.
10. Verify that the device returns a single Binary Counter Change Event and IIN2-3 is no longer set.
8.7 Time
§ If the device sets IIN1-4, the Device Profile must state the worst case values for the following parameters for the full
operating temperature and support all of the tests in this section.
• Time base drift over a 10-minute interval.
• Maximum delay measurement error.
• Maximum internal time reference error when set from the protocol.
• Maximum response time.
If a device does not set IIN1-4 it need not support any of the tests in this section.
8.7.1 Delay Measurement
This function is used to calculate the communication delay for a particular device. The device will respond to a Time Delay
Measurement request with the number of milliseconds elapsed between the device receiving the first bit of the first byte of
the request and the time of transmission of the first bit of the first byte of the response.
8.7.1.1 Desired Behavior
•
§ The device must respond to a Delay Measurement request with a Time Delay Fine response.
8.7.1.2 Test Procedure
1.
2.
3.
4.
Issue a request for Delay Measurement using Function Code 23, to the DUT.
Verify that the device replies with Object 52 Variation 2 Qualifier 0x07 Quantity 1 and a millisecond time stamp of the
measured delay.
Verify that the accuracy of the delay reported is within the maximum error specified in the Device Profile Document.
Perform the test two more times to guarantee repeatability.
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8.7.2 Synchronization
The Time and Date Object (Object 50 Variation 01) is an information object that represents the absolute time of day and date,
recorded as milliseconds since midnight, January 1, 1970, at zero minutes, zero seconds, and zero milliseconds. This object is
usually used for time-synchronization.
Note that the following procedures verify the mechanics of time synchronization, verify that the time format is correct, and
that synchronization appears to have occurred. The actual accuracy of time synchronization is dependent on device accuracy
and system configuration and should be tested separately (factory and/or site acceptance tests).
8.7.2.1 Desired Behavior
•
•
The device must respond to a Time and Date object by null response with IIN1-4 cleared.
§ The Device Profile must specify the maximum time from startup to IIN1-4 assertion.
8.7.2.2 Test Procedure
1.
2.
3.
4.
5.
6.
7.
8.
9.
Reset the DUT.
Wait the specified maximum time from reset to IIN1-4 assertion.
Issue a request for Object 60 Variation 2 using the all data qualifier 0x06.
Verify that the device responds with a valid message and that IIN1-4 is set indicating that the device is requesting time
synchronization.
Set the time and date using a WRITE request and Object 50 Variation 1 with Qualifier 0x07 taking into account the
delay measured in the previous section.
Verify that the device responds with a Null Response and that IIN1-4 is cleared indicating the device no longer needs
time.
Generate a supported time tagged event at a known time.
Issue a request for Object 60 Variation 2, 3, or 4 as appropriate, using the all data qualifier 0x06.
Verify that the device responds with a valid time tagged event and that the time reported is within the maximum error
specified in the Device Profile Document.
8.8 Cold Restart
8.8.1 Desired Behavior
•
The device must respond to a Cold Restart request by sending a Time Delay response, restarting, and setting IIN1-7.
8.8.2 Test Procedure
1.
2.
3.
4.
5.
6.
7.
8.
Issue a request for Cold Restart using Function Code 13, to the DUT.
Verify the response is a Time Delay Fine or Coarse (Object 52 Variation 1 or Variation 2).
If the DUT requests an Application Layer Confirm send it before starting the wait period.
Wait for a period of time longer than the time returned in step 2.
Issue a request for Object 60 Variation 1.
Verify that the device responds with IIN1-7 set indicating that the device has been restarted.
Issue a Write using Object 80 Variation 1 with the qualifier 0x00. Use a start index of 7 and a stop index of 7, followed
by the value 0.
Verify that the device responds with a Null Response and that IIN1-7 is cleared.
8.9 Application Layer Fragmentation
8.9.1 Use of FIR, FIN and SEQUENCE in Fragmentation
8.9.1.1 Desired Behavior
If the DUT can generate enough data to create multiple application layer fragments, it must meet the following criteria:
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•
•
•
•
•
•
•
•
The application layer FIR bit must be set in the first fragment (only).
The application layer FIN bit must be set in the final fragment (only).
The application layer sequence number of the first fragment must match that of the request.
The application layer sequence number must increment between fragments.
Transport layer segmentation must operate correctly within each fragment.
The fragment size must be able to be configured to be no larger than 2048 octets.
If the fragment size is configurable, it must behave accordingly.
If the device cannot generate more than one fragment, the FIR and FIN bits in the application layer header must signify
that there is only one APDU in the reply.
8.9.1.2 Test Procedure
1.
2.
3.
If the DUT has a configurable fragment size, configure it to be no more than 2048 octets.
Cycle power to the DUT.
Request Class 0 data (Object 60 Variation 1) using Qualifier Code 0x06, if this will generate a multi-fragment response.
Alternately, generate enough event data to fill more than one fragment and request the appropriate class of data with
Qualifier Code 0x06.
4. Verify that the DUT responds with valid data.
5. Verify that the sequence number of the first fragment matches the request.
6. Verify that each fragment of the response contains no more than the configured fragment size.
7. If the DUT’s reply contains only a single fragment then verify the FIR bit is set to one and the FIN bit is also set to one.
If there is no way to cause the DUT to generate multiple fragments, i.e. its Class 0 response is less than a fragment and it
does not support event data, no further testing is required in the Application Layer Fragmentation section.
8. If the DUT’s reply contains more than one fragment then verify that the first response message sets the FIR bit to a one,
the FIN bit is set to zero.
9. Verify subsequent fragments to assure that the FIR bit is zero, the FIN bit is zero, and the sequence number increments
by one.
10. Verify that the last fragment has the FIR bit cleared and the FIN bit set, signifying the last data fragment.
11. Verify each fragment is properly segmented by the transport layer as described in that section of this document.
12. If the DUT’s fragment size is configurable, repeat this test with a different fragment size and verify the data for each
fragment does not exceed the configured size.
8.9.2 § Use of Confirmation in Fragmentation
8.9.2.1 § Desired Behavior
•
•
•
The DUT must request an application layer confirmation between fragments.
The DUT must not send subsequent fragments until it receives confirmation of the previous fragment, with a correct
sequence number.
The DUT must not send subsequent fragments if it does not receive a valid confirmation within a timeout.
NOTE: The DUT is not required to request application layer confirmation on the last fragment of a response (unless required
for other reasons tested elsewhere in this document).
8.9.2.2 § Test Procedure
1.
2.
3.
4.
5.
6.
Request Class 0 data (Object 60 Variation 1) using Qualifier Code 0x06, if this will generate a multi-fragment response.
Alternately, generate enough event data to fill more than one fragment and request the appropriate class of data with
Qualifier Code 0x06.
Verify that the DUT responds with valid data.
Verify that the CON bit is set in the first fragment.
Verify the sequence number matches the request.
Wait the application confirmation timeout for the DUT. Do not send an application confirmation.
Verify the DUT does not send the next fragment because it did not receive confirmation of the first fragment.
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7.
8.
9.
10.
11.
12.
13.
14.
15.
16.
17.
18.
19.
20.
Send the valid application layer confirmation.
Verify the DUT does not send the next fragment because it has timed out.
Request Class 0 data (Object 60 Variation 1) using Qualifier Code 0x06, if this will generate a multi-fragment response.
Alternately, generate enough event data to fill more than one fragment and request the appropriate class of data with
Qualifier Code 0x06.
Verify that the CON bit is set in the first fragment.
Wait a time period less than the application confirmation timeout. Verify the DUT does not send the second fragment
yet.
Send the valid application layer confirmation before the application confirmation timeout.
Verify that the DUT sends the second fragment (with FIR, FIN and sequence number set correctly).
Verify that the CON bit is set in the second fragment.
If a third fragment is expected, continue. If not, first send a valid application layer confirmation and then a request for
multi-fragment data as in steps 1-3.
Send an application layer confirmation with an incorrect sequence number.
Wait the application layer confirmation timeout for the DUT. Do not send an application confirmation.
Verify the DUT does not send the next fragment because the confirmation it received was invalid.
Send the valid application layer confirmation.
Verify the DUT does not send the next fragment because it has timed out.
8.10 Multi-Drop Support
8.10.1 Desired Behavior
•
•
The DUT must only respond to requests when the destination address field of the link layer portion of the request
matches its assigned DNP address.
The DUT must remain silent in all other cases. This includes not raising carrier (e.g. asserting RTS) during periods in
which it is not responding.
8.10.2 Test Procedure
1.
2.
3.
4.
5.
6.
7.
8.
9.
If the DUT does not support multi-drop physical layers, this must be noted on the Implementation Conformance
Statement and in the Device Profile Document. No further testing is required in this section.
Connect the DUT and at least two additional DNP devices to the same communications drop.
Connect an oscilloscope and/or protocol analyzer to the DUT communications signals.
Issue a request for Object 60 Variations 2,3, and 4 using the all data qualifier 0x06 to each of the other devices on the
communications channel.
Verify that the DUT does not respond in any way, including raising carrier or asserting RTS.
Issue a request for Object 60 Variations 2,3, and 4 using the all data qualifier 0x06 to the broadcast address.
Verify that the DUT does not respond in any way, including raising carrier or asserting RTS.
Issue a request for Object 60 Variations 2,3, and 4 using the all data qualifier 0x06 to the DUT.
Repeat as necessary to verify that the DUT responds in an appropriate manner for the physical layer which may include:
a) Raising carrier (or asserting RTS) an appropriate period of time before transmitting the first bit of data.
b) Dropping carrier (or de-asserting RTS) an appropriate period of time after transmitting the last bit of data.
c) If the pre and post RTS to transmit delay parameters are configurable, repeat this test for the lower of the two
following cases.
i) the total number of selections or
ii) the minimum, maximum, and two intermediate values
8.11 Unsolicited Responses
Support for unsolicited responses is optional. If a device does not support unsolicited responses, this section may be skipped
in its entirety.
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Although unsolicited responses may be used with collision avoidance, the two features are independent. For instance, a
device might not support collision avoidance, but support unsolicited responses in a dial-up environment. Therefore, all that
is needed to test unsolicited responses is a full-duplex serial connection to the DUT.
8.11.1 Desired Behavior
8.11.1.1
Configuration
Devices that support unsolicited responses must support end-user configuration of the following parameters (e.g.: by
front-panel user interface or off-line configuration):
• The destination address of the Master device to which the unsolicited responses are to be sent.
• The unsolicited response mode (either “on” or “off”). When the unsolicited response mode is configured “off”, the
device is to behave exactly like an equivalent device that has no support for unsolicited responses.
• § The unsolicited confirmation timeout. This is the amount of time between transmissions of unconfirmed unsolicited
responses. The range of configurable values must include 1 second to 1 minute, but may be extended in either direction
(slower or faster) to take advantage of, or to compensate for, faster or slower devices or communications media. This
may be either the normal application confirmation timeout, or another parameter that performs the same purpose only for
unsolicited responses.
• § Maximum number of unsolicited retry attempts. One of the choices must provide for an indefinite (and potentially
infinite) number of retries.
8.11.1.2
Sequence Numbers and Confirmation
At all times:
• Application layer sequence numbers (the value of bits 0–4 of the application layer control field) must be in the correct
range for all messages sent: 0–15 for polled responses and 16–31 for unsolicited responses.
• Ignore Master device application layer confirmations of unsolicited responses if their sequence numbers do not match
those of the corresponding unsolicited responses.
• § All unsolicited response messages must request application layer confirmation, regardless of whether they are null (no
data) or contain data.
8.11.1.3
Restart Behavior
If the unsolicited response mode is configured “on,” then upon device restart:
• The device must transmit an initial unsolicited response message.
• The initial unsolicited response message must have the restart bit (IIN1-7) set if the Master has not already sent a
command to clear it.
• § The initial unsolicited response message must be null; i.e., it must not contain static or event data objects.
• § The initial unsolicited response message must request an application layer confirmation, regardless of whether the
message has the restart bit (IIN1-7) set.
• § The device must continue to transmit initial null unsolicited responses at the rate set by the unsolicited confirmation
timeout, until that initial unsolicited response message is confirmed.
• § The device must respond to all function requests to which it would normally respond, including READ function
requests, while waiting for the confirmation of the initial unsolicited response.
• § The device must not send any more unsolicited responses after the initial null unsolicited response message has been
confirmed, until a function code 0x14 (enable data-filled unsolicited messages) request has been received.
8.11.1.4
Runtime Behavior
Once an initial unsolicited response message has been confirmed, then the device must:
• § Process function code 0x14 requests (to enable data-filled unsolicited messages). This enabled status must not be
retained through a device restart; i.e. data-filled unsolicited messages are always disabled on restart.
• § Process function code 0x15 requests (to disable data-filled unsolicited messages). This disabled status does not apply to
initial null unsolicited responses; i.e., if function code 0x15 is requested, and if no off-line configuration is altered, then
after restart, an initial unsolicited response message must again be transmitted.
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•
•
•
§ At a minimum, support the enabling and disabling of unsolicited responses for Class 1, 2, and 3 data. Even if the
device does not have Class 1, Class 2, or Class 3 data, it must respond to function codes 0x14 and 0x15, object 60, and
variations 2, 3 and 4 without error responses.
Only send unsolicited responses for those classes of data that have been enabled.
Unsolicited response messages must contain only the following kinds of data:
! event data, or
! static data for which no event object types exist: binary output status (Object 10 Variation 2) and analog output
status (Object 40 Variation 2). Note, when static data is returned in unsolicited responses, the rules for event
processing still apply as specified in section 3.4.
8.11.1.5
•
•
•
•
•
•
•
Unsolicited and Polled Responses
If an unsolicited response message containing event data is not confirmed, the device must timeout, retain the event data,
and re-transmit the event data either in subsequent unsolicited response messages or in polled response messages. The
event data does not have to be re-transmitted exactly (new change events may have occurred, or, for example, analog
input change events may be updated to reflect new current values of analog inputs).
Once an unsolicited response message containing event data is confirmed, the event data must be cleared from the device
and no longer transmitted in subsequent unsolicited or polled responses.
The device cannot generate unsolicited responses if it is waiting for an application confirmation to a previous polled or
unsolicited response.
If a non-READ function code request is received while waiting for a confirmation of an unsolicited response, the device
must immediately process it.
§ If a READ function code request is received while waiting for a confirmation of an unsolicited response, the device
must defer responding to the READ request (the READ request is therefore “pending”) until after either the unsolicited
confirmation timeout occurs, or the confirmation of the unsolicited response is received.
§ The device cannot generate an additional unsolicited response until it has responded to a pending READ request.
§ If a READ function code request is pending while waiting for a confirmation of an unsolicited response, and another
(new) function code request is received, the original READ function code request must be abandoned (with no response
transmitted), and the new function code should be processed according the desired behavior rules of this section.
8.11.2 Test Procedure
Unless explicitly specified by the tests in these sections, do not issue any requests to the DUT, including: requests to clear the
restart bit (IIN1-7); READ requests for data; application layer confirmations and requests to enable or disable unsolicited
responses. Similarly, do not allow the Master being used to test the device to issue any of these requests automatically.
8.11.2.1
Unsolicited Response Configuration/Startup
1.
Verify that the DUT has off-line capability to configure the unsolicited response mode (either “on” or “off”). Use this
capability to configure the unsolicited response mode to “on.”
2. § Verify the DUT has off-line capability to configure the unsolicited confirmation timeout. Verify that it can be set to at
least as small as 1 second, and to at least as large as 1 minute.
3. For the remainder of Section 8.11.2.1, set this time to be 5 seconds. (The value of 5 seconds is arbitrary, and is used to
simplify the description and execution of this test. As a further simplification for the purposes of this test, when the test
steps below exercise and rely upon this value, measurement accuracy can be within 0.5 seconds. It is not the purpose of
this test to verify the full range of this parameter, nor is it the purpose of this test to verify the accuracy of the time
keeping capability of the DUT. It is the purpose of this test, however, to verify that the parameter has been
implemented.)
4. Verify the DUT has off-line capability to configure the destination address of the Master device to which unsolicited
responses are to be sent. Use this capability to configure a specific destination address.
5. Cycle power to the DUT.
6. Verify that the DUT transmits an initial unsolicited response to the configured Master destination address.
7. Use the off-line configuration capability to configure the destination address to a different destination address.
8. Cycle power to the DUT.
9. Verify that an initial unsolicited response is transmitted by the DUT.
10. Verify that the unsolicited response contains the restart bit (IIN1-7) set.
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11.
12.
13.
14.
15.
16.
17.
18.
19.
20.
21.
22.
23.
24.
25.
26.
27.
28.
29.
30.
§ Verify that the unsolicited response is null (contains no data).
§ Verify that the unsolicited response requests an application layer confirmation.
Verify that the application sequence number is in the correct range.
Verify that it has been transmitted to the configured Master destination address.
Wait at least 10 seconds, and verify that two or more unsolicited responses are transmitted by the DUT. Verify that these
new unsolicited responses are transmitted no more often, and no less often, than once every 5 seconds.
Verify that the restart bit (IIN1-7) remains set in these unsolicited responses.
§ Verify that the unsolicited responses are null (contains no data).
§ Verify that the unsolicited responses request application layer confirmations.
Issue a request to clear the restart bit (IIN1-7).
Verify that the DUT responds with a null response that has the restart bit (IIN1-7) cleared.
Wait at least 5 seconds, and verify that another unsolicited response is transmitted by the DUT.
Verify that the restart bit (IIN1-7) is clear in the unsolicited responses.
Issue a READ request (function code 0x01) for Object 60 Variation 1 (class 0) using the all data qualifier 0x06.
§ Verify that the DUT responds to the READ request with class 0 data.
Wait at least 5 seconds, and verify that another unsolicited response is transmitted by the DUT.
Issue an application layer confirmation of the unsolicited response, but use an incorrect application-layer sequence
number.
Wait at least 5 seconds, and verify that another unsolicited response is transmitted by the DUT.
Issue an application-layer confirmation of the unsolicited response, and use the correct application-layer sequence
number.
Generate known events.
§ Verify that no further unsolicited responses are transmitted by waiting for such responses for at least 5 seconds.
8.11.2.2
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
14.
15.
16.
Unsolicited Response - Class 1 Data
Issue a request to disable unsolicited responses for all classes of data by using function code 0x15 with three object data
headers: Object 60, Variation 2; Object 60, Variation 3; and Object 60, Variation 4.
Verify that the DUT responds with a null response indicating the request was processed without error.
If the DUT has Class 1 data, generate such data. For example, if there is a binary input change event that is (or can be
assigned to) Class 1, then ensure that it is assigned to Class 1, and generate one such event.
Verify that no unsolicited responses are transmitted by waiting for such responses for a length of time at least as great as
what would be necessary for the DUT to otherwise generate an unsolicited response.
Issue a request to enable unsolicited responses for Class 1 data by using function code 0x14, object 60, Variation 2.
Verify that the DUT responds with a null response indicating the request was processed without error.
If it is not possible to generate Class 1 data that would generate unsolicited responses, steps 8 through 14 are not
applicable.
Verify that an unsolicited response is transmitted. This may involve waiting for an amount of time, dictated by the DUT
and specified by the DUT’s Device Profile Document, within which the DUT may wait for a minimum number of events
to be collected before transmission of an unsolicited message.
Verify that the unsolicited response requests an application layer confirmation.
Verify that the application sequence number is in the correct range.
Without issuing an application layer confirmation, wait for the unsolicited confirmation timeout to expire, and verify that
another unsolicited response is transmitted by the DUT.
Verify that at least the same event data is present in the unsolicited response. (It is not required that the unsolicited
responses be identical. For data such as analog input change events, the data may be updated to reflect current values. It
is also possible for new event data to have been generated.)
Issue an application layer confirmation of the unsolicited response, but use an incorrect application-layer sequence
number.
Wait for the unsolicited confirmation timeout to expire, and verify that another unsolicited response is transmitted by the
DUT, still containing the same event data.
Issue an application-layer confirmation of the unsolicited response, and use the correct application-layer sequence
number.
If the DUT has Class 2 data, then generate such data. If the DUT has Class 3 data, then also generate Class 3 data.
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17. Verify that no further unsolicited responses are transmitted by waiting for such responses for a length of time at least as
great as what would be necessary for the DUT to otherwise generate an unsolicited response.
8.11.2.3
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
14.
15.
16.
17.
Unsolicited Response - Class 2 Data
Issue a request to disable unsolicited responses for all classes of data by using function code 0x15 with three object data
headers: Object 60, Variation 2; Object 60, Variation 3; and Object 60, Variation 4.
Verify that the DUT responds with a null response indicating the request was processed without error.
If the DUT has Class 2 data, generate such data. For example, if there is a binary input change event that is (or can be
assigned to) Class 2, then ensure that it is assigned to Class 2, and generate one such event.
Verify that no unsolicited responses are transmitted by waiting for such responses for a length of time at least as great as
what would be necessary for the DUT to otherwise generate an unsolicited response.
Issue a request to enable unsolicited responses for Class 2 data by using function code 0x14, Object 60, Variation 3.
Verify that the DUT responds with a null response indicating the request was processed without error.
If it is not possible to generate Class 2 data that would generate unsolicited responses, steps 8 through 14 are not
applicable.
Verify that an unsolicited response is transmitted. This may involve waiting for an amount of time, dictated by the DUT
and specified by the DUT’s Device Profile Document, within which the DUT may wait for a minimum number of events
to be collected before transmission of an unsolicited message.
Verify that the unsolicited response requests an application layer confirmation.
Verify that the application sequence number is in the correct range.
Without issuing an application layer confirmation, wait for the unsolicited confirmation timeout to expire, and verify that
another unsolicited response is transmitted by the DUT.
Verify that at least the same event data is present in the unsolicited response. (It is not required that the unsolicited
responses be identical. For data such as analog input change events, the data may be updated to reflect current values. It
is also possible for new event data to have been generated.)
Issue an application layer confirmation of the unsolicited response, but use an incorrect application-layer sequence
number.
Wait for the unsolicited confirmation timeout to expire, and verify that another unsolicited response is transmitted by the
DUT, still containing the same event data.
Issue an application-layer confirmation of the unsolicited response, and use the correct application-layer sequence
number.
If the DUT has Class 1 data, then generate such data. If the DUT has Class 3 data, then also generate Class 3 data.
Verify that no further unsolicited responses are transmitted by waiting for such responses for a length of time at least as
great as what would be necessary for the DUT to otherwise generate an unsolicited response.
8.11.2.4
Unsolicited Response - Class 3 Data
1.
Issue a request to disable unsolicited responses for all classes of data by using function code 0x15 with three object data
headers: Object 60, Variation 2; Object 60, Variation 3; and Object 60, Variation 4.
2. Verify that the DUT responds with a null response indicating the request was processed without error.
3. If the DUT has Class 3 data, generate such data. For example, if there is a binary input change event that is (or can be
assigned to) Class 3, then ensure that it is assigned to Class 3, and generate one such event.
4. Verify that no unsolicited responses are transmitted by waiting for such responses for a length of time at least as great as
what would be necessary for the DUT to otherwise generate an unsolicited response.
5. Issue a request to enable unsolicited responses for Class 3 data by using function code 0x14, Object 60, Variation 4.
6. Verify that the DUT responds with a null response indicating the request was processed without error.
7. If it is not possible to generate Class 2 data that would generate unsolicited responses, steps 8 through 14 are not
applicable.
8. Verify that an unsolicited response is transmitted. This may involve waiting for an amount of time, dictated by the DUT
and specified by the DUT’s Device Profile Document, within which the DUT may wait for a minimum number of events
to be collected before transmission of an unsolicited message.
9. Verify that the unsolicited response requests an application layer confirmation.
10. Verify that the application sequence number is in the correct range.
11. Without issuing an application layer confirmation, wait for the unsolicited confirmation timeout to expire, and verify that
another unsolicited response is transmitted by the DUT.
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12. Verify that at least the same event data is present in the unsolicited response. (It is not required that the unsolicited
responses be identical. For data such as analog input change events, the data may be updated to reflect current values. It
is also possible for new event data to have been generated.)
13. Issue an application layer confirmation of the unsolicited response, but use an incorrect application-layer sequence
number.
14. Wait for the unsolicited confirmation timeout to expire, and verify that another unsolicited response is transmitted by the
DUT, still containing the same event data.
15. Issue an application-layer confirmation of the unsolicited response, and use the correct application-layer sequence
number.
16. If the DUT has Class 1 data, then generate such data. If the DUT has Class 2 data, then also generate Class 2 data.
17. Verify that no further unsolicited responses are transmitted by waiting for such responses for a length of time at least as
great as what would be necessary for the DUT to otherwise generate an unsolicited response.
8.11.2.5
Unsolicited and Polled Responses
This is a complicated test procedure. The test has been divided into sections for clarity.
8.11.2.5.1 Transmits data-filled unsolicited responses
1.
2.
3.
4.
5.
Issue a request to enable unsolicited responses for all classes of data by using function code 0x14 with three object data
headers: Object 60, Variation 2; Object 60, Variation 3; and Object 60, Variation 4.
Verify that the DUT responds with a null response indicating the request was processed without error.
Generate class 1, 2, or 3 event data.
Verify that an unsolicited response is transmitted. This may involve waiting for an amount of time, dictated by the DUT
and specified by the DUT’s Device Profile Document, within which the DUT may wait for a minimum number of events
to be collected before transmission of an unsolicited message.
Verify that the unsolicited response requests an application layer confirmation.
8.11.2.5.2 Clears transmitted data upon confirmation
1.
2.
3.
Issue an application-layer confirmation of the unsolicited or polled response.
Issue a READ request (function code 0x01) for Object 60 Variations 2, 3, and 4 using the all data qualifier 0x06.
Verify that none of the event data transmitted by the unsolicited response is contained in the polled response.
8.11.2.5.3 Processes non-READ requests immediately
1.
2.
3.
4.
5.
Generate class 1, 2, or 3 event data to trigger the transmission of an unsolicited response. Wait for this unsolicited
response to be sent.
Without issuing an application layer confirmation, issue a function code request other than READ (for example, function
code 0x02 – WRITE to clear the restart flag IIN1-7).
Verify that the DUT immediately responds without error.
Wait for the unsolicited confirmation timeout to expire, and verify that another unsolicited response is transmitted by the
DUT.
Verify that the event data in this unsolicited response includes the events reported in the previous unsolicited response
that was not confirmed. It is not required that the unsolicited responses be identical. For data such as analog input change
events, the data may be updated to reflect current values. It is also possible for new event data to be generated.
8.11.2.5.4 Defers READ requests until after confirmation received
1.
2.
3.
4.
5.
6.
Immediately after the unsolicited response, and without issuing an application layer confirmation, issue a READ request
(function code 0x01) for Object 60 Variations 2, 3, and 4 using the all data qualifier 0x06.
Wait for an amount of time less than the unsolicited confirmation timeout and verify that the DUT does not respond.
Issue an application-layer confirmation of the unsolicited response before the unsolicited confirmation timeout occurs.
Verify that the device immediately transmits a response to the READ request.
Verify that none of the event data transmitted by the unsolicited response is contained in the polled response.
If the polled response requested an application layer confirmation, then issue an application-layer confirmation of the
polled response.
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8.11.2.5.5 Defers READ requests until after confirmation timeout
1.
2.
3.
4.
5.
6.
7.
8.
Generate class 1, 2, or 3 event data to trigger the transmission of an unsolicited response. Wait for this unsolicited
response to be sent.
Immediately after the unsolicited response, and without issuing an application layer confirmation, issue a READ request
(function code 0x01) for Object 60 Variations 2, 3, and 4 using the all data qualifier 0x06.
Verify that the DUT does not respond within the unsolicited confirmation timeout.
After the unsolicited confirmation timeout, verify that the device responds with a polled response to the READ request
(and not an unsolicited response).
Verify that the polled response contains at least the same event data that was in the unsolicited response that was not
confirmed.
Verify that the polled response requests an application layer confirmation.
Issue an application-layer confirmation of the polled response to clear the device of event data.
Verify that no further unsolicited responses are transmitted by waiting for such responses for a length of time at least as
great as what would be necessary for the DUT to otherwise generate an unsolicited response.
8.11.2.5.6 Abandons READ requests upon subsequent non-READ requests
1.
2.
3.
4.
5.
6.
Generate class 1, 2, or 3 event data to trigger the transmission of an unsolicited response. Wait for this unsolicited
response to be sent.
Immediately after the unsolicited response, and without issuing an application layer confirmation, issue a READ request
(function code 0x01) for Object 60 Variations 2, 3, and 4 using the all data qualifier 0x06.
Before the unsolicited confirmation timeout, issue a function code request other than READ (for example, function code
0x02 – WRITE to clear the restart flag IIN1-7).
Verify that the DUT immediately responds without error.
Wait for the unsolicited confirmation timeout to expire, and then verify that another unsolicited response is transmitted
by the DUT.
Verify that the event data in this unsolicited response includes the events reported in the previous unsolicited response
that was not confirmed.
8.11.2.5.7 Abandons READ requests upon subsequent READ requests
1.
2.
3.
4.
5.
6.
7.
8.
9.
Immediately after the unsolicited response, and without issuing an application layer confirmation, issue a READ request
(function code 0x01) for Object 60 Variation 1 using the all data qualifier 0x06.
Before the unsolicited confirmation timeout, issue a READ request for Object 60, Variations 2, 3, and 4, using the all
data qualifier 0x06.
Verify that the DUT does not respond within the unsolicited confirmation timeout.
After the unsolicited confirmation timeout, verify that the device responds with a polled response to the Object 60,
Variation 2, 3, and 4 READ request (and not an unsolicited response).
Verify that the polled response is a response to the request for Object 60, Variations 2, 3, and 4 – not Variation 1; in
other words, verify that it contains class 1, 2, or 3 data and not class 0 data.
Verify that the polled response contains at least the same event data that was in the unsolicited response that was not
confirmed.
Verify that the polled response requests an application layer confirmation.
Issue an application-layer confirmation of the polled response to clear the device of event data.
Verify that no further unsolicited responses are transmitted by waiting for such responses for a length of time at least as
great as what would be necessary for the DUT to otherwise generate an unsolicited response.
8.11.2.5.8 Inhibits Unsolicited responses until after polled confirmation
1.
2.
If the device has a minimum amount of event data that will cause the immediate transmission of an unsolicited response,
then generate at least some, but less than this amount of class 1, 2, or 3 event data. Or, if there is a window of time
between the generation of event data and the subsequent transmission of an unsolicited response, then generate event
data and perform the next test procedure step before this time elapses. If neither of these procedures are possible, then the
remaining steps in this procedure are not applicable.
Before an unsolicited response is transmitted, issue a READ request (function code 0x01) for Object 60 Variations 2, 3,
and 4 using the all data qualifier 0x06.
DNP3-2001 IED Certification Procedure
Subset Level 1
Page 51
Rev 2.1 – 5-July-01
3.
4.
5.
6.
7.
Verify that events are reported in the response to the READ request
Verify that the polled response requests an application layer confirmation.
Do not send an application layer confirmation.
If necessary, generate more event data that would otherwise cause the transmission of an unsolicited response.
Verify that the DUT does not transmit an unsolicited response within the application confirmation timeout, nor before
any application layer retries are attempted.
8. After the application confirmation timeout, and after any application layer retries, verify that the device responds with an
unsolicited response.
9. Verify that the unsolicited response contains at least the same event data that was in the polled response that was not
confirmed.
10. Verify that the unsolicited response requests an application layer confirmation.
11. Issue an application-layer confirmation of the unsolicited response to clear the device of event data.
8.11.2.5.9 Retries unsolicited responses configurable number of times
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
14.
15.
16.
17.
18.
19.
20.
21.
22.
23.
24.
25.
26.
27.
28.
Verify the DUT has off-line capability to configure the maximum number of unsolicited retries and that one of the
choices causes the DUT to retry indefinitely. Use this capability to configure the maximum number of retries to 5.
Cycle power to the DUT.
Issue an application-layer confirmation of the initial unsolicited response.
Issue a request to clear the restart bit (IIN1-7).
Issue a request to enable unsolicited responses for all classes of data by using function code 0x14 with three object data
headers: Object 60, Variation 2; Object 60, Variation 3; and Object 60, Variation 4.
Verify that the DUT responds with a null response indicating the request was processed without error.
Generate class 1, 2, or 3 event data.
Verify that an unsolicited response is transmitted. This may involve waiting for an amount of time, dictated by the DUT
and specified by the DUT’s Device Profile Document, within which the DUT may wait for a minimum number of events
to be collected before transmission of an unsolicited message.
Do not issue an application layer confirm.
Verify that DUT retries the response 5 times.
Cycle power to the DUT.
Issue an application-layer confirmation of the initial unsolicited response.
Issue a request to clear the restart bit (IIN1-7).
Issue a request to enable unsolicited responses for all classes of data by using function code 0x14 with three object data
headers: Object 60, Variation 2; Object 60, Variation 3; and Object 60, Variation 4.
Verify that the DUT responds with a null response indicating the request was processed without error.
Generate class 1, 2, or 3 event data.
Verify that an unsolicited response is transmitted.
Issue an application layer confirm after at least one retry. Verify that retries are terminated when confirmation is
received.
Configure the maximum number of retries to indefinite.
Cycle power to the DUT.
Issue an application-layer confirmation of the initial unsolicited response.
Issue a request to clear the restart bit (IIN1-7).
Issue a request to enable unsolicited responses for all classes of data by using function code 0x14 with three object data
headers: Object 60, Variation 2; Object 60, Variation 3; and Object 60, Variation 4.
Verify that the DUT responds with a null response indicating the request was processed without error.
Generate class 1, 2, or 3 event data.
Verify that an unsolicited response is transmitted.
Do not issue an application layer confirm.
Verify that retries continue for an extended period of time.
8.11.2.6
1.
2.
Unsolicited Responses Off
Configure the unsolicited response mode to “off”.
Cycle power to the DUT.
DNP3-2001 IED Certification Procedure
Subset Level 1
Page 52
Rev 2.1 – 5-July-01
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
14.
15.
Verify that no initial unsolicited responses are transmitted by waiting for such responses for a length of time at least as
great as what would be necessary for the DUT to otherwise generate an unsolicited response.
Issue a request to clear the restart bit (IIN1-7).
Verify that the DUT responds with a null response that has the restart bit (IIN1-7) cleared.
Verify that no initial unsolicited responses are transmitted by waiting for such responses for a length of time at least as
great as what would be necessary for the DUT to otherwise generate an unsolicited response.
Issue a request for Object 60 Variations 3, 2, 1, and 0 using the all data qualifier 0x06 to cause the DUT to report (and
clear) all pending events.
If requested, issue an application layer confirm.
Generate several change events or other data, which would otherwise cause an unsolicited response.
Verify that no unsolicited responses are transmitted by waiting for such responses for a length of time at least as great as
what would be necessary for the DUT to otherwise generate an unsolicited response.
Issue a request to enable unsolicited responses for all classes of data by using function code 0x14 with three object data
headers: Object 60, Variation 2; Object 60, Variation 3; and Object 60, Variation 4.
Verify that the DUT responds with an Error Response with IIN2-0 set indicating that the DUT has received a message
containing a bad function code.
Verify that no unsolicited responses are transmitted by waiting for such responses for a length of time at least as great as
what would be necessary for the DUT to otherwise generate an unsolicited response.
Issue a request to disable unsolicited responses for all classes of data by using function code 0x15 with three object data
headers: Object 60, Variation 2; Object 60, Variation 3; and Object 60, Variation 4.
Verify that the DUT responds with an Error Response with IIN2-0 set indicating that the DUT has received a message
containing a bad function code.
8.12 § Collision Avoidance
The functions tested in this section are optional. However, if a device claims in its Device Profile Document that it
implements collision avoidance, it must pass the tests in this section to be compliant.
A device may be certified as supporting collision avoidance in one of the following ways:
• Detecting out-of-band carrier (e.g. DCD)
1. with the aid of an external device
2. without the aid of an external device
• Detecting transmitted data (e.g. TX/RX line).
For these tests, the supplier of the DUT must specify which method the DUT uses to detect other devices are transmitting. If
necessary, the supplier must supply hardware (modems etc.) and test equipment suitable for testing this feature.
The test equipment must be capable of measuring time between two characters transmitted on the link.
Although unsolicited responses may be used with collision avoidance, the two features are independent. For instance, a
device might not support collision avoidance, but support unsolicited responses in a dial-up environment. However,
unsolicited responses in a multi-drop environment require collision avoidance. The operation of collision avoidance is as
follows:
The physical layer must provide an indication to the data link layer of when the link is in use, e.g. using the DCD (Data
Carrier Detect) signal or simply monitoring all data on the link.
If a device prepares to transmit and finds the link busy, it waits until it is no longer busy, then waits a backoff_time as
follows:
backoff_time = fixed_delay + random( max_random_delay )
After the backoff_time, the device tries again, either indefinitely, or up to a configurable maximum number of retries. If a
maximum is used, the protocol behaves as if a link failure occurred, i.e. data is returned to buffers at the application layer and
application layer retries take place if desired.
DNP3-2001 IED Certification Procedure
Subset Level 1
Page 53
Rev 2.1 – 5-July-01
The fixed_delay can be adjusted per device to provide priority of access. For instance, it could be zero (0) for masters and
non-zero for all the slave devices. The fixed_delay for the slaves must be greater than the max_random_delay for the master.
This provides a minimum "window" of access time for the master(s). To absolutely guarantee the master’s priority, the
master would not have a random delay.
8.12.1 Desired Behavior
When implementing collision avoidance, the DUT must meet the following requirements:
• The fixed_delay and the max_random_delay must be configurable.
• The DUT must transmit as quickly as possible if no other device is transmitting.
• The DUT must wait the backoff_time when it tries to transmit and another device is already transmitting.
• The backoff_time must start at the moment when the other device stops transmitting.
• The backoff_time must be greater than the fixed_delay.
• The backoff_time must not exceed the fixed_delay plus the max_random_delay.
• If another device is still transmitting when the backoff_delay expires, the DUT must wait until the line becomes free and
then restart the backoff timer.
8.12.2 Test Procedure
1.
2.
3.
Request Class 1 data (Object 60 Variation 2) using Qualifier Code 0x06 and link control block 0xF4.
Verify the device responds with data. Measure the turnaround delay between receipt of the request and the response.
Prepare a request for Class 1 data as above, followed immediately by “noise” data sufficient to exceed the measured
turnaround delay and the fixed_delay but less than the turnaround delay plus the maximum backoff_delay. The noise
data may consist of a poll to a nonexistent device.
4. Send the request.
5. Verify the DUT sends a response AFTER the noise data has finished transmitting. Verify the noise and the response do
not overlap.
6. Verify the delay between the end of the noise data and the start of the response is less than the maximum back_off delay
and more than the fixed_delay plus the max_random_delay.
7. Repeat steps 4 through 6 at least 10 times. Verify the measured backoff_delay is different in each case although it
remains less than the maximum backoff_delay and the length of the noise data remains constant.
8. Add more noise data to the prepared request so that the noise data now exceeds several times the fixed_delay plus the
max_random_delay, then a gap in the noise less than the fixed_delay, followed by noise several times longer than
fixed_delay plus the max_random_delay.
9. Repeat steps 4 through 6 to verify the DUT will back off more than once.
10. Reconfigure the device with a different fixed_delay and maximum_random_delay.
11. Repeat steps 1 through 10.
DNP3-2001 IED Certification Procedure
Subset Level 1
Page 54
Rev 2.1 – 5-July-01
9 Appendix A – DNP3 Reference Sheets
QUICK REFERENCE FOR DNP DATA LINK CONTROL FIELD
Definitions:
MSB
LSB
1
DIR
FCB
Primary
FCV
PRM
FUNCTION CODE
0
7
6
DIR
PRM
FCB
FCV
DFC
0
DFC
5
4
Secondary
3
2
1
0
1 = Master, 0 = Remote
1 = Data Link Request, 0 = Data Link Response
Frame Count Bit, alternates 1 and 0
Frame Count Valid; 1 = valid, 0 = invalid
Data Flow Control; 1 = no buffers left
Function Codes:
Primary Frames (PRM=1)
Fn Code
Function
Frame Type
FCV
0
RESET link
SEND/CONFIRM
0
1
Reset User Process
SEND/CONFIRM
0
2
TEST link
SEND/CONFIRM
1
3
User Data
SEND/CONFIRM
1
4
User Data
SEND/NO REPLY
0
9
Request Link Status
REQUEST/RESPOND
0
Secondary Frames (PRM = 0)
Fn Code
Function
Frame Type
0
ACK
CONFIRM
1
NACK
CONFIRM
11
Link Status
RESPOND
DNP3-2001 IED Certification Procedure
Subset Level 1
Page 55
Rev 2.1 – 5-July-01
QUICK REFERENCE FOR DNP DATA LINK CONTROL FIELD
List of Valid Control Field values by hex value; most common in bold:
From
Remote
From
Master
Function
00
80
ACK
01
81
NACK
Failed transaction
0B
8B
Link Status Reply
No flow Control
10
90
ACK
Frame accepted, no more buffers left
11
91
NACK
Frame not accepted, no buffers available
1B
9B
Link Status Reply
No buffers available
40
C0
RESET LINK
41
C1
Reset User Process
44
C4
Unconfirmed User Data
49
C9
Link Status Request
52
D2
Test Link
FCB = 0
53
D3
Confirmed User Data
FCB = 0
60
E0
RESET LINK
FCB = 1 ignored
61
E1
Reset User Process
FCB = 1 ignored
64
E4
Unconfirmed User Data
FCB = 1 ignored
69
E9
Link Status Request
FCB = 1 ignored
72
F2
Test Link
FCB = 1
73
F3
Confirmed User Data
FCB = 1
Other
Frame Header:
Byte
1
2
3
4
5
Name
05
64
LEN
CTRL
DEST
6
7
8
SOURCE
9
CRC
10
11
TH
Transport Header(TH): Bit 7 = FINAL, Bit 6 = FIRST
DNP3-2001 IED Certification Procedure
Subset Level 1
Page 56
Rev 2.1 – 5-July-01
DNP
APDU
APCI
DUI
Message Header
Request Header
Appl.
Ctrl
IO
DUI
Object Header
Data
IO
Object Header
Data
Response Header
Func
Code
Appl.
Ctrl
Func
Code
Internal
Indication
Object
Group
Object
Variation
Qualifier
Range
See Data Object Library
7
APCI
=
Application
Protocol
Control
Information
DUI
=
Data Unit
Identifier
IO
=
Information
Object
DNP3-2001 IED Certification Procedure
Subset Level 1
4 3
2
1
0
Depends on
Qualifier
Code
0
CLASS 1
1
ALL STATIONS
2
CLASS 2
CLASS 3
NEED TIME
LOCAL
3
SECOND OCTET
7
6
5
4
3
2
1
0
BAD FUNCTION
Application
Protocol Data
Unit
4
OUT OF RANGE
=
5
OBJECT UNKNOWN
APDU
6
ALREADY EXEC
Distributed
Network
Protocol
7
BUFFER OVERFLOW
=
5
FIRST OCTET
BAD CONFIG
DNP
0x00 Confirm
0x00 Confirm
0x01 Read
0x81 Response
0x02 Write
0x82 Unsolicited
Response
0x03 Select
0x04 Operate
0x05 Direct Operate
0x06 Direct Op, No Ack
0x07 Immediate Freeze
0x08 Immediate Freeze No Ack
0x09 Freeze and Clear
0x0A Freeze and Clear No Ack
0x0B Freeze with Time
0x0C Freeze with Time No Ack
0x0D Cold Restart
0x0E Warm Restart
0x0F Init Data to Defaults
0x10 Initialize Application
0x11 Start Application
0x12 Stop Application
0x13 Save Configuration
0x14 Enable Unsolicited Msgs
0x15 Disable Unsolicited Msgs
0x16 Assign Class
0x17 Delay Measurement
RESTART
0
DEV. TROUBLE
1
RESERVED
2
RESERVED
3
SEQUENCE
4
UNSOLICITED
FINAL
5
CONFIRM
6
FIRST
7
6
INDEX SIZE
0 – No Index, Packed
1 – 1 Octet Index
2 – 2 Octet Index
3 – 4 Octet Index
4 – 1 Octet Object Size
5 – 2 Octet Object Size
6 – 4 Octet Object Size
QUALIFIER CODE
0 – 8-Bit Start and Stop Indices
1 – 16-Bit Start and Stop Indices
2 – 32-Bit Start and Stop Indices
3 – 8-Bit Absolute Address Identifers
4 – 16-Bit Absolute Address Identifiers
5 – 32-Bit Absolute Address Identifers
6 – No Range Field (all)
7 – 8-Bit Quantity
8 – 16-Bit Quantity
9 – 32-Bit Quantity
11 – (0xB) Variable Array
INDEX SIZE (QUAL CODE = 11)
0 – Dataless Object; No Further Indexing
1 – 1 Octet Index or Identifier Size
2 – 2 Octet Index or Identifier Size
3 – 4 Octet Index or Identifier Size
Page 57
Rev 2.1 – 5-July-01
Distributed Network Protocol (DNP3-2001)
DNP3-2001
Intelligent Electronic Device (IED)
Certification Procedure
Subset Level 2
Version 2.1
5-July-01
Disclaimer Statement
DNP User Group documents and publications are not consensus documents. Information contained in this and other works
has been obtained from sources believed to be reliable, and reviewed by credible members of the DNP User Group and/or
the DNP User Group Technical Committee. Neither the DNP Users Group nor any authors/developers of DNP
documentation guarantee, and each such person expressly disclaims responsibility for ensuring, the accuracy or
completeness of any information published herein, and neither the DNP Users Group nor its authors/developers shall be
responsible for any errors, omissions, or damages arising out of use of this document.
Likewise, while the author/developer and publisher believe that the information and guidance given in this work serves as
an enhancement to users, all parties must rely upon their own skill and judgment when making use of it. Neither the author
nor the publisher assumes any liability to anyone for any loss or damage caused by any error or omission in the work,
whether such error or omission is the result of negligence or any other cause. Any and all such liability is disclaimed.
This statement was developed by the DNP User Group Technical Committee and represents the considered judgment of a
group of software developers with expertise in the subject field. The DNP User Group is a global forum for users and
implementers of the protocol and promotes implementers and developer information and interaction exchange. This work
is published with the understanding that the DNP User Group and its authors/developers are supplying information through
this publication, not attempting to render engineering or other professional services. If such services are required, the
assistance of an appropriate professional should be sought. The DNP User Group is not responsible for any statements
and/or opinions advanced in this publication.
NOTICE OF RIGHTS - DNP USERS GROUP
The contents of this manual are the property of the DNP Users Group. Revisions or additions to the definition and
functionality of the DNP Protocol cannot be made without express written agreement from the DNP Users Group or its duly
authorised party. In addition, no part of this document may be altered or revised or added to in any form or by any means,
except as permitted by written agreement with the DNP Users Group or a Party duly authorised by the DNP Users Group.
The DNP Users Group has made every reasonable attempt to ensure the completeness and accuracy of this document.
However, the information contained in this manual is subject to change without notice, and does not represent a
commitment on the part of the DNP Users Group. An update program for DNP documents is provided upon request by the
DNP Users Group.
TRADEMARK NOTICES
DNP is a trademark of the DNP Users Group. Any brand and product names mentioned in this document are trademarks or
registered trademarks of their respective companies.
Copyright  2001 DNP Users Group. All rights reserved.
Page ii
Rev 2.1 – 5-July-01
DNP3-2001 IED Certification Procedure
Subset Level 2
Revision History
Date
18-Jan-99
15-Dec-99
Version
1.00
1.01
Sections affected
ALL
see errata sheet for 1.00
10-July-00
2.00
5-July-01
2.1
8.11.1.1
8.11.2.5.9
8.6.5.1
8.6.5.4
8.2.1.1
8.2.1.2.11 - 15
8.4.1.1
8.4.1.2.8 - 12
6
6.6.2.5
8.2.1.2.10, step 1
8.4.1.2.7, step 1
8.6.5.4
8.2.5
8.2.1.1, 8.2.1.2.3,
8.2.2.1, 8.2.2.2.2,
8.4.1.1, 8.4.1.2.3,
8.4.2.1, 8.4.2.2.2
8.2.4.1 - 8.2.4.2,
8.4.4.1 - 8.4.4.2
Section 9, Appendices A
and B
DNP3-2001 IED Certification Procedure
Subset Level 2
Reason for change
Initial Release
Fixes inconsistencies and errors
Designates protocol as DNP3-1999 (formerly DNP V3.00 with
extensions)
Added required parameter - maximum number of unsolicited retries
Added test procedure from TB9912-002
Added desired response to addresses 0xFFFE and 0xFFFD
Added test procedure from TB9912-003
Added requirements for Control SBO retries
Added test procedures from TB2000-002
Added requirements for Analog Output SBO retries
Added test procedures from TB2000-002
Removed reference to function code 1
Removed function code 0xD1 from table
Replace "end testing of Binary Output, SBO" with "skip this section"
Replace "end testing of Analog Output, SBO" with "skip this section"
Added step 2 - "Issue a link reset using link control block 0xC0"
Added test procedure from TB2000-006
Added status code in error response as required in TB2001-01
Added test procedures from TB2001-001
Removed; the information required for these sections is not available
and may not be for some time.
Page iii
Rev 2.1 – 5-July-01
Contents
1
2
3
4
5
6
7
8
Overview
1.1
Protocol specification
Notes
Definitions
3.1
General
3.2
Internal Indications
3.3
Error Responses
3.4
Changes or Events
3.4.1
§ Rules
Reference Documents
Pretest Review
5.1
Device Profile Review
5.2
Equipment Review
Link Layer
6.1
Reset Link and Passive Confirm support
6.1.1
Desired Behavior
6.1.2
Test Procedure
6.2
Test Link
6.2.1
Desired Behavior
6.2.2
Test Procedure
6.3
Request Link Status
6.3.1
Desired Behavior
6.3.2
Test Procedure
6.4
Test Retries
6.4.1
Desired Behavior
6.4.2
Test Procedure
6.5
§ DIR and FCV Bits
6.5.1
Desired Behavior
6.5.2
Test Procedure
6.6
Data Link Rejects Invalid Frames
6.6.1
Desired Behavior
6.6.2
Test Procedure – Primary Frames
6.6.2.1 Invalid Start Octets
6.6.2.2 Invalid Primary Function Code
6.6.2.3 Invalid Destination Address
6.6.2.4 Invalid CRC
6.6.2.5 § Invalid FCV
6.6.3
Test Procedure – Secondary Frames
6.6.3.1 Invalid Start Octets
6.6.3.2 Invalid Secondary Function Code
6.6.3.3 Invalid Destination Address
6.6.3.4 Invalid CRC
Transport Layer
7.1
Desired Behavior
7.2
Test Procedure
Application Layer
8.1
Binary Output Status
8.1.1
Desired Behavior
8.1.2
Test Procedure
8.2
Binary Outputs
8.2.1
Select Before Operate
8.2.1.1 Desired Behavior
DNP3-2001 IED Certification Procedure
Subset Level 2
1
1
1
3
3
3
3
4
4
5
5
5
5
6
6
6
6
7
7
7
7
7
7
8
8
8
8
8
9
9
9
9
10
10
10
10
11
11
11
12
12
12
13
13
13
14
14
14
14
14
15
15
Page v
Rev 2.1 – 5-July-01
8.2.1.2 Test Procedure
8.2.1.2.1 Binary Output, SBO, 0x28
8.2.1.2.2 Binary Output, SBO, 0x17
8.2.1.2.3 Binary Output, SBO, To Uninstalled Point
8.2.1.2.4 Binary Output, SBO, Execute Issued After Timeout
8.2.1.2.5 Binary Output, SBO, Execute to Different Point Than Select
8.2.1.2.6 Binary Output, SBO, Execute On Time does not match Select On Time
8.2.1.2.7 Binary Output, SBO, Execute Off Time does not match Select Off Time
8.2.1.2.8 Binary Output, SBO, Select using a supported Control Code, Execute using a different Control
Code
17
8.2.1.2.9 Binary Output, SBO, Select 0x28, Execute 0x17
8.2.1.2.10 Binary Output, SBO, Configurable Device
8.2.1.2.11 Binary Output, SBO, Same Sequence Number Select Retries
8.2.1.2.12 Binary Output, SBO, Incrementing Sequence Number Select Retries
8.2.1.2.13 Binary Output, SBO, Same Sequence Number Operate Retries
8.2.1.2.14 Binary Output, SBO, Incrementing Sequence Number Operate Retries
8.2.1.2.15 Binary Output, SBO, Sequence number checking
8.2.2
Direct Operate with Acknowledge
8.2.2.1 Desired Behavior
8.2.2.2 Test Procedure
8.2.2.2.1 Binary Output, Direct Operate
8.2.2.2.2 Binary Output, Direct Operate to Uninstalled Point
8.2.2.2.3 Binary Output, Direct Operate, Configurable Device
8.2.3
Direct Operate, No Acknowledge
8.2.3.1 Desired Behavior
8.2.3.2 Test Procedure
8.2.3.2.1 Binary Output, Direct Operate, No Acknowledge
8.2.3.2.2 Binary Output, Direct Operate, No Acknowledge, to an Uninstalled Point
8.2.3.2.3 Binary Output, Direct Operate, No Acknowledge, Configurable Device
8.2.4
Multiple Object Requests
8.2.4.1 Desired Behavior
8.2.4.2 Test Procedure
8.2.5
Control Code Support
8.2.5.1 Desired Behavior
8.2.5.2 Test Procedure
8.2.5.2.1 Binary Output, Complementary Function Support
8.2.5.2.2 Binary Output, Single Function Support
8.3
Analog Output Status
8.3.1
Desired Behavior
8.3.2
Test Procedure
8.4
Analog Outputs
8.4.1
Select Before Operate
8.4.1.1 Desired Behavior
8.4.1.2 Test Procedure
8.4.1.2.1 Analog Output, SBO, 0x28
8.4.1.2.2 Analog Output, SBO, 0x17
8.4.1.2.3 Analog Output, SBO, to Uninstalled Point
8.4.1.2.4 Analog Output, SBO, Execute Issued After Time-out
8.4.1.2.5 Analog Output, SBO, Execute Value does not match Select Value
8.4.1.2.6 Analog Output, SBO, Select 0x28, Execute 0x17
8.4.1.2.7 Analog Output, SBO, Configurable Device
8.4.1.2.8 Analog Output, SBO, Same Sequence Number Select Retries
8.4.1.2.9 Analog Output, SBO, Incrementing Sequence Number Select Retries
8.4.1.2.10 Analog Output, SBO, Same Sequence Number Operate Retries
8.4.1.2.11 Analog Output, SBO, Incrementing Sequence Number Operate Retries
8.4.1.2.12 Analog Output, SBO, Sequence number checking
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8.4.2
Direct Operate with Acknowledge
8.4.2.1 Desired Behavior
8.4.2.2 Test Procedure
8.4.2.2.1 Analog Output, Direct Operate
8.4.2.2.2 Analog Output, Direct Operate, to Uninstalled Point
8.4.2.2.3 Analog Output, Direct Operate, Configurable Device
8.4.3
Direct Operate, No Acknowledge
8.4.3.1 Desired Behavior
8.4.3.2 Test Procedure
8.4.3.2.1 Analog Output, Direct Operate, No Acknowledge
8.4.3.2.2 Analog Output, Direct Operate, No Acknowledge, to an Uninstalled Point
8.4.3.2.3 Analog Output, Direct Operate, No Acknowledge, Configurable Device
8.4.4
Multiple Object Requests
8.4.4.1 Desired Behavior
8.4.4.2 Test Procedure
8.5
Class Data
8.5.1
Class 0
8.5.1.1 Desired Behavior
8.5.1.2 Test Procedure
8.5.2
Class 1
8.5.2.1 Desired Behavior
8.5.2.2 Test Procedure
8.5.2.2.1 Class 1 Data, 0x06
8.5.2.2.2 Class 1 Data, 0x07
8.5.2.2.3 Class 1 Data, 0x08
8.5.2.2.4 § Class 1 Data Without Confirm
8.5.3
Class 2
8.5.3.1 Desired Behavior
8.5.3.2 Test Procedure
8.5.3.2.1 Class 2 Data, 0x06
8.5.3.2.2 Class 2 Data, 0x07
8.5.3.2.3 Class 2 Data, 0x08
8.5.3.2.4 § Class 2 Data Without Confirm
8.5.4
Class 3
8.5.4.1 Desired Behavior
8.5.4.2 Test Procedure
8.5.4.2.1 Class 3 Data, 0x06
8.5.4.2.2 Class 3 Data, 0x07
8.5.4.2.3 Class 3 Data, 0x08
8.5.4.2.4 § Class 3 Data Without Confirm
8.5.5
Multiple Object Request
8.5.5.1 Desired Behavior
8.5.5.2 Test Procedure
8.5.5.2.1 Multiple Object Request, Class 1, 2, and 3
8.5.5.2.2 Multiple Object Request, Class 1, 2, 3, and 0
8.5.6
Class Assignment Verification
8.5.6.1 Desired Behavior
8.5.6.2 Test Procedure
8.6
Indications
8.6.1
Restart
8.6.1.1 Desired Behavior
8.6.1.2 Test Procedure
8.6.2
Bad Function
8.6.2.1 Desired Behavior
8.6.2.2 Test Procedure
DNP3-2001 IED Certification Procedure
Subset Level 2
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8.6.3
Object Unknown
8.6.3.1 Desired Behavior
8.6.3.2 Test Procedure
8.6.4
Local
8.6.4.1 Desired Behavior
8.6.4.2 Test Procedure for Devices with Global Remote Supervisory Control
8.6.4.3 Test Procedure for Devices with Individual Remote Supervisory Control
8.6.5
Broadcast Address and All Stations Indication
8.6.5.1 Desired Behavior
8.6.5.2 § Test Procedure
8.6.5.3 Test Procedure
8.6.5.4 § Test Procedure, Confirmed Response Options
8.6.6
Buffer Overflow
8.6.6.1 Desired Behavior
8.6.6.2 Test Procedure
8.6.6.2.1 Buffer Overflow, Binary Input Change Event Buffers
8.6.6.2.2 Buffer Overflow, Analog Input Change Event Buffers
8.6.6.2.3 Buffer Overflow, Binary Counter Change Event Buffers
8.7
Time
8.7.1
Delay Measurement
8.7.1.1 Desired Behavior
8.7.1.2 Test Procedure
8.7.2
Synchronization
8.7.2.1 Desired Behavior
8.7.2.2 Test Procedure
8.8
Cold Restart
8.8.1
Desired Behavior
8.8.2
Test Procedure
8.9
Application Layer Fragmentation
8.9.1
Use of FIR, FIN and SEQUENCE in Fragmentation
8.9.1.1 Desired Behavior
8.9.1.2 Test Procedure
8.9.2
§ Use of Confirmation in Fragmentation
8.9.2.1 § Desired Behavior
8.9.2.2 § Test Procedure
8.10 Multi-Drop Support
8.10.1 Desired Behavior
8.10.2 Test Procedure
8.11 Unsolicited Responses
8.11.1 Desired Behavior
8.11.1.1 Configuration
8.11.1.2 Sequence Numbers and Confirmation
8.11.1.3 Restart Behavior
8.11.1.4 Runtime Behavior
8.11.1.5 Unsolicited and Polled Responses
8.11.2 Test Procedure
8.11.2.1 Unsolicited Response Configuration/Startup
8.11.2.2 Unsolicited Response - Class 1 Data
8.11.2.3 Unsolicited Response - Class 2 Data
8.11.2.4 Unsolicited Response - Class 3 Data
8.11.2.5 Unsolicited and Polled Responses
8.11.2.5.1 Transmits data-filled unsolicited responses
8.11.2.5.2 Clears transmitted data upon confirmation
8.11.2.5.3 Processes non-READ requests immediately
8.11.2.5.4 Defers READ requests until after confirmation received
8.11.2.5.5 Defers READ requests until after confirmation timeout
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8.11.2.5.6 Abandons READ requests upon subsequent non-READ requests
8.11.2.5.7 Abandons READ requests upon subsequent READ requests
8.11.2.5.8 Inhibits Unsolicited responses until after polled confirmation
8.11.2.5.9 Retries unsolicited responses configurable number of times
8.11.2.6 Unsolicited Responses Off
8.12 § Collision Avoidance
8.12.1 Desired Behavior
8.12.2 Test Procedure
8.13 Binary Inputs
8.13.1 Desired Behavior
8.13.2 Test Procedure
8.13.2.1 Device does not have Binary Inputs
8.13.2.2 Device has Binary Inputs
8.13.2.3 Device supports Binary Inputs, Configurable Device
8.14 Binary Input Change
8.14.1 Desired Behavior
8.14.2 Test Procedure
8.14.2.1 Device does not support Binary Input Changes
8.14.2.2 Binary Input Change, 0x06
8.14.2.3 Binary Input Change, 0x07
8.14.2.4 Binary Input Change, 0x08
8.14.2.5 § Binary Input Change Without Confirm
8.14.2.6 Binary Input Change Without Time, 0x06
8.14.2.7 Binary Input Change Without Time, 0x07
8.14.2.8 Binary Input Change Without Time, 0x08
8.14.2.9 Binary Input Change With Time, 0x06
8.14.2.10 Binary Input Change With Time, 0x07
8.14.2.11 Binary Input Change With Time, 0x08
8.14.2.12 Binary Input Change With Relative Time, 0x06
8.14.2.13 Binary Input Change With Relative Time, 0x07
8.14.2.14 Binary Input Change With Relative Time, 0x08
8.14.2.15 Binary Input Change with Relative Time, Long Interval
8.15 Common Time of Occurrence
8.15.1 Desired Behavior
8.15.2 Test Procedure
8.16 Binary Counters
8.16.1 Binary Counters, Running
8.16.1.1 Desired Behavior
8.16.1.2 Test Procedure
8.16.1.2.1 Device does not have Binary Counters
8.16.1.2.2 Device responds with Binary Counters
8.16.1.2.3 Device responds with Delta Counters
8.16.1.2.4 § Device Responds with Delta Counters, No Confirm
8.16.1.2.5 Device supports Binary Counters, Configurable Device
8.16.2 Binary Counters, Frozen
8.16.2.1 Desired Behavior
8.16.2.2 Test Procedure
8.16.2.2.1 Device does not have Frozen Counters.
8.16.2.2.2 Binary Counter, Freeze
8.16.2.2.3 Binary Counter, Freeze And Clear
8.16.2.2.4 Binary Counter, Freeze, No Acknowledge
8.16.2.2.5 Binary Counter, Freeze And Clear, No Acknowledge
8.17 Binary Counters, Event
8.17.1 Desired Behavior
8.17.2 Test Procedure
DNP3-2001 IED Certification Procedure
Subset Level 2
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8.17.2.1 Device does not support Binary Counter Events
8.17.2.2 Binary Counters, Event, 0x06
8.17.2.3 Binary Counters, Event, 0x07
8.17.2.4 Binary Counters, Event, 0x08
8.17.2.5 § Binary Counters, Event Without Confirm
8.18 Analog Input
8.18.1 Desired Behavior
8.18.2 Test Procedure
8.18.2.1 Device does not have Analog Inputs
8.18.2.2 Device has Analog Inputs
8.19 Analog Change Event
8.19.1 Desired Behavior
8.19.2 Test Procedure
8.19.2.1 Analog Input Change
8.19.2.2 § Analog Input Change, Without Confirm
8.20 Multiple Read Requests
8.20.1 Desired Behavior
8.20.2 Test Procedure
9 Appendix A – DNP Reference Sheets
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1 Overview
It is the purpose of this document to describe a set of tests that will determine an Intelligent Electronic Devices’ (IED)
compliance with the Distributed Network Protocol (formly known as DNP V3.00). This certification procedure is
designed specifically to determine an IED’s compliance to Level 2 of the Subset Definitions.
1.1
Protocol specification
The protocol is defined by the Basic 4 Document set (Link Layer, Transport Layer, Application Layer, and Subset
Definitions), Technical Notes published by the Technical Committee, and this Certification Procedure. The protocol
defined by these documents shall be denoted DNP3-2001.
Sections in this document marked with the symbol "§" constitute new requirements or clarifications beyond the Basic 4
Document set. These sections may create interoperability problems with implementations done prior to the publication
of this test procedure. However, the DNP Users' Group approved these changes at the annual 1999 meeting based on
strong recommendation from the Technical Committee. These requirements and clarifications will greatly improve
interoperability and extensive efforts have been made to minimize the impact on existing implementations.
2 Notes
1.
This procedure is an attempt to produce interoperability between Master and IED devices, although such
interoperability can NOT be guaranteed. However, it does gives reasonable assurance that Masters which can be
configured to match items in the IED Device Profile Document will interoperate.
2.
Wherever the following procedures generate a specific number of events, it is acceptable to use an alternate number
supported by the device provided that the intent of the test is still satisfied.
3.
This is not a factory acceptance test, but a protocol test. Therefore only selected outputs will be tested to verify
protocol operation.
4.
Unless otherwise specified, all Application Layer retries are disabled.
5.
If not explicitly stated all tests imply verification that all points in a normal operating state are reported with all flag
bits except the ONLINE bit clear and the ONLINE bit is set. Alternatively, verification that the object is reported
with the “without flags” variation is also implied.
6.
Sections marked with three asterisks (***) extend the requirements of the device beyond DNP3-2000.
7.
Record the point numbers used in all tests in the log.
8.
All application layer tests use unconfirmed link services using a request link control block of 0xC4 unless specified
otherwise.
9.
When time tagged events are reported the certification procedures do not measure the absolute accuracy of the
reported times. They do however verify that the reported times are updated in a reasonable manner. The Device
Profile Document specifies the accuracy with which the device measures the event. This accuracy is guaranteed by
the vendor, not the certification procedures.
10. If not explicitly stated all tests imply verification that a response to a request has the same application sequence
number as the request. If the request generates multiple application fragments also verify that the application
sequence number of each subsequent fragment increments by 1 modulo 16.
11. These tests assume that the device will only generate events as controlled by the tester, as specified in the procedure.
DNP3-2001 IED Certification Procedure
Subset Level 2
Page 1
Rev 2.1 – 5-July-01
12. It is strongly recommended that the tester run the device for a least 24 hours at some point during the testing to
insure that it does not exhibit any unusual or unexpected behavior. This is not a requirement for compliance to this
procedure.
13. Responses to all properly formed requests, must result in either the specific action or behavior described in the
protocol or in a correctly-formed, appropriate protocol error response. In addition, devices must continue to operate
without interruption or anomalous behavior in response to properly or improperly formed requests.
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DNP3-2001 IED Cer
3 Definitions
3.1
General
Master
Device that sends DNP application function codes 0-23.
Slave
Device that sends DNP application function code 0,128,129 (also known as “IED”).
Operate This is an action taken by the Slave in response to a Master DNP request. This action does not include
transmission of a response. Examples of an operation are an audible relay click, change in an LED status, or
change in the internal state of the Slave. Note that some operations are difficult to observe without intimate
knowledge of the Slave device. The inability to observe an operation does not mean that an operation failed to
take place.
Request
Any message from a Master to a Slave where a response from the Slave is expected.
Response Message from Slave caused by a Master Request. Responses are classified as follows:
•
No response: No octets are sent by Slave
•
Link only response: 10 octet message consisting of only a link layer message
•
Null Response: Message containing a 17-octet link/transport/application response with no error IIN
bits set and no application objects.
•
Normal Response: Message containing an application response which has no error IIN bits set, and has
no objects which indicate errors
•
All responses must begin with the same application sequence number as the corresponding request.
•
For Multi-fragment responses the first fragment must have the same sequence number as the request
and each subsequent fragment must increment the sequence number by 1 modulo 16.
3.2
IIN
IIN1-1
IIN1-2
IIN1-3
IIN1-4
IIN1-5
IIN1-7
IIN2-0
IIN2-1
IIN2-2
3.3
Internal Indications
Octets 3 and 4 of the application response header. Bits are named IINx-y. x=1 for first transmitted octet and 2
for second transmitted octet. y=bit number where 0=least significant bit. Refer to the Basic Four Application
Layer section 3.6 and the Subset Definitions section 4.1.1 for detailed explanations of the IIN bits. The
following is a summary of the definitions.
Class 1 event data available. Can be set at any time and does not indicate an error condition.
Class 2 event data available. Can be set at any time and does not indicate an error condition.
Class 3 event data available. Can be set at any time and does not indicate an error condition.
Time synchronization required. Can be set at any time and does not indicate an error condition.
Local mode. Set if some points are uncontrollable via DNP.
Device restart. Set only under specific conditions. Does not indicate an error condition.
Function Unknown. Generally means that the function code (octet 2 of the request header) cannot be
processed.
Object Unknown. Generally means that the function code could be processed but the object group / variation
could not be processed.
Parameter Error. Generally indicates that both the function code and object group / variation could be
processed but that the qualifier / range field is in error.
Error Responses
Error IIN bits IIN bits that indicate a request error (i.e., IIN2-0 or IIN2-1 or IIN2-2).
Error Response A response that has any or all of the Error IIN bits set which may also contain data.
DNP3-2001 IED Certification Procedure
Subset Level 2
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Unexpected Error Response
Slaves may generate responses with any or all of the following:
• unexpected bits in the IIN set
• unexpected bits in any returned flags set
• unexpected status code errors
Any unexpected responses must be noted by the tester and “explained” in the test log.
3.4
Changes or Events
This section clarifies processing rules related to the following objects.
Change Object
Name
Corresponding Static Object
Object
Name
Object
Binary Input Change
2
Binary Input
1
Counter Change Events
22
Counter
20
Frozen Counter Change Events
23
Frozen Counter
21
Analog Change Events
32
Analog Input
30
Frozen Analog Change Events
33
Frozen Analog Input
31
Table 3-1
1.
2.
3.
The term “significant change” refers to any of the synonymous terms: “event” or “change event”.
Change Objects and Static Objects are related in that a significant change in a point’s static value results in the
creation of a corresponding Change Object entry
A significant change for a point is defined to occur:
• for a binary point, on any change in state, and
• for a numeric point, on any change in value greater than the point’s threshold
3.4.1 § Rules
A device may claim that it supports a specific Change Object if and only if processing for that Change Object can be
configured to adhere to the following rules.
1.
2.
3.
4.
Change processing must be supported for all points in the corresponding Static Object.
The determination that a point has undergone a significant change can be determined only by using information
from that point’s current or past value. Decisions based on information about any other point, directly or indirectly,
are explicitly forbidden.
For numeric Change Objects, the Device Profile must clearly specify the algorithm used for each point or set of
points that specifies how the deadband(s) for those points are determined.
All changes must be returned to a host that issues a request for any specific Change Object, limited only by qualifier
and range codes in the request.
Some devices may decide to limit the set of points included in Change Object processing (in violation of rule 1), or to
invoke a more complicated algorithm for determining a significant change (in violation of rule 2). While these
implementations may be useful in specific instances, such devices may not check compliance with the corresponding
Change Object in their Device Profile Documentation unless the device is configurable to conform to the rules above.
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DNP3-2001 IED Cer
4 Reference Documents
•
•
•
•
•
DNP Version 3.00 Data Link Layer
DNP Version 3.00 Transport Functions
DNP Version 3.00 Application Layer
DNP Version 3.00 Data Object Library Layer
DNP Version 3.00 Subset Definitions Version 2.00 (§ Version 3.00)
5 Pretest Review
Before testing proceeds it is necessary to review documentation and equipment supplied by the vendor for completeness
and appropriateness to the application. In particular the vendor must have provided the test facility with the following
items.
• Device Profile Document
• Device to be tested
• Wiring Diagrams for
• Power
• Communications (e.g. RS232, RS485, Bell 202, IEEE 802.3)
• Input connections
5.1
Device Profile Review
Before connecting any equipment the Device Profile should be carefully reviewed. This document describes the vendors’
specification of the behavior of the device. This behavior should be compared to Level 2 requirements and any
discrepancies resolved before testing proceeds. Specifically the Device Profile should indicate that the device:
•
•
Responds to all Level 2 requests that a slave device is required to parse.
Responds to Level 2 requests only with Objects/Variations and Qualifiers that a Level 2 master is required to parse.
If a device generates any response requiring a higher level master to parse it, the following actions should be taken:
•
•
•
Testing can continue.
It must be noted in the test results that the device is Level 2 compliant for requests only.
The required Master Level must be noted in the test results.
5.2
Equipment Review
Before testing proceeds, the device will be examined to insure the proper equipment is available for the following:
• Physical interfaces present and compatible.
• Wiring diagrams and equipment necessary for Input stimulation.
• Input power specifications.
• If it is not readily apparent whether an output point has operated, the vendor must supply to the tester a point number
and method to determine whether or not a binary control and/or analog output has operated.
A manufacturer’s representative should be available by phone to answer questions during the testing of the device.
DNP3-2001 IED Certification Procedure
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6 Link Layer
Any DNP device is required to passively implement all link layer services. Specifically, this means that a device need
not request link layer service but must support any services requested by another device. For example:
• A device can choose not to request link layer confirms but MUST respond with a link layer confirm if requested to
do so.
• A device can choose not to request link layer reset if it is using unconfirmed link services but MUST respond with a
link layer confirm if a link layer reset is requested.
• § A device must respond to all unconfirmed link requests (i.e. function codes 0, 4, 9) without a preceding link reset.
The following tests are designed to verify this functionality.
6.1
Reset Link and Passive Confirm support
6.1.1 Desired Behavior
•
•
•
•
•
•
The Device under test (DUT) must respond to a link reset with a link confirm.
DUT must respond to application layer data requests using unconfirmed link services without requiring a link reset.
DUT must not respond to application layer data requests using confirmed link services without a preceding link
reset.
DUT must respond to application layer data requests using confirmed link services after a link reset has been issued.
DUT must acknowledge but not otherwise respond to requests with the wrong FCB.
DUT must issue a data link reset if transmitting requests that require a data link confirm.
6.1.2 Test Procedure
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
14.
15.
16.
17.
18.
19.
20.
21.
22.
23.
24.
25.
26.
27.
Cycle power to the DUT.
Request Class 0 data (Object 60 Variation 1) using Qualifier Code 0x06 and link control block 0xC4.
Verify that the DUT responds with a valid message.
Request Class 0 data (Object 60 Variation 1) using Qualifier Code 0x06 and link control block 0xF3.
Verify that the DUT either sends a NACK with the DFC bit clear or does not respond.
Request Class 0 data (Object 60 Variation 1) using Qualifier Code 0x06 and link control block 0xD3.
Verify that the DUT either sends a NACK with the DFC bit clear or does not respond.
Issue a link reset using link control block 0xC0.
Verify that the DUT responds with a link layer confirm (link control block 0x00).
Request Class 0 data (Object 60 Variation 1) using Qualifier Code 0x06 and link control block 0xF3.
Verify that the DUT responds with a link layer confirm and a valid application layer response.
Perform repeated requests of Class 0 data (Object 60 Variation 1) using Qualifier Code 0x06 and alternating link
control blocks 0xD3 and 0xF3.
Verify that the DUT responds with a link layer confirm and a valid application layer response for each request.
Issue a link reset using link control block 0xC0.
Verify that the DUT responds with a link layer confirm (link control block 0x00).
Request Class 0 data (Object 60 Variation 1) using Qualifier Code 0x06 and link control block 0xD3.
Verify that the DUT responds with a link layer confirm (link control block 0x00) and no application response.
Request Class 0 data (Object 60 Variation 1) using Qualifier Code 0x06 and link control block 0xF3.
Verify that the DUT responds with a link layer confirm and a valid application layer response.
Request Class 0 data (Object 60 Variation 1) using Qualifier Code 0x06 and link control block 0xF3.
Verify that the DUT responds with a link layer confirm (link control block 0x00) and no application response.
If the DUT cannot be configured to request data link confirms when transmitting, continue testing at section 6.2.
Configure the DUT to request data link confirm when transmitting.
Cycle power to the DUT.
Request Class 0 data (Object 60 Variation 1) using Qualifier Code 0x06 and link control block 0xC4.
Verify that the DUT responds by sending a data link reset (control block 0x40).
Send a data link acknowledge (control block 0x80).
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28. Verify that the DUT responds with a valid message having control block 0x73. This is the response to the Class 0
data request, including a request for data link confirm.
29. Issue a data link NACK with DFC clear (control block 0x81).
30. If the DUT then issues a data link reset (control block 0x40), respond by sending an acknowledge control block
0x80). If the DUT then repeats the Class 0 response message (control block 0x73), it has functioned correctly, and
this test is complete, continue testing at section 6.2.
31. If the DUT did not issue a link reset at step 30, steps 25 through 28 should be repeated as shown above. DUT
responses other than those of steps 26 and 28 indicate incorrect operation.
6.2
Test Link
6.2.1 Desired Behavior
•
•
•
The DUT must respond with a Link Confirm - ACK if the FCB bits are correct in the test request.
Otherwise, the DUT must respond with the last secondary confirm frame. This behavior is not tested since it was
deemed by the Technical Committee as too difficult to test in a reliable manner.
If the DUT receives a test link frame without a previous link reset, the DUT must either not respond or respond with
a NACK with DFC = 0.
6.2.2 Test Procedure
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
14.
15.
16.
Cycle power to the DUT.
Request a Link Test Frame using link control block 0xF2.
Verify that the DUT responds with a Confirm - NACK with DFC=0 (link control code 0x01) or does not respond.
Issue a Link Reset using link control block 0xC0.
Request a Link Test Frame using link control block 0xF2.
Verify that the DUT responds with a Confirm - ACK (link control code 0x00).
Request a Link Test Frame using link control block 0xD2.
Verify that the DUT responds with a Confirm - ACK (link control code 0x00).
Cycle power to the DUT.
Request a Link Test Frame using link control block 0xD2.
Verify that the DUT responds with a Confirm - NACK with DFC=0 (link control code 0x01) or does not respond.
Issue a Link Reset using link control block 0xC0.
Request a Link Test Frame using link control block 0xF2.
Verify that the DUT responds with a Confirm - ACK (link control code 0x00).
Request a Link Test Frame using link control block 0xD2.
Verify that the DUT responds with a Confirm - ACK (link control code 0x00).
6.3
Request Link Status
6.3.1 Desired Behavior
•
•
When issued a Request Link Status message, the DUT must respond with a valid Status of Link message.
The DUT must ignore FCB when FCV = 0.
6.3.2 Test Procedure
1.
2.
3.
4.
5.
Cycle power to the DUT.
Request a Link Status Frame using link control block 0xC9.
Verify that the DUT responds with a valid link status message with link control block 0x0B or 0x1B.
Request a Link Status Frame using link control block 0xE9.
Verify that the DUT responds with a valid link status message with link control block 0x0B or 0x1B.
DNP3-2001 IED Certification Procedure
Subset Level 2
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6.4
Test Retries
6.4.1 Desired Behavior
•
•
•
•
•
•
DUTs are not required to support link layer retries.
The rest of these behaviors apply only to DUTs that support link layer retries.
§ The DUT must be able to disable retries through configuration.
If the device requests a link layer confirm and does not receive it within a specified period of time (LINK
TIMEOUT), it shall retransmit the link frame. It shall do this n times where n is a specified number of retries before
aborting transmission (LINK RETRYCOUNT).
If configured to enable link layer confirms on primary transmissions, the DUT must perform retries on all
SEND/CONFIRM and REQUEST/RESPOND frames.
Both LINK TIMEOUT and LINK RETRYCOUNT must be specified in the Device Profile Document or they can
optionally be configurable parameters.
6.4.2 Test Procedure
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
14.
15.
16.
17.
18.
19.
20.
If the DUT does not support link layer confirms or link layer retries on primary transmissions, continue testing in the
next section.
Configure the device to enable link layer confirms on primary transmissions and if retries are configurable, set them
to a reasonable value.
Cycle power to the DUT.
Request Class 0 data (Object 60 Variation 1) using Qualifier Code 0x06 and link control block 0xC4.
Verify that the DUT sends a RESET LINK frame. Do not send a data link CONFIRM frame.
Verify that the DUT waits LINK TIMEOUT and then retransmits the link frame.
Verify that it repeats this exactly LINK RETRYCOUNT times.
Request Class 0 data (Object 60 Variation 1) using Qualifier Code 0x06 and link control block 0xC4.
Verify that the DUT responds with a RESET LINK frame. Send a data link CONFIRM.
Verify that the DUT sends a valid application layer response in a SEND/CONFIRM USER DATA frame. Do not
send a data link CONFIRM frame.
Verify that the DUT waits LINK TIMEOUT and then retransmits the link frame.
Verify that it repeats this exactly LINK RETRYCOUNT times.
If it is possible to cause the DUT to send TEST LINK, RESET USER PROCESS, or REQUEST LINK STATUS,
cause it to do so, but do not respond in each case. Repeat steps 11 and 12 for each of these frames that can be
generated.
Request Class 0 data (Object 60 Variation 1) using Qualifier Code 0x06 and link control block 0xC4.
Verify that the DUT responds with a RESET LINK frame. Send a data link CONFIRM.
Verify that the DUT sends a valid application layer response in a SEND/CONFIRM USER DATA frame. Do not
send a data link CONFIRM frame.
Verify that the DUT waits LINK TIMEOUT and then retransmits the link frame.
Send a data link CONFIRM.
Verify that no further retries are sent.
If it is possible to cause the DUT to send TEST LINK, RESET USER PROCESS, or REQUEST LINK STATUS,
cause it to do so, but do not respond in each case. Repeat steps 18 and 19 for each of these frames that can be
generated.
6.5
§ DIR and FCV Bits
6.5.1 Desired Behavior
•
•
The DUT must clear (set to zero) the DIR bit in each data link frame it transmits.
The DUT must set the FCV bit to zero in all frames except SEND/CONFIRM User Data and SEND/CONFIRM
Test Link. These frames are tested elsewhere.
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6.5.2 Test Procedure
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
If the DUT is capable of requesting data link confirmations, configure it to NOT request data link confirmations.
Cycle power to the DUT.
Prepare and send a READ request for Class 0 data (Object 60 Variation 1) using Qualifier Code 0x06 and a link
control block 0xC4.
Verify the response from the DUT uses data link control block 0x44 i.e. Unconfirmed User Data with the DIR bit
not set and the FCV bit not set.
If the DUT can generate RESET USER PROCESS or REQUEST LINK STATUS, cause it to do so and verify none
of these frames have the DIR or FCV bit set.
If the DUT can generate TEST LINK, cause it to do so and verify that these frames have the DIR bit clear and FCV
bit set.
If the DUT is not capable of requesting data link confirmations, no further testing is required in this section. If the
DUT is capable of requesting data link confirmations, configure it to do so.
Cycle power to the DUT.
Prepare and send a READ reques