Digital Level Sensor
5020 Modbus Translator
User’s Guide
Version – 2011.05
5020 Modbus Translator
User’s Guide
Siemens Energy, Inc.
Oil & Gas Solutions
10730 Telge Road
Houston, Texas 77095
USA
Document No. SEI-OG-DLS-004
Page 1 of 10
© Siemens AG 2011
Digital Level Sensor
5020 Modbus Translator
User’s Guide
Version – 2011.05
Table of Contents
1
OVERVIEW ........................................................................................................................................................ 3
2
INSTALLATION ................................................................................................................................................ 3
3
OPERATION....................................................................................................................................................... 3
4
SCADA CONFIGURATION ............................................................................................................................. 4
5
TROUBLESHOOTING...................................................................................................................................... 7
6
SPECIFICATIONS............................................................................................................................................. 8
7
CONTACT INFORMATION .......................................................................................................................... 10
Document No. SEI-OG-DLS-004
Page 2 of 10
© Siemens AG 2011
Digital Level Sensor
5020 Modbus Translator
User’s Guide
Version – 2011.05
1
OVERVIEW
The 5020 Modbus Translator was designed to convert ASCII protocol, from the Siemens Model 1000
digital level sensor, to Modbus RTU protocol. The Translator wires in between the SCADA unit and the
sensors (through the 1010 Barrier board, as shown in Figure 6.1). The 5020 Modbus Translator searches
for sensors connected to it at 9600 N81 baud rate (up to 16 sensors). This means it configures itself. The
Modbus data can be in 16 bit unsigned format or 32 bit floating point format.
2
INSTALLATION
Do not apply power until all connections are made.
Incoming power is connected to the SCADA side of the Translator. The sensor side is fused with a
resettable one ampere fuse. The transmit lines (TX+ TX-) from the SCADA unit connect to the receive lines
(RX+ RX-) on the Modbus Translator. TX+ connects to RX+. TX- connects to RX-. The receive lines of the
SCADA unit connect to the transmit lines on the Modbus Translator. The sensors connect in the same
manner, transmit to receive and receive to transmit.
3
OPERATION
When power is first applied to the Modbus Translator the indicator light will turn orange for five (5)
seconds (See Table 3.1). This allows the sensors to initialize. Then the indicator light will turn red
indicating that the Translator is searching for sensors. The scan starts at unit 01 at 9600 N81. This is
repeated through unit 16. Any sensors responding without errors (CRC errors, framing errors, data over
run errors, or parity errors) are stored in memory. When the scan is done the indicator light will turn green
indicating it is ready to receive data request from the SCADA unit. When the Modbus Translator is
requesting sensor data the indicator light will turn red indicating communication activity. The number of
sensors configured in the Translator can be read at holding register 43987 (address 3986). To add or
remove sensors initiate a reconfiguration scan by pressing the rescan push button on the side of the
Translator. The indicator light will turn orange for five (5) seconds, and then the rescan will start.
Table 3.1 Indicator Light Status
Light Color
Orange
Red
Green
Document No. SEI-OG-DLS-004
Meaning
5 Second delay before scanning for sensors
The Translator is communicating with sensors
The Translator is ready to receive SCADA unit data requests
Page 3 of 10
© Siemens AG 2011
Digital Level Sensor
5020 Modbus Translator
User’s Guide
Version – 2011.05
4
SCADA CONFIGURATION
The Modbus Translator to SCADA unit baud rate is at 9600 N81. There is no flow control. The receive
time out must be set higher than 3 seconds. Write functions are given in Table4.1. The read function (03)
is referenced in Table 4.2. A complete register map is provided in Table 4.3. The Modbus status codes are
provided in Table 4.4. The sensor error codes are referenced in Table 4.5. Registers are unsigned integer
16 bit (or 32 bit floating point IEEE for level and temperature only). To get the address, subtract 40001
from the registers.
Table 4.1 Modbus Write Registers
Description
Register
Address
Assign Translator unit number
Set Translator to 16/32 bit mode
40107
40108
106
107
No.
Registers
1
1
Notes
Default value is 1
Default setting is 16 bit mode.
Writing a value of 1008 will set the
32 bit floating point (IEEE) mode.
Writing a value of 1007 will set the
16 bit unsigned mode.
Warning: 32 bit mode sends back one more register for each level. Do not set to 32 bit mode if your
SCADA system can not read floating point numbers. In 32 bit mode, if a read for multiple sensors is
performed, the translator can only send back data from 14 sensors in a single read. This is due to the
extra registers being sent back in 32 bit mode only (Modbus protocol rules limit this).
Table 4.2 Modbus Read Holding Registers – Function 03
Description
Register
Address
Read number of configured
sensors
Reserved
Read Translator unit number
43987
3986
No.
Registers
1
43988
43989
3987
3988
0
1
Read Translator version
Beginning of sensor data
43990
43991
3989
3990
1
1-96
Document No. SEI-OG-DLS-004
Page 4 of 10
Notes
Default value is 1. A wildcard
access can be used if the unit
number is unknown by using 30
as the unit number.
Each sensor contains one block of
six registers. Individual registers
can be polled from each block by
addressing the appropriate
holding register for a sensor.
Multiple sensors can be read with
number of registers to read set at
multiples of 6. The maximum is 96
(16 sensors X 6). In 32 bit mode
the maximum is 83 due to Modbus
protocol limits. Refer to the
register map in Table 4 for a
complete list of the sensor data
© Siemens AG 2011
Digital Level Sensor
5020 Modbus Translator
User’s Guide
Version – 2011.05
Table 4.3 Sensor Register Map
Level Sensor Address
Description
Unit number
Float 1 (top float)
Float 2 (bottom float)
Temperature
Status register
Sensor error codes
Model 1000 Digital Level Sensor
U01
U02
Register Address Register Address
43991
43997
3990
3996
U03
Register
44003
Address
4002
U04
Register
44009
Address
4008
44004
44005
44006
44007
44008
4003
4004
4005
4006
4007
44010
44011
44012
44013
44014
4009
4010
4011
4012
4013
U07
Register
44027
44028
44029
44030
44031
44032
Address
4026
4027
4028
4029
4030
4031
U08
Register
44033
44034
44035
44036
44037
44038
Address
4032
4033
4034
4035
4036
4037
U11
Register
44051
44052
44053
44054
44055
44056
Address
4050
4051
4052
4053
4054
4055
U12
Register
44057
44058
44059
44060
44061
44062
Address
4056
4057
4058
4059
4060
4061
U15
Register
44075
44076
44077
44078
44079
44080
Address
4074
4075
4076
4077
4078
4079
U16
Register
44081
44082
44083
44084
44085
44086
Address
4080
4081
4082
4083
4084
4085
Level Sensor Address
Description
Unit number
Float 1 (top float)
Float 2 (bottom float)
Temperature
Status register
Sensor error codes
43992
43998
3991
3997
43993
43999
3992
3998
43994
44000
3993
3999
43995
44001
3994
4000
43996
44002
3995
4001
Model 1000 Digital Level Sensor
U05
U06
Register Address Register Address
44015
44021
4014
4020
44016
44022
4015
4021
44017
44023
4016
4022
44018
44024
4017
4023
44019
44025
4018
4024
44020
44026
4019
4025
Model 1000 Digital Level Sensor
U09
U10
Register Address Register Address
44039
44045
4038
4044
44040
44046
4039
4045
44041
44047
4040
4046
44042
44048
4041
4047
44043
44049
4042
4048
44044
44050
4043
4049
Model 1000 Digital Level Sensor
U13
U14
Register Address Register Address
44063
44069
4062
4068
44064
44070
4063
4069
44065
44071
4064
4070
44066
44072
4065
4071
44067
44073
4066
4072
44068
44074
4067
4073
Description
Unit number
Float 1 (top float)
Float 2 (bottom float)
Temperature
Status register
Sensor error codes
Notes to Table 4
Level Sensor Unit Address
Top float for level sensor. Implied decimal place at second digit (16 bit)
Bottom float for level sensor. Implied decimal place at second digit (16 bit)
Fluid Temperature for level sensor (located 12 inchs from bottom of sensor)
Contains status of the data exchange for level sensor. (See Table 5)
Sensor error codes for level sensor (See Table 6)
Level Sensor Address
Description
Unit number
Float 1 (top float)
Float 2 (bottom float)
Temperature
Status register
Sensor error codes
Level Sensor Address
Description
Unit number
Float 1 (top float)
Float 2 (bottom float)
Temperature
Status register
Sensor error codes
Document No. SEI-OG-DLS-004
Page 5 of 10
© Siemens AG 2011
Digital Level Sensor
5020 Modbus Translator
User’s Guide
Version – 2011.05
Table 4.4 Modbus Unit Status Codes
Status Code
Indication
1
Communication error with
sensor (Parity, data over run,
or framing
error).
Communication error with
sensor (CRC error).
Sensor time-out Error (Sensor
didn't reply).
Sensor returned error code in
sensor error holding register
2
4
8
Table 4.5 Sensor Error Codes
Error Code
Indication
0
No Errors
1
Can't resolve level reading or no float is detected
2
One float is out of range on a two float sensor
4
Too many groups
8
Not used
16
Transmit to slave processor for level failed
32
Transmit to slave processor for temperature failed
64
Receive of level from slave processor failed
128
Receive of temperature from slave processor failed
Note for advanced users
Writing 1007 at register address 107 will set the device registers that hold top float, bottom float and
temperature to 16 bits unsigned integer. Writing 1008 will set the device registers that hold top float,
bottom float and temperature to 32 bits floating point format.
Document No. SEI-OG-DLS-004
Page 6 of 10
© Siemens AG 2011
Digital Level Sensor
5020 Modbus Translator
User’s Guide
Version – 2011.05
5
TROUBLESHOOTING
This section provides guidance in correcting problems which may be encountered during installation and
operation. Refer to Table 5.1 for possible solutions when errors occur.
Table 5.1 Solutions to Sensor Error Codes
Problem
SCADA unit time out
Possible Solution
Increase the SCADA unit receive time out
Translator indicates zero sensors
Check the connections to the sensors. Check the
voltage on the sensor side of the Translator. The
sensors require a minimum of 8 volts at the sensor.
If the voltage is below this and the voltage on the
SCADA side is higher then the 1 ampere fuse
maybe overloaded. Disconnect power from the
SCADA side of the Translator and look for a short,
or a reason for over load on the sensor side. If all
connections and voltages appear to be correct,
then try swapping the transmit and receive lines to
the sensors, and rescan for sensors.
SCADA unit has a receive timeout, but Increase the
SCADA unit receive time out. data does not clear in
registers(i.e., old data is still in data registers)
Increase the SCADA unit receive time out
Indicator light is not green, orange, or red
Check for correct voltage on the SCADA side of the
Translator. The minimum voltage for the Translator
is 9 volts
SCADA unit indicates a CRC error
Make sure the RX+ and TX+ are connected
together. Not RX+ to TX-. Also this can be caused
by the Translator being set to 32 bit mode when
trying to read 16 bit data. If you are reading
16 bit data and get CRC errors try writing the data
1007 at register 43108 (address 107).
This will set the Translator back to 16 bit unsigned
mode.
Status code 1 (communications error)
Make sure that the sensor is configured for 9600
baud and no parity. Check the wiring of the sensor
to the Translator. Make sure that the RX+ and TX+
are connected together. Do not connect RX+ to TX. Make sure that the communication lines are not
shorted together.
Document No. SEI-OG-DLS-004
Page 7 of 10
© Siemens AG 2011
Digital Level Sensor
5020 Modbus Translator
User’s Guide
Version – 2011.05
Problem
Status code 2 (communications error-CRC)
Possible Solution
Make sure that the RX+ and TX+, and RX- and TXare connected together. Do not connect RX+ to TX. Make sure that the communication lines are not
shorted together.
Status code 3 (time-out error)
A configured sensor in the Translator has been
disconnected, or failed to respond. Check
for broken wires. If this sensor has been removed
then rescan for sensors. Measure the voltage
at the sensor. There should be at least 8 volts at
the sensor fuse board
Status code 8 (register error)
Amy value other than 1 or 2 means the sensor
need to be retuned for repair.
6
SPECIFICATIONS
Power requirements
17VDC maximum. 9VDC minimum (sensors require 8 volts minimum
at the sensor).
Power consumption
18mA in idle mode (LED green), 30mA maximum (LED orange).
Power limit
1 Ampere maximum. This is controlled by a resettable fuse
Operating temperature range
-40°C to 60°C
Document No. SEI-OG-DLS-004
Page 8 of 10
© Siemens AG 2011
Digital Level Sensor
5020 Modbus Translator
User’s Guide
Version – 2011.05
Figure 6.1 Modbus Translator Arrangement
Document No. SEI-OG-DLS-004
Page 9 of 10
© Siemens AG 2011
Digital Level Sensor
5020 Modbus Translator
User’s Guide
Version – 2011.05
7
CONTACT INFORMATION
For further information or for assistance, please contact:
Siemens Energy, Inc.
Oil & Gas Solutions
10730 Telge Road
Houston, TX 77095
Phone: +1 (888) 856-4528 or +1 (281) 856-4530
Email: oilandgaslcm.energy@siemens.com
Web site: www.siemens.com/energy/dls
Document No. SEI-OG-DLS-004
Page 10 of 10
© Siemens AG 2011