EX206
TRANSDUCER
EXCITATION,
SIGNAL
CONDITIONING
AND TERMINATION
PANEL
This Instruction Manual is supplied with the EX206 Transducer Excitation and Signal Conditioning Panel to provide the
user with sufficient information to utilise the purchased product in a proper and efficient manner. The information
contained has been reviewed and is believed to be accurate and reliable, however Amplicon Liveline Limited accepts
no responsibility for any problems caused by errors or omissions. Specifications and instructions are subject to change
without notice.
Model EX206 Instruction Manual Part Nº 859 561 34 Issue A3
© Amplicon Liveline Limited
Prepared by Technical Publications
Approved for issue by A.S. Gorbold, Operations Director
EX206
EX206 TRANSDUCER EXCITATION AND SIGNAL CONDITIONING PANEL
LIST OF CONTENTS
SECTION
SUBJECT
PAGE
1
1.1
1.2
1.3
1.4
1.5
1.5.1
1.5.2
1.5.3
1.6
1.6.1
1.7
1.7.1
1.7.2
INTRODUCTION
General Description
Features of the EX206 Panel
What the Package Contains
The Amplicon Warranty Covering the EX206
Prerequisites for installing the EX206
Host Computer Requirements.
Data Acquisition Board
Interconnection Cables
Technical Outline of EX206 Panel
EX206 Block Diagram
Contacting Amplicon Liveline Limited for Technical Support or Service
Technical Support
Repairs
1
1
2
3
3
3
4
4
4
5
6
9
9
9
2
2.1
2.1.1
2.1.2
2.1.3
2.1.4
2.2
2.3
2.4
2.4.1
2.4.2
2.5
2.6
2.6.1
2.6.2
2.7
2.8
2.9
2.10
2.10.1
2.10.2
2.11
2.12
2.13
GETTING STARTED
Assembling and Mounting the EX206 Panel
Assembling the Carrier Frame
Stacking the Panels
Mounting the Panel on a DIN Carrier Rail
Mounting the Board or Board Stack on a Flat Panel
Quick Start
Setting Up the EX206
On-board Voltage Reference
Selecting the Reference Voltage
Re-calibration of the Reference Voltage
On-board Cold Junction Temperature Reference
Auxiliary Power Supplies
The Need for Auxiliary Power Supplies
Configuration of the EX206 for Auxiliary Power
Jumper Setting for Analog or Digital Trigger Source
Selecting the Trigger Set-Point Source
Selecting the Analog Trigger Signal Source
Setting the Transducer Excitation Parameters
Voltage or Current Selection
Selecting the Value of the Voltage or Current Excitation
Mounting the Bridge Completion Modules
Mounting the Analog Input Signal Conditioning Modules
Summary of Factory Settings for Jumpers and Pluggable Components
10
10
10
11
11
12
12
16
16
16
18
18
19
19
21
22
22
23
24
24
25
25
26
27
3
3.1
3.2
3.2.1
3.2.2
3.2.3
3.2.4
3.2.5
3.2.6
3.3
MAKING THE CONNECTIONS
Positioning the Expansion Panels
Panel Interconnect Cables
Control Interconnect Cables
Signal Interconnect Cables
Digital Input/Output Cable
Auxiliary Power Cables
User Manufacture of Interconnect Cables
Screened Cables and Chassis Ground Connections
Analog Signal Input Connections
28
28
28
28
29
29
30
30
30
31
EX206
3.3.1
3.3.2
3.3.3
3.4
3.4.1
3.4.2
3.4.3
3.4.4
3.4.5
3.5
3.6
3.7
The Terminal Connectors
Typical Input Channel Connections
IMPORTANT NOTES - Please read before making connections
Signal Sources and Their Methods of Connection
Unused Inputs
Fully Floating Differential Source
Differential Signal Source
Single-ended Signal Source
Multiple Single-ended Signal Source
Control Input/Output Connections
Trigger Input/Output Connections
Digital Input/Output Connections
32
32
33
35
35
35
36
37
37
38
38
39
4
4.1
4.1.1
4.1.2
4.1.3
4.2
4.2.1
4.2.2
4.2.3
4.2.4
4.3
4.3.1
ANALOG SENSOR AND INPUT SIGNAL CONDITIONING
Transducer Connection Configuration
Excitation Configuration
Bridge Completion Header Modules
Signal Conditioning Header Modules
Standard Signal Conditioning Modules
Fitting the Signal Conditioning Modules
Thermocouple Input Module.
4 - 20 mA Current Input Module.
Multiplexer Protection Module.
Customised Signal Conditioning Modules
Typical Examples of Customised Signal Conditioning Modules.
40
40
40
41
43
43
44
45
45
46
47
48
5
5.1
5.1.1
5.1.2
5.2
PROGRAMMING_THE_ANALOG_TRIGGER
PC226 Tools Software
Library Function
Example Programs
DART200 for the PC226
52
53
53
54
6
USER’S NOTES
55
LIST OF APPENDICES
SECTION
TITLE
PAGE
APPENDIX A
APPENDIX B
APPENDIX C
APPENDIX D
APPENDIX E
TECHNICAL SPECIFICATIONS
ANALOG CHANNELS ADDRESS LIST
TRIGGER LEVEL SETTINGS LIST
GLOSSARY OF TERMS
ASSEMBLY DRAWING
EX206
i
viii
ix
x
xiv
LIST OF FIGURES
FIGURE
TITLE
PAGE
Figure 1
Figure 2
Figure 3
Figure 4
Figure 5
Figure 6
Figure 7
Figure 8
Figure 9
Figure 10
Figure 11
Figure 12
Figure 13
Figure 14
Figure 15
Figure 16
Figure 17
Figure 18
Figure 19
Figure 20
Figure 21
Figure 22
Figure 23
Figure 24
Figure 25
Figure 26
Figure 27
Figure 28
Figure 29
Figure 30
Figure 31
Figure 32
Figure 33
Figure 34
Figure 35
Figure 36
Figure 37
Figure 38
Figure 39
Figure 40
Figure 41
Figure 42
BLOCK SCHEMATIC OF EX206
ASSEMBLY OF THE EX206 CARRIER FRAME
STACKING EX201/EX206 EXPANSION PANELS
MOUNTING THE EX206 ON A DIN RAIL
EX206 BOARD MOUNTING DIMENSIONS
SIGNAL AND CONTROL CABLE CONNECTIONS TO PC226
SIGNAL AND CONTROL CABLE CONNECTIONS TO PC226E
CHANNEL ADDRESSES FOR A SINGLE EX206 SYSTEM
JUMPER SETTINGS FOR REFERENCE VOLTAGE SELECTION
INTERCONNECTION CABLE LENGTHS
AUXILIARY POWER SUPPLY JUMPERS
ANALOG/DIGITAL TRIGGER SOURCE JUMPER J12
SET-POINT SOURCE JUMPER J11
ANALOG TRIGGER SIGNAL SOURCE JUMPER J13
SELECTION OF VOLTAGE OR CURRENT EXCITATION
MAGNITUDE OF EXCITATION VOLTAGE OR EXCITATION CURRENT
CONTROL CONNECTOR PIN-OUTS
SIGNAL CONNECTOR PIN-OUTS
DIGITAL I/O CONNECTOR PIN-OUTS
AUXILIARY POWER CONNECTOR PIN-OUTS
OPERATING THE CAGE–CLAMP TERMINAL
CONNECTIONS TO A TYPICAL CHANNEL
LAYOUT OF USER SIGNAL INPUT/OUTPUT CONNECTIONS
LAYOUT OF USER SIGNAL INPUT/OUTPUT CONNECTIONS
CONNECTIONS TO FULLY FLOATING SOURCES
CONNECTIONS TO DIFFERENTIAL SIGNAL SOURCES
CONNECTIONS TO A SINGLE-ENDED SIGNAL SOURCE
CONNECTIONS TO A MULTIPLE SINGLE-ENDED SOURCE
BRIDGE COMPLETION COMPONENTS
BRIDGE COMPLETION MODULE ORIENTATION
SENSOR CONFIGURATIONS
SIGNAL CONDITIONING MODULE ORIENTATION
THERMOCOUPLE SIGNAL CONDITIONING MODULE
4 - 20 mA CURRENT SIGNAL CONDITIONING MODULE
MULTIPLEXER PROTECTION MODULE
GENERAL SCHEMATIC AND LAYOUT OF HEADER MODULE
GROUND REFERENCE RESISTOR
BALANCED LOW PASS FILTER
NORMAL MODE ATTENUATOR
NORMAL MODE ATTENUATOR WITH PROTECTION
COMMON MODE ATTENUATOR - VOLTAGE INPUT
COMMON MODE ATTENUATOR - CURRENT INPUT
EX206
8
10
11
11
12
13
14
15
17
20
21
22
23
23
25
25
29
29
30
30
32
33
34
35
36
36
37
37
41
42
43
44
45
46
46
48
49
49
50
50
51
51
EX206 TRANSDUCER EXCITATION, SIGNAL CONDITIONING AND TERMINATION PANEL
1
1.1
INTRODUCTION
General Description
The Amplicon 200 Series of Personal Computer based data acquisition products provides very
high performance, affordable hardware with user sympathetic software. When a large scale
data acquisition system is required, the capacity of the PC mounted hardware can be extended
by external expansion panels. An expanded system provides convenient management of large
numbers of signal cables, with low cost per channel and maintained high performance.
Various types of expansion panel are available to enhance the PC226 Data Acquisition Boards
and facilitate system implementation. The expansion panels and the host boards are fully
compatible, and a combination can be readily assembled to satisfy most data acquisition
requirements. Supplied and optional software packages are designed to embrace all
expansion combinations.
The EX206 Transducer Excitation, Signal Conditioning and Termination Panel described in this
manual provides convenient termination of all the analog and digital input/output signals and
control functions together with individual channel conditioning facilities for the analog signal
input lines and trigger control. The analog input conditioning facilities include precise voltage or
current excitation for powered transducers whose bridge circuits may be completed by user
mounted, on-board components. Plug-in header modules allow passive or active circuit
elements to be added to the differential analog signal pairs. Trigger control facilities allow the
PC226 to be triggered by a digital signal or by an analog signal passing through a programmed
set-point. Cold junction temperature measurement and voltage reference generators are
provided on-board the EX206. Power for the EX206 is normally supplied by the host PC226,
but the panel must be externally powered when the demands are high.
The other external panels available in the range include the EX205 Termination Panel and the
EX201 Analog Input Expansion Panel. The EX205 Termination Panel provides proper
termination of all the analog and digital input/output signals and control functions together with
conditioning facilities for all the I/O lines. Cold junction temperature measurement and voltage
reference generators are provided on-board the EX205. The EX205 is fully described in its
Technical Reference Manual Part Nº 859 243 84.
The EX201 provides 32 additional analog input channels, all supporting full differential
operation with termination and signal conditioning facilities. As on the EX205 and EX206, onboard cold junction temperature measurement and voltage reference generators are provided.
Up to seven EX201 expanders can be used in a PC226 based system to provide a total of 240
analog input channels. The EX201 is fully described in its Technical Reference Manual Part Nº
859 243 74.
A range of passive interconnect cables and signal conditioning header modules is also
available.
EX206
Page 1
1.2
Features of the EX206 Panel
• Designed to operate in conjunction with the PC226 and up to seven EX201 panels
• All analog input channels support full differential operation
• Signal conditioning facilities by plug-in header compatible with the EX201 and EX205
• All external signal input/output via cage-clamp terminal blocks
• Built in cold junction reference for thermocouple measurements
• On-board adjustable voltage reference on dedicated channel
• Individual, selectable, precise voltage or current excitation for each analog input channel
• Bridge completion facilities for each channel
• Configurable on a channel by channel basis to accept:
• Non-powered signal sources
• Voltage excited bridges
• Voltage excited two wire transducers
• Solid state temperature sensors
• DC excited LVDTs
• Current excited resistive sensors
• Programmable, full range, differential bipolar analog trigger on channel 0 or ±10V singleended analog trigger signal on Trigger Channel
• Analog trigger level set by programmable DAC or external voltage trigger level signal
• Trigger level DAC voltage output available as analog signal for external use
• Digital I/O and control signal termination
• Standard DIN rail industrial mounting
• Supported by PC226 software
• External, DIN rail mounted power supply available as an accessory
Page 2
EX206
1.3
What the Package Contains
The package as delivered from Amplicon Liveline Ltd. contains:-
1.
The EX206 expansion card protected by an anti-static plastic envelope.
! CAUTION
Some of the components on the board are susceptible to electrostatic discharge, and
proper handling precautions should be observed. As a minimum, an earthed wrist strap
must be worn when handling the EX206 outside its protective bag.
Full static handling procedures are defined in British Standards Publication
BSEN100015/BSEN100015-1:1992.
When removed from the bag, inspect the panel for any obvious signs of damage and
notify Amplicon if such damage is apparent. Do not connect a damaged EX206 into
circuit. Keep the protective bag for possible future use in transporting the board.
2.
A kit of parts for mounting the board on a DIN rail or panel.
3.
This EX206 Instruction Manual. (Amplicon part number 859 561 34).
Any additional accessories (interconnection cables, header assemblies etc.) may be packed
separately.
1.4
The Amplicon Warranty Covering the EX206
This product is covered by the warranty as detailed in the Terms and Conditions stated in the
current Amplicon Liveline catalogue.
Adding option modules, changing jumper settings or opening drill points in accordance with the
guidelines given in this manual will not void this warranty unless any damage is a direct
consequence of mishandling.
DO NOT MAKE ANY MODIFICATIONS TO A PRODUCT THAT IS ON EVALUATION.
1.5
Prerequisites for installing the EX206
Prerequisites for installing the EX206 Transducer Excitation, Signal Conditioning and
Termination Panel include the host computer, a data acquisition board and appropriate cables.
These requirements are outlined in 1.5.1 to 1.5.3 below.
EX206
Page 3
1.5.1
Host Computer Requirements.
When installing an EX206 Panel with other expansion panels and a PC226 Data Acquisition
Board, ensure that the host computer has sufficient capacity. Take into account other boards
or adapters that may be installed in the computer when assessing physical space, address
space in the I/O map, interrupt levels and the power requirements. A suitable host computer
configuration is:
• IBM© or fully compatible PC/AT running Windows 3.1 or above, a 3 1/2" HD
floppy disk drive and a hard disk drive.
• One free full length I/O board slot with AT bus connectors for the PC226
• One additional connector slot for digital I/O cable.
• Sufficient power available. +5 V at 3 A is sufficient for a single expanded 200
Series Data Acquisition system. (Expansion panels may be separately
powered if PC power capacity is inadequate)
1.5.2 Data Acquisition Board
A data acquisition board must be installed in the host computer. Typical Amplicon boards
designed to address the EX206 are:
1.
Amplicon PC226 Data Acquisition Board providing •
•
•
•
16 channels full differential analog input
Flexible counter - timer facilities
Internal/external clocks and triggers
24 lines digital input/output
1.5.3 Interconnection Cables
Cables to interconnect the host and the expansion boards are required. See Appendix A.3 for
standard available lengths.
40 way twisted pair ribbon cables for analog signals
14 way ribbon cables for control signals
26 way ribbon cables for digital input/output (EX205 and EX206 Panels only)
5 way power cables (optional)
Note on PC226E a D type to ribbon cable converter EX202 must be used.
Page 4
EX206
1.6
Technical Outline of EX206 Panel
The EX206 Transducer Excitation, Signal Conditioning and Termination Panel is designed to
operate in conjunction with a PC226 data acquisition board and provides termination and
conditioning facilities for 16 true differential analog input channels. Termination is also provided
for the analog output channels, control signals and 24 lines of digital input/output. A cold
junction reference channel and an accurate voltage reference channel with selectable levels
maintain accuracy and an analog trigger facility allows data acquisition to commence on an
analog event. For ease of connection, all terminals for external connection are of the lever
operated cage-clamp construction to accept a conductor .
Also available from the Amplicon 200 Series is the EX205 Expansion Panel, and up to seven
EX201 panels can be connected to a single host board to provide a total capacity of 240
analog input channels. None of the 16 original PC226 - EX206 analog input channels is
forfeited when expansion multiplexers are added. Each EX201 can have its discrete address
(level) in the range 1 to 7 selected by an on-board rotary DIL switch. The EX206 Panel is
always allocated address level 0. See the Amplicon Liveline Ltd catalogue for additional
termination panels or assemblies.
The EX206 is located external to the host PC and can be clipped onto DIN rails, placed on a
bench or mounted on a flat panel. For optimum space utilisation, the expansion panels can be
mounted in a multi-layer stack. Optional cables allow the first panel to be up to 2.0 metres from
the PC connectors and subsequent EX201 modules to be up to 0.5 metres apart. (See section
2.3.3.1 for further cable length information).
The sixteen individual channels of the EX206 are each provided with a voltage or current
source to excite external transducers. Each of the sixteen sources may be individually set for
one of four current levels or one of five voltage levels according to the requirements of the
transducer. On board components may be introduced into the circuit to complete quarter and
half bridges
Each analog input channel of the EX206 is also equipped with an option socket to allow signal
conditioning by hardware, channel by channel, to individual needs. A selection of plug-in
modules is available for specific applications such as thermocouple measurements, current
inputs or protection against the application of excessive input voltage. The use of blank
headers will allow a combination of non-standard configurations, including input filters,
attenuators, even active circuitry, to be easily implemented by the user. With no components in
the option socket, the EX206 will operate normally without signal conditioning.
A feature of the EX206 is its ability to acquire low level signals from strain gauges, RTDs,
thermocouples and other sensors. For this purpose, the host data acquisition board will be set
to the appropriate high gain on any input channel allocated to a thermocouple, and the EX206
is designed to keep added noise and offset to a minimum. All input terminals (which provide
the 'cold junction') are on an isothermal copper ground plane and the temperature of this plane
is measured by a temperature sensor with the value continuously available for sampling on a
dedicated channel. The cold junction compensation, thermocouple linearisation, tare offset or
other conditioning is carried out in the host computer using standard polynomials for the
common thermocouple types.
A further feature of the EX206 is an on board voltage reference, user selectable to a value of
0, ±5.0 mV, ±50 mV, ±500 mV or ±5 V by a jumper pad. In a multiple EX201/6 system, each
expansion board can have a different value selected. The reference values can be sampled at
any time on dedicated channels and will be used for diagnostic monitoring and drift correction
when the highest performance level is required.
An additional function provided by the EX206 allows data acquisition to be triggered when an
incoming analog signal passes through a pre-set value (set-point). This set-point value is in the
range ±10 V and may be programmed from the host computer or applied from an external
EX206
Page 5
source. The trigger channel may be either the differential analog input channel 0 when a
programmed gain of 1, 10, 100 or 1000 may be applied to the signal, or a dedicated, singleended channel with a single input voltage range of ±10 V.
Power for the EX206 is normally derived from the +5 V rail of the host PC. The ±15 V rails
required internally are generated by an on board dual DC to DC converter with all voltage
supply rails decoupled and filtered, but in some high noise environments, or where there is
insufficient power available from the host PC, any or all voltage rails can be fed from external
clean supplies.
The EX206 is designed for use inside an enclosed and shielded cabinet when installed within a
normal industrial environment. To ease installation, the full range of features including true
differential operation, rugged construction, ease of signal wiring and industry standard
mounting facilities will be of benefit.
1.6.1 EX206 Block Diagram
A simplified block schematic of the EX206 is shown in Figure 1. The EX206 is compatible with
all user I/O of a multi-function host board, terminating and conditioning the analog and digital
input and output signals available on the PC226
Analog Input
Of the sixteen analog input channels (numbered 0 to 15), 1 through 15 are connected directly
(via optional signal conditioners) to the corresponding channel inputs of the host data
acquisition board, PC226. Channel 0 signals are switched by the sub-multiplexer and channel
0 is routed for data acquisition when expansion level 0 is addressed. In operation the host
PC226 transmits an address via the control cable, and if the relevant bits of this address
coincide with address level 0, then the EX206 analog input channels are activated. The
remaining bits of the address word designate the appropriate path through the sub multiplexer
to select either the cold junction reference signal at address 16 (10 16) or the voltage reference
at address 24 (1816). For any addresses other than level 0 or the two reference channels, the
sub-multiplexer is disabled and signals from the EX201 expansion system occupy channel 0.
The selection process and circuitry are designed to maintain the data acquisition speed of the
system.
Transducer Excitation
Many types of transducer need to be powered, and this excitation must be accurate, stable and
in many cases, independent of other channels. Different types of transducer necessitate a
current or voltage drive, and the power requirements vary according to the characteristics of
the transducer. Each channel of the EX206 is equipped with an independent transducer
excitation source with jumper settings to allow current or voltage drive selectable by jumpers.
Each channel may be set individually to 0.5, 1.0, 2.5 or 5.0 mA current excitation or 1.0, 2.0,
5.0, 10.0 or 15 V voltage excitation.
Bridge Completion Components
Each channel of the EX206 will accept signals from bridge circuits such as strain gauges
where the sensor is in a quarter, half or full bridge configuration. Quarter or half bridge circuits
normally need to have resistors added to the circuit to complete the full bridge, and the EX206
has component positions in header sockets to add these precision resistors. The values
required will depend on the bridge characteristics and it is the user's responsibility to select and
fit the correct components.
Page 6
EX206
Cold Junction Reference
All analog input signal clamp terminals are mounted on a copper isothermal plane. The
temperature of this copper plane is monitored by an accurate solid state sensor mounted at the
centre point of the plane. The input terminals form the 'cold junction' when thermocouples are
connected as signal inputs, and the 'cold junction' temperature may be read at any time by
addressing a dedicated analog input channel (Channel 16 for the EX206). Knowledge of the
instantaneous 'cold junction' temperature allows all thermocouple readings to be accurately
compensated for changes of environment.
Voltage reference Generator
An independent, accurate voltage reference generator on the EX206 may be set to a suitable
value and monitored by addressing a dedicated channel (Channel 24 for the EX206).
Monitoring this channel during a data acquisition run gives confidence that the system is
operating properly and allows correction of inaccuracies during post processing should this be
necessary.
Analog Trigger
Circuits on the EX206 provide a set-point and comparator facility to allow PC226 data
acquisition to be triggered when an analog input signal passes through a programmed level.
Both the trigger set-point level and the analog signal have jumper selectable sources which
may be operated in the following combinations:
TRIGGER SET-POINT
ANALOG INPUT SIGNAL
Programmable DAC providing
64 discrete voltage levels in
the range ±10 V
Channel 0 differential analog input signal.
Programmable gain setting of 1, 10, 100
or 1000 applied after conditioning.
External analog set-point
voltage in the range ±10 V on
dedicated input terminal
External, single-ended analog input signal
voltage in the range ±10 V on dedicated
input terminal
Analog Output
A low resolution analog output is available on the EX206 from the set-point DAC, and this
output provides ±10 V referenced to analog ground. This output may be programmed from the
PC226.
Control Signals
The three control signals, Counter 2 Output, Clock/Gate and External Trigger are terminated
on the EX206. The external trigger signal to the PC226 can be directly from an external digital
source or derived from the analog level trigger circuits in the EX206.
Digital Input/Output
The 24 lines of Digital I/O are directly terminated by the EX206 with a cage-clamp terminal for
each line. 100k pull down resistors ensure that high impedance, open circuit lines to not
appear as 1 levels.
EX206
Page 7
Control Signals
Input/Output
(6 Terminals)
USER
INPUT/
OUTPUT
TERMINALS
Ext. Dig Trigger In
Analog Signal In
Analog Set-Point In
Analog Set-Point Out
Analog
Trigger
Level
Set-Point
Circuits
/
8
Level 0
Selection and
Control Logic
8 Address Signals
from Host Data
Acquisition System
Voltage Reference
Generator
Cold Junction
Reference Source
B
R
I
D
G
E
Excitation and
Differential
Analog Input for
Channels 0 to 15
(16 x 4
Terminals)
Clock/Gate
Cntr 2 O/P
Trigger
Aux2
B
R
I
D
G
E
CONTROL CABLE
SubMultiplexer
CHAN 00
Current/Voltage
Excitation
Signal Conditioning
Header Module
CHAN 01
Current/Voltage
Excitation
16 Chans Analog
Signals to Host
Data Acquisition
System PC226
Signal Conditioning
Header Module
= Differential Pair
B
R
I
D
G
E
CHAN 15
Current/Voltage
Excitation
Signal Conditioning
Header Module
DAC Analog
Output + Return
Terminals for
Channels 0 to 3
(7 Terminals)
4 Chans Analog
Output from Host
Multi-function
Board (when
supported)
SIGNAL CABLE
20 TWISTED PAIRS
24 Line Digital
Input/Output
(2 x 12
Terminals)
/
26
Figure 1
Page 8
Digital Input/Output
DIGITAL I/O CABLE
BLOCK SCHEMATIC OF EX206
EX206
HOST
PC
WITH
PC226
BOARD
1.7
Contacting Amplicon Liveline Limited for Technical Support or Service
The EX206 is manufactured by Amplicon Liveline Ltd. Maintenance is available throughout the
supported life of the product.
1.7.1 Technical Support
Should the EX206 Panel appear defective, please check the information in this and the host
data acquisition board manual and any 'Help' or 'READ.ME' files appropriate to the program in
use to ensure that the product is being correctly applied.
If an application problem persists, please request Technical Support on one of the following
numbers:
Telephone: UK
International
01273 608 331
+44 1273 608 331
Fax:
01273 570 215
+44 1273 570 215
Internet
UK
International
support@amplicon.co.uk
www.amplicon.co.uk
1.7.2 Repairs
If the EX206 Panel requires repair then please return the goods enclosing a repair order
detailing the nature of the fault. If the EX206 is still under warranty, there will be no repair
charge unless any damage is a consequence of improper use. Warranty terms and conditions
are as stipulated in the current Amplicon Liveline catalogue.
For traceability when processing returned goods, a Returned Materials Authorisation (RMA)
procedure is in operation. Before returning the goods, please request an individual RMA
number by contacting Amplicon Customer Services by telephone or fax on the above numbers.
Give the reason for the return and, if the goods are still under warranty, the original invoice
number and date. Repair turnaround time is normally five working days but the Service
Engineers will always try to co-operate if there is a particular problem of time pressure.
Please mark the RMA number on the outside of the packaging to ensure that the package is
accepted by the Goods Inwards Department.
Address repairs to:
Customer Services Department
AMPLICON LIVELINE LIMITED
Centenary Industrial Estate
BRIGHTON
East Sussex
BN2 4AW
England
EX206
Page 9
2
GETTING STARTED
The EX206 contains static sensitive devices. Be aware of the caution
advised in paragraph 1.3 when unpacking the EX206 board.
2.1
Assembling and Mounting the EX206 Panel
The EX206 is supplied with a mounting kit comprising the following items:
6
4
4
2
101.6 mm (4.0") Side Covers
25.4 mm (1.0") Side Covers
Carrier Feet
Lateral Covers
)
)
)
)
8
25 mm Insulated, threaded spacers with mounting screws (3mm)
Carrier Frame
Components
2.1.1 Assembling the Carrier Frame
Identify the carrier frame components. These are orange coloured plastic parts which snap
together in a similar manner to Lego® building blocks. Be aware that firm pressure is required
to snap the sections together and due care should be exercised during this operation.
Assemble the frame as shown in Figure 2 below, leaving the lateral cover at one end open to
slip the EX206 board into its slot.
With the board in position, components up, clip the second lateral cover in position and ensure
that the whole assembly is tightly clipped together. In this condition the board in its frame can
be mounted on a DIN/EN TS 32 or TS 35 mounting rail or safely laid on a bench for test
purposes.
Carrier Feet (4 off)
Lateral Covers (2 off)
101.6 mm (4.0”) Side Covers (6 off)
Figure 2
25.4 mm (1.0”) Side Covers (4
ff)
ASSEMBLY OF THE EX206 CARRIER FRAME
If it is required to mount the board on a panel, the eight insulated, threaded spacers should be
fitted to the EX206 printed circuit board in the eight holes provided. It is not essential that the
Page 10
EX206
carrier frame is fitted when panel mounting, but is advised for the additional protection it
affords.
For use in conjunction with EX201 Expansion Panels, see section 3, 'Making The Connections'
and Section 2.6.1.3, 'Auxiliary Power Supplies - Long Connection Cables' for guidance on
positioning the expansion boards.
2.1.2 Stacking the Panels
Figure 3 illustrates stacking of the expansion panels to occupy minimum space and to use
minimum length of interconnecting cables. The carrier frame is not shown fitted.
Digital I/O
Signal and Control Cables
from Data Acquisition Board
EX206
EX201
EX201
EX201
Figure 3
STACKING EX201/EX206 EXPANSION PANELS
2.1.3 Mounting the Panel on a DIN Carrier Rail
The EX206 when assembled in its frame can be clipped onto a standard DIN/ES carrier rail.
Suitable rails are the TS 32 'G' section rail or TS 35 'top hat' section rail. Figure 4 illustrates the
method of mounting to the two types of rail.
‘G’ Section TS 32 Rail
Figure 4
‘Top Hat’ Section TS 35
MOUNTING THE EX206 ON A DIN RAIL
The frame includes four plastic carrier feet which should all be assembled in the same
direction. Locate the fixed slot of each foot over the appropriate rail edge and carefully press
the whole assembly down onto the rail until all four feet click into position.
EX206
Page 11
To dismount the EX206 in its frame, lift all four 'handles' to release from one rail edge and
unhook from the other edge.
2.1.4 Mounting the Board or Board Stack on a Flat Panel
If a single board or stack of boards is to be mounted on a flat panel, using the insulated
spacers provided, the dimensions of the mounting hole centres are given in Figure 5. Fixing
screws are 3mm Ø.
This mounting pillar (metal) may be
used for connection to chassis ground
365.8 mm (14.4”)
134.6 mm (5.3”)
121.9
mm
(4 8”)
134.6 mm (5.3”)
86.4 mm (3.4”)
88.9 mm
(3.5”)
50.8 mm (0.2”)
16.5 mm (0.65”)
Figure 5
2.2
EX206 BOARD MOUNTING DIMENSIONS
Quick Start
If an independent EX206 Panel is being installed, or an EX206 with the addition of a single
EX201 Expansion Panel, then the factory default settings (see para. 2.13) will normally be
acceptable and a quick start can be made. If multiple boards or optional header modules are
required for the installation, then first set up the boards as described later.
1.
Install the PC226 Data Acquisition Board in the host computer (PC) as described in the
relevant technical manuals. The two connectors will protrude through the chosen I/O slot of the
PC. The digital I/O cable can be connected via an optional EX204 (for PC226) or EX203 (for
PC226E) adapter plate, or dressed through the adjacent I/O slot or any convenient opening in
the PC housing.
2.
If you have a PC226E Data Acquisition Board, connection to the EX206 should be made
via an EX202 adapter, which converts the D-type connectors of the PC226E and EX203 over
to the IDC connectors used by the EX205/6. The EX202 adapter has been designed to be
panel mounted, providing IDC connection to the EX205/6 mounted inside the panel, and
providing D-type connection to the host computer. Connect the EX202 to the PC226E and
EX203 by means of three screened cables. These are standard cables available from
Amplicon and comprise a 44-way for the signal cable, a 15-way for the control/power cable and
a 37-way for the digital I/O (EX203). This arrangement has been designed to meet EMC
requirements.
3.
Mount the EX206 in a suitable position for the cables to reach, and, ensuring that the
PC is turned OFF, connect the EX206 to the data acquisition board, or the EX202 if
appropriate, by means of two equal length (normally 1.0 or 2.0 metres) 14 and 40 way ribbon
cables. The third (26 way) cable for digital Input/Output is longer as it may have to reach the
far end of the PC board. These are standard cables available from Amplicon in various lengths
and comprise a 40 way (20 twisted pairs) for the signal cable, a 14 way flat ribbon for the
Page 12
EX206
control/power cable and a 26 way for digital I/O. The connectors are bump polarised so can
only be inserted when correctly orientated. Ensure that the connectors are pressed firmly
home. Handle the cable assemblies by the connector bodies when inserting or
extracting the connectors.
Personal Computer
PC226
Data Acquisition
Board installed
in Host PC
Analog I/O Signal Cable
40 way (2 x 20 way)
Twisted Pairs Ribbon
Digital I/O Cable
26 way
Flat Ribbon
EX206
Panel
‘Daisy Chain’
connection of
multiple expansion
panels.
System expansion
to maximum of
one EX206 and
seven EX201
EX201 Expansion Panel
Input/Output available
on this final connector
pair in any chain of
expansion
boards.
Pinout as host data
acquisition board.
EX201 Expansion Panel
Figure 6
Control Cable
14 way
Flat Ribbon
SIGNAL AND CONTROL CABLE CONNECTIONS TO PC226
EX206
Page 13
PC226E
Data Acquisition
Board and EX203
adapter installed
in Host PC
Personal Computer
37 way Screened Digital I/O Cable
15 way Screened Control Cable
44 way Screened Analog
I/O Signal Cable
EX202 Adapter
Digital I/O Cable
26 way
Flat Ribbon
Analog I/O Signal Cable
40 way (2 x 20 way)
Twisted Pairs Ribbon
Control Cable
14 way
Flat Ribbon
EX206
Panel
‘Daisy Chain’
connection of
multiple expansion
panels.
System expansion
to maximum of
one EX206 and
seven EX201
EX201 Expansion Panel
Input/Output available
on this final connector
pair in any chain of
expansion
boards.
Pinout as host data
acquisition board.
EX201 Expansion Panel
Figure 7
Page 14
SIGNAL AND CONTROL CABLE CONNECTIONS TO PC226E
EX206
4.
At the EX206, plug the 40 way connector from the PC or EX202 to either PL1 or PL2
and the 14 way connector to either PL3 or PL4. Note that these are parallel pairs of IDC plugs
for 'daisy chaining' several expansion boards together. Except for tidy dressing of the cables, it
is not important which IDC plug is chosen. Digital I/O is not 'daisy chained', and the 26 way
cable should be plugged into PL7 of the EX206.
5.
If an EX201 is also to be connected, a second, short pair of cables is required, and the
two expansion panels are interconnected in the chain as shown by the upper two external
boards in Figure 6. The final pair of connectors on the chain of expansion boards provide I/O
pin-out to exactly the same configuration as the host data acquisition board.
The 'quick-start' system is now ready to use and a voltage reference channel and cold junction
reference signal are available in addition to the sixteen analog input channels. The channel
addresses for a basic system comprising a PC226 or PC226E Data Acquisition Board and an
EX206 Panel are tabulated in Figure 8 below. The full list of 256 channel addresses is given in
appendix B.
• Transducer excitation is factory set at +10.0 V on each channel
• Trigger source is set for Analog Trigger
• Analog trigger is factory set for programmable trigger set-point with the power-up
level reset at –10 V. A new set-point value is loaded by program
• Analog trigger signal input is factory set for channel 0 with power-up gain reset at
1000. A new gain value is loaded by program
Channel Address Selected
by Host Board
Figure 8
FUNCTION
Decimal
Hex
EX206 (Fixed Level 0)
00
01
02
03
04
05
06
07
08
09
10
11
12
13
14
15
16
24
0016
0116
0216
0316
0416
0516
0616
0716
0816
0916
0A16
0B16
0C16
0D16
0E16
0F16
1016
1816
Analog I/P CHAN 00
Analog I/P CHAN 01
Analog I/P CHAN 02
Analog I/P CHAN 03
Analog I/P CHAN 04
Analog I/P CHAN 05
Analog I/P CHAN 06
Analog I/P CHAN 07
Analog I/P CHAN 08
Analog I/P CHAN 09
Analog I/P CHAN 10
Analog I/P CHAN 11
Analog I/P CHAN 12
Analog I/P CHAN 13
Analog I/P CHAN 14
Analog I/P CHAN 15
Cold Junction Ref.0
Voltage Reference 0
CHANNEL ADDRESSES FOR A SINGLE EX206 SYSTEM
EX206
Page 15
2.3
Setting Up the EX206
Setting up the EX206 only needs to be done if the requirements stipulated in the 'Quick Start'
mode (Section 2.2, first paragraph) are exceeded. Setting up requires the common board
features to be set up for the required system attributes and each channel to be configured for
the characteristics of the transducer to be connected to that channel.
Attention must be paid to the following on-board hardware set up features before connecting
the EX206 into circuit. Other variables are controlled from the host computer system and
reference should be made to the data acquisition board or software manual as appropriate.
Feature
Paragraph
On-board Voltage Reference
Auxiliary Power Supplies
Trigger Source
Analog Trigger Set-Point
Analog Trigger Input Channel
Transducer Excitation
Bridge Completion
Input Signal Conditioning
2.4
2.6
2.7
2.8
2.9
2.10
2.11
2.12 and Section 4
Jumper J10 connects GND and AGND together for test purposes only and must not be fitted.
2.4
On-board Voltage Reference
Each expansion panel (EX201 and EX205/6) is equipped with a precise reference voltage
generator that can be configured as required by the user. Each generator can be interrogated
by the host computer program, and its value sampled and recorded in exactly the same way
that the acquired analog values are sampled. It is up to the user's program to interrogate the
reference signals and to interpret the merit of these embedded reference data points. Proper
interpretation will enhance the user's confidence that the acquired data are accurate and valid.
Areas of application include:•
Real time error checking
•
Post processing correction of zero and full scale drift.
•
Diagnostic routines
2.4.1 Selecting the Reference Voltage
The on-board reference voltage can be set by means of the jumper pad J1 - J5 to any one of
the following nine levels:
0V, +5.0 mV, -5.0 mV, +50.0 mV, -50.0 mV, +500 mV, - 500 mV, +5.0 V or -5.0 V
Factory default setting of the EX206 is +5.0 V (Factory default setting of the EX201 Expansion
Panel is +500 mV). To set the reference voltage to a different value, locate the jumper pad J1 J5 on the EX206 and position the two jumpers as indicated in Figure 9 below. The last setting
in this table shows a configuration for applying a zero voltage input signal raised to +5 V
common mode. This setting can be useful for test and diagnostic purposes.
The voltage reference signal is coupled from its source to the host data acquisition board using
a differential wire pair to minimise pick-up and offsets. The dedicated input channel address
number for the voltage reference signal from the EX206 is 24 (1816).
Page 16
EX206
The gain of the voltage reference dedicated input channel must be set to a value
commensurate with the voltage level selected, and the gain setting will normally be the same
as an input channel used for comparison. Details of channel address and channel gain settings
are given in the appropriate PC226 technical reference manual.
Reference
Voltage Level
J1 - J5 JUMPER SETTINGS
Positive Polarity
Negative Polarity
J1 J2 J3 J4 J5
±5.000 V
J1 J2 J3 J4 J5
–
B
–
B
+
A
+
A
J1 J2 J3 J4 J5
±0.500 V
(±500 mV)
J1 J2 J3 J4 J5
–
B
–
B
+
A
+
A
J1 J2 J3 J4 J5
±0.050 V
(±50.0 mV)
J1 J2 J3 J4 J5
–
B
–
B
+
A
+
A
J1 J2 J3 J4 J5
±0.005 V
(±5.00 mV)
J1 J2 J3 J4 J5
–
B
–
B
+
A
+
A
J1 J2 J3 J4 J5
Zero Volts
(Ground)
–
B
+
A
J1 J2 J3 J4 J5
Zero volts input
+5.0 V common
mode
Figure 9
–
B
+
A
JUMPER SETTINGS FOR REFERENCE VOLTAGE SELECTION
EX206
Page 17
2.4.2 Re-calibration of the Reference Voltage
The reference voltage source is factory calibrated at room temperature and is set at 5.000V.
The source voltage can be checked and adjusted if necessary by powering the EX206 and
connecting an digital voltmeter across the test points TP1 (AGND) and TP3. The DVM should
have an accuracy of better than ±0.05%. Set the source to +5.000 V precisely by means of the
multi-turn potentiometer RV1. The lower reference levels are derived from this 5 volt source by
means of precision resistors and will not require individual calibration.
The range of adjustment of the reference source is typically ±1.0 V. If required, the reference
can be set by the user to any value within this range of adjustment. For instance it may be
desirable to set it to 5.12 or 4.096 volts for a direct binary correspondence, or it may be
preferred to set it to 4.90 volts to fit in the 5 volt data acquisition range.
2.5
On-board Cold Junction Temperature Reference
A popular requirement for a multi-channel low level analog input system is to acquire data
from a large number of thermocouples. The flexibility of the EX206 allows any of its input
channels to be used for accurate measurement of thermocouple signals with minimal
deleterious thermal effects or induced offsets.
A thermocouple is two dissimilar thermo-elements connected so that a thermal EMF is
produced when the measuring and reference junctions are at different temperatures. The
measuring junction is located at the external position whose temperature is being monitored
and this measuring junction is connected directly or via compensating extension cables to the
input terminals of the EX206. The points at which the incoming thermocouple wires join these
terminals are effectively the reference or 'cold' junctions.
The actual temperature of these reference junctions will be near the ambient temperature of
the surroundings, whereas thermocouples are normally referred to 0°C. The cold junction
compensation technique used in the EX206 is to measure the temperature of the terminals
and perform a calculation in the host computer to determine the actual temperature at the
measurement head by a linearisation/compensation polynomial equation for the particular
thermocouple type.
The 'cold junction reference temperature' is measured by a semiconductor sensor centrally
mounted on a copper isothermal plane embracing all the low level input terminals. The sensor
circuit produces a stable, accurate and linear output of 10.0 mV/°C over the full working
temperature range of 0° C to +55° C, the output at 0° C being zero mV. This reference signal is
coupled to the host data acquisition board on a dedicated input channel using a differential wire
pair to minimise pick-up and offsets.
The dedicated input channel address number for the cold junction reference signal from the
EX206 is 16 (1016). The gain setting of this input channel is user programmed to a value for
the 'best fit' of the reference signal to the full scale of the host analog input board. A gain
setting of 200 in the unipolar mode will provide a reference temperature range of 0°C to 50°C
ambient, sufficient for most applications. Details of channel address and channel gain settings
are given in the appropriate PC226 technical reference manual.
See the section 4 'Analog Input Signal Conditioning' for a description of thermocouple open
circuit detection, filters and ground reference paths. No hardware configuration of the EX206,
except the possible insertion of a header for open circuit detection, is required for the cold
junction reference.
Page 18
EX206
2.6
Auxiliary Power Supplies
Expansion modules EX201 and EX205/6 are normally powered by the +5 VDC rail of the host
computer via the 14 way ribbon power/control cable, and no provision needs to be made to
power the expansion boards separately. However, in many circumstances, particularly with
powered transducer circuits, it may be necessary for the user to provide separate power
supplies and features are incorporated in the Panels to allow this.
2.6.1 The Need for Auxiliary Power Supplies
An EX206 used without EX201 expanders and without external transducer excitation will not
normally require auxiliary powering.
Because the EX206 is designed to excite external transducers, the power demand
means that it is normally necessary to provide external power for the EX206 ±15 V
supplies.
However, the circumstances under which auxiliary powering of the EX206 should be
considered are:
1.
Power demand by voltage or current excited transducers.
Power for the transducers is derived from the ±15 V rails, and the on board source is a
DC-DC converter with limited capacity. Typically, the EX206 can provide up to a total of
32 mA to the sum of the external loads, and this will represent excitation for one of the
following transducer combinations without resorting to external supplies:
•
•
•
•
Sixteen current driven RTDs at 1 mA current excitation
Two 350Ω bridge circuits excited by 5 V sources
Two LVDTs at 15 mA each
One two wire transducer at 20 mA
If the sum of the currents required by all the excited transducers connected to the
EX206 exceeds 32 mA, then the EX206 must be externally powered on its ±15 V
supplies. The +5 V can remain powered from the PC if all other criteria are met.
To calculate the total external current requirement, consider each channel in turn. For
the current excited transducers, add all the individually set currents for those channels.
For voltage driven devices, calculate the individual currents from the voltage set for that
channel and the resistance of the device. For partial bridges, take account of the bridge
completion resistors fitted on the EX206.
2.
Insufficient power available from the host PC +5 VDC supply.
The EX206 draws a minimum of 240 mA and each EX201 expansion panel typically
draws 150 mA from the +5 V rail. A fully expanded system without external demands
would therefore require about 1.3 A from the host PC. If the user's computer has other
adapter boards installed, and this problem of insufficient power is suspected, then a
power budget must be calculated from the manufacturers’ data pertaining to the various
boards plugged into the PC compared with the manufacturer's specification for available
current on the +5 V rail.
3.
Long connection cables.
When powered from the host PC, the expansion panels derive their +5 V via the control
interconnect cables. The table in Figure 10 shows the maximum lengths of control
interconnecting cable which apply for all combinations of expansion boards (one EX206
and up to seven EX201). A longer first signal cable up to 5 m length can be used where
EX206
Page 19
mounting arrangements demand it, but 2 m maximum is recommended to meet the
specified rise times and the expansion boards will need to be powered separately.
If auxiliary power supplies are connected, the special power interconnect cables used for
these supplies are rated at higher currents, and can be 2.5 times the indicated lengths.
The signal interconnect cables are twisted pairs and can only be manufactured in
multiples of 0.5 m length, so use next appropriate length.
Number of Expansion
Panels EX201/206
Control Cable Length
PC to First EX Panel
Control Cable Length
Between EX Panels
1
2
3
4
5
6
7
8
2m
1m
1m
50 cm
50 cm
30 cm
30 cm
20 cm
N/A
1m
50 cm
50 cm
30 cm
30 cm
25 cm
20 cm
Figure 10
INTERCONNECTION CABLE LENGTHS
For most practical purposes, quantities above three panels or where there are
external excitation demands should be powered from auxiliary supplies.
3.
Best Low Level Performance
Each expansion panel is equipped with a DC to DC converter to supply isolated ±15 V to
the on-board analog circuits. DC to DC converters include an oscillator which is a
potential noise source, and a trace of noise can be induced in the low level analog
circuits. The design of the EX206 ensures that any such induced noise is low, but when
the best possible low level performance is required, facilities have been provided to
disable each DC to DC converter and feed the analog circuits from external, isolated
±15 V linear power supplies.
4.
Power Consuming Custom Option Modules
Customised option modules may be powered from the ±15V analog supplies. The
maximum sum of all currents to be drawn from these internal supplies by all modules
and by any external powered transducers is 32 mA total. If current in excess of 32 mA
is to be drawn, then the EX206 power must be supplied from the auxiliary power inputs.
Provision of external power supplies is the user's responsibility, and the following requirements
must be met for a fully expanded system.
+5 V at 1.3 A
+15 V at 500 mA
–15 V at 300 mA
Suitable power modules from Amplicon Liveline. Check the current catalogue.
Page 20
EX206
2.6.2 Configuration of the EX206 for Auxiliary Power
The EX206 is supplied with the jumpers configured for operation from the computer +5 V
supply rail with the ±15 V derived from the on-board DC to DC converter. Powering the EX206
from auxiliary supplies will require changes to the configuration by repositioning jumpers
according to the table in Figure 11. For information on connecting the auxiliary power supplies
to PL5/6 see section 3, 'Making the Connections'.
Auxiliary Power Supplies - Jumper Configuration
EX201/6 Power Source
+5 V
Jumper J6 to J9
Settings
±15 V
J8
Host PC via
Control Cable
On-board
DC to DC
Converter
J9
J7
On-board
DC to DC
Converter
Auxiliary
±15 V
Power Supply
J9
J7
Host PC via
Control Cable
J9
J7
Figure 11
1
2
3
4
5
)
)
Not Used
)
+5 V Aux. Input
GND (0 V)
1
2
3
4
5
+15 V Aux. Input
- 15 V Aux. Input
AGND (Isolated)
+5 V Aux. Input
GND (0 V)
1
2
3
4
5
+15 V Aux. Input
- 15 V Aux. Input
AGND (Isolated)
Not Used
Not Used
J6
J8
Auxiliary
±15 V
Power Supply
Not Used
J6
J8
Auxiliary
+5 V
Power Supply
)
)
)
)
)
(Factory default setting)
J9
J7
1
2
3
4
5
J6
J8
Auxiliary
+5 V
Power Supply
PL5/6 Auxiliary Power
Connector Usage
J6
AUXILIARY POWER SUPPLY JUMPERS
EX206
Page 21
2.7
Jumper Setting for Analog or Digital Trigger Source
The 'External Trigger' signal, required by the PC226 to initiate data acquisition in the 'External
Trigger' mode of operation, is available through the EX206, and can be derived from one of
two sources, selectable by jumper J12
From Set-Point Source J11
From Analog Trigger Source J13
+
–
Set-Point
Comparator
Digital Trigger I/P
CON7 3
Figure 12
To PC226
Ext Trigger
DIG
ANA
J12
ANALOG/DIGITAL TRIGGER SOURCE JUMPER J12
Analog Trigger Source
With the jumper J12 in position ANA (factory default position), a trigger signal is sent to the
data acquisition board when a selected analog signal passes a pre-set level. Selection of
the analog signal source and set-point source are discussed below.
Digital Trigger Source
When jumper J12 is in position DIG, a trigger signal applied to terminal CON7 3 is routed
directly to the 'External Trigger' input of the PC226. The externally applied signal must be
referred to digital ground (CON7 1) and the characteristics of this signal must meet the
requirements of the host board, these being:
Input Voltage
'0' or Low
'1' or High
0 to 0.5 V
+2.1 min to +28 V max
Input Impedance
> +5 Volt Input
< +5 Volt Input
1 kΩ nominal
15 kΩ nominal
Trigger action can take place on the rising or falling edge of the trigger signal as selected by
the program.
2.8
Selecting the Trigger Set-Point Source
In the 'Analog Trigger' mode of operation, the EX206 employs on-board circuits to generate a
trigger signal when the value of an analog input passes a pre-determined set point. The value
of this set-point is in the range ±10 V and is from one of two sources, selectable by jumper
J11.
Page 22
EX206
6 Data Bits from PC226
D to A
Converter
LOAD DAC (Aux2) from PC226
To Set-Point
Comparator +
SET
DAC
J11
Set-Point Voltage
I/P via CON7 8
Figure 13
SET-POINT SOURCE JUMPER J11
Programmable DAC Set-Point Source
With the jumper J11 in position DAC (factory default position), the set-point value is derived
from the output of a Digital to Analog Converter whose digital input value is set by the
program. Operation of this set-point D/A Converter is discussed in Section 5.
Analog Voltage Set-Point Source
When the jumper J11 is placed in position SET, the set-point value is derived from an
external source supplied by the user. This set-point voltage is applied to CON7 8 and is
referred to Analog Ground on CON7 9. The set-point voltage must be in the range ±10 V
and the input impedance is 47.5kΩ.
2.9
Selecting the Analog Trigger Signal Source
In the 'Analog Trigger' mode of operation, the EX206 employs on-board circuits to generate a
trigger signal when the value of an analog input passes a pre-determined set point. The analog
signal used for launching the trigger is derived from one of two channels, selectable by jumper
J13.
EX206 Channel 0 I/P
CON1 2 and CON1 3
Signal
Conditioning
To Data Acquisition
Programmable Gain
1, 10, 100 or 1000
Dedicated I/P Channel
CON7 6
Figure 14
J13
CH0
To Set-Point
Comparator –
DED
ANALOG TRIGGER SIGNAL SOURCE JUMPER J13
Channel 0 Trigger Signal Source
With the jumper J13 in position CH0 (factory default position), the trigger is derived from the
analog signal on input channel 0 of the EX206. System wiring must be arranged such that
the signal source for triggering data acquisition is connected to channel 0. The signal on
this channel may also be logged in the normal way and the signal characteristics must
comply with the specifications for analog inputs. The trigger signal source is picked off after
EX206
Page 23
conditioning, so any attenuation, filtering or other header module operations will apply to
both the trigger signal and the logged signal.
A programmable gain, differential amplifier is incorporated in this channel 0 analog trigger
circuit, and the gain is programmed from the PC226 data acquisition board. This amplifier
allows a wide range of analog signals to be used for trigger, and gains will be set according
to the following table:
Channel 0 I/P Voltage Range
Gain Setting
Control Bits
–10 mV to +10 mV
–100 mV to +100 mV
–1.0 V to +1.0 V
–10.0 V to +10.0 V
1000
100
10
1
11
10
01
00
Dedicated Channel Trigger Signal Source
When the jumper J13 is placed in position DED, see fig 14 jumper connecting centre pin to
DED, the trigger is derived from a user furnished analog signal on a dedicated input line
CON7 6. This signal is single-ended, referred to Analog Ground (CON7 9 'ATRG') and must
be in the range –10.0 V to +10.0 V. Input impedance is 47.5 kΩ.
2.10
Setting the Transducer Excitation Parameters
External transducers that demand excitation from the EX206 must have the appropriate
parameters set up on a channel by channel basis so that the excitation conforms with the
characteristics and requirements of the particular transducer. The EX206 can supply one of
five voltage or four current excitation for each channel, with the appropriate selection being
made by jumper settings. Two groups of jumpers are provided for each channel. One group
sets that channel for voltage or current excitation, and the other group sets the excitation level.
Refer to Section 4 for a further discussion on transducer excitation and signal conditioning
2.10.1Voltage or Current Selection
Selection of voltage or current excitation for each channel is by the orientation of a pair of
jumpers on a 4 way header group. Positioning the pair horizontally selects voltage excitation
for that channel (Default setting) and positioning them vertically selects current excitation for
that channel.
An illustration of the jumper positions and a jumper reference table for each channel are shown
in Figure 15 below.
Page 24
EX206
VOLTAGE/CURRENT SELECTION JUMPER REFERENCES FOR EACH CHANNEL
Channel
Number
Jumper
Number
Channel
Number
Jumper
Number
Channel
Number
Jumper
Number
Channel
Number
Jumper
Number
00
J 001
04
J 041
08
J 081
12
J 121
01
J 011
05
J 051
09
J 091
13
J 131
02
J 021
06
J 061
10
J 101
14
J 141
03
J 031
07
J 071
11
J 111
15
J 151
Figure 15
SELECTION OF VOLTAGE OR CURRENT EXCITATION
2.10.2Selecting the Value of the Voltage or Current Excitation
Selecting the required excitation value of voltage or current for each channel is by the position
of a jumper in a 5 in-line header group. Only one jumper must be inserted in a group and the
selected voltage or current for that position and channel references are shown in the tables
below. The excitation output is always positive polarity with reference to analog ground.
Jumpers viewed from component side with Serial Number to the left.
Jumper JXX2 Position
Excitation Voltage
Excitation Current
J XX2
+1.0 V
+0.5 mA
J XX2
+2.0 V
+1.0 mA
J XX2
+5.0 V
+2.5 mA
J XX2
+10.0 V
+5.0 mA
J XX2
+15 V
Not Applicable
EXCITATION VOLTAGE/CURRENT JUMPERS FOR EACH CHANNEL
Channel
Number
Jumper
Number
Channel
Number
Jumper
Number
Channel
Number
Jumper
Number
Channel
Number
Jumper
Number
00
J 002
04
J 042
08
J 082
12
J 122
01
J 012
05
J 052
09
J 092
13
J 132
02
J 022
06
J 062
10
J 102
14
J 142
03
J 032
07
J 072
11
J 112
15
J 152
Figure 16
2.11
MAGNITUDE OF EXCITATION VOLTAGE OR EXCITATION CURRENT
Mounting the Bridge Completion Modules
Strain gauges and other transducers are often connected in bridge circuits, and the active
element(s) can comprise a quarter (one element), half (two elements) or full (four elements)
configurations. For measurement purposes, the bridge must be completed to form a full four
EX206
Page 25
arm circuit, and it is necessary to add passive precision resistors to each channel for this
purpose.
See section 4 for a discussion of the various bridge configurations, identification of completion
components and external wiring. This section should be read before installation of the EX206
if bridge completion components are required for the application.
NOTE:
The Bridge Completion Modules require that +EXC and -LO signal tracks are
open circuit at the appropriate point. Provision is made for this by means of drill points by the
side of each module socket. Once a track has been opened, that channel will not operate
without a header module in position, but the open circuit track can be easily restored for
normal operation if later required. DO NOT OPEN THE DRILL POINTS OF ANY EQUIPMENT
ON EVALUATION.
2.12
Mounting the Analog Input Signal Conditioning Modules
The analog input signal on each channel of the EX206 may be 'conditioned' before it reaches
the active multiplexer circuitry. Signal conditioning ensures that the incoming signal is made
compatible with the characteristics of the data acquisition system, and is performed on the
EX206 by individual channel plug-in modules which can be standard items or custom
designed.
Section 4 of this manual includes a description of these optional signal conditioning modules,
and should be read before installation of the EX206 if signal conditioning is required for the
application.
NOTE:
Modules that include series components in the differential analog input lines
require that the tracks are open circuit at the appropriate point. Provision is made for this by
means of drill points under each module socket. Once a track has been opened, that channel
will not operate without a header module in position, but the open circuit track can be easily
restored for normal operation if later required.
DO NOT OPEN THE DRILL POINTS OF ANY EQUIPMENT ON EVALUATION.
Page 26
EX206
2.13
Summary of Factory Settings for Jumpers and Pluggable Components
Default settings of the positions on the EX206 are tabulated below.
Jumper
Factory Setting
Function
J1
J2
J3
J4
J5
J6
J7
J8
J9
J10
J11
J12
J13
Position A
Not fitted
Not fitted
Not fitted
Position B
Fitted
Upper position
Upper position
Upper position
Not fitted
Left position (DAC)
Left position (ANA)
Upper position (CH0)
+5 V reference
±500 mV reference
±50 mV reference
±5 mV reference
Reference ground
DC to DC converter input
+5 V from PC
+15 V from DC to DC converter
–15 V from DC to DC converter
Test purposes only. Do not fit
Analog Trigger set-point source
Analog/Digital trigger
Analog Trigger signal source
J001 - J151
J002 - J152
Horizontal Pair (V)
Vertical Position 2
Excitation Voltage/Current select
+10 V Excitation
SK0 - SK15
DP0A/B - DP15A/B
No module fitted
Unopened
Signal conditioning module positions
Signal conditioning module drill points
RB001 - RB141
No module fitted
Bridge completion module positions
DP0C - DP15C
DP0D - DP15D
Unopened
Unopened
Bridge component C drill points
Bridge component D drill points
EX206
Page 27
3
MAKING THE CONNECTIONS
The EX206 Transducer Excitation, Signal Conditioning and Termination Panel can form part of
a multi-channel system and a number of connections must be made for the system to function
properly. Connections from panel to panel and to the host board are made by multi-way
interconnect cables and user connections are by single wires to individual terminals.
3.1
Positioning the Expansion Panels
Before making any connections each board should be assembled in its frame and firmly
mounted in position. If several expansion panels (EX205/6, EX201 and compatible future
panels) are to be integrated in a single system, then the spacing should be such that they can
be interconnected by the chosen cables, normally 0.5 m (18 - 20") length, allowing some
leeway so that the cables can be handled without stress. The cables to connect with the host
computer are available in recommended nominal lengths of 0.5, 1.0 and 2.0 m, but lengths up
to 5 m can be used with a proportionate increase in analog signal rise times.
If the panels are to be stacked, the frames are not required. Start with the lowest board, set the
switch (EX201 only) and jumpers to the correct positions and ensure that any component
headers for signal conditioning or bridge completion are fitted. The interconnect ribbon cables
may now be plugged into the first board. Build up the stack, ensuring that each board is
properly configured and the ribbon cables connected as each board is added.
All incoming signal wires are marshalled at the external panel terminals and space must be
available to properly dress and connect these individual wires. It is the responsibility of the
installer to ensure good screening and mounting positions are complied with to maintain EMC
compliance.
3.2
Panel Interconnect Cables
The EX206 panel and the EX201 panels are interconnected by two, three or four sets of
prepared ribbon cables. These sets are referred as the 'Control Interconnect Cables', the
'Signal Interconnect Cables', the 'Digital I/O Cable' and the optional 'Auxiliary Power
Interconnect Cables'. Connections to the host computer are made with similar cables either
directly to PC226 or via the EX202 adapter to a PC226E.
Board interconnection is by 'daisy chain' (except Digital I/O) and all daisy chained cables and
connectors employ a straight through, parallel path so they are not position sensitive.
The range of standard cables with part numbers is given in appendix A.3.
3.2.1 Control Interconnect Cables
The control interconnect cables are 14 way flat ribbon cables with 26 AWG flexible conductors.
The cables are fitted with a 14 way bump polarised IDC connector at each end, symmetrically
wired pin 1 to pin 1 etc.
Control connector pin-outs are shown in Figure 17. The expansion boards use the address
lines pins 1 through 8, the +5 V line on pin 13 and ground pin 14. The Auxiliary 2 line is used
on the EX206 for loading set-point data to the trigger DAC and the Trigger I/P line connects the
trigger signal from the EX206 to the host data acquisition board. The remaining control and
power lines on pins 9, 12, 13 and 14 are terminated for user connection on the EX206.
Page 28
EX206
1 2
Address 1 >
Address 4
Address 16
Address 64
CNTR 2 O/P
Trigger
+5 V PC Power
Address 2
Address 8
Address 32
Address 128
Auxiliary 2
Clock/Gate
Digital GND
14 WAY RIBBON CABLE
CONTROL AND POWER
INTERCONNECTIONS
13 14
Figure 17 CONTROL CONNECTOR PIN-OUTS
3.2.2 Signal Interconnect Cables
The signal interconnect cables are 40 way (20 twisted pairs) flat ribbon cables with 28 AWG
flexible conductors. The cables are fitted with a 40 way bump polarised IDC connector at each
end, symmetrically wired pin 1 to pin 1 etc. The pin-outs are shown in Figure 18. All analog
input and output signal lines plus the ground returns are available for user connection on the
EX206.
1 2
+ Analog I/P 00
+ Analog I/P 01
+ Analog I/P 02
+ Analog I/P 03
+ Analog I/P 04
+ Analog I/P 05
+ Analog I/P 06
+ Analog I/P 07
+ Analog I/P 08
+ Analog I/P 09
+ Analog I/P 10
+ Analog I/P 11
+ Analog I/P 12
+ Analog I/P 13
+ Analog I/P 14
+ Analog I/P 15
Analog O/P DAC0
Analog O/P DAC1
Analog O/P DAC2
Analog O/P DAC3
– Analog I/P 00
– Analog I/P 01
– Analog I/P 02
– Analog I/P 03
– Analog I/P 04
– Analog I/P 05
– Analog I/P 06
– Analog I/P 07
– Analog I/P 08
– Analog I/P 09
– Analog I/P 10
– Analog I/P 11
– Analog I/P 12
– Analog I/P 13
– Analog I/P 14
– Analog I/P 15
Gnd Rtn DAC 0
Gnd Rtn DAC 1
Gnd Rtn DAC 2/3
AGND (Analog Ground)
>
40 WAY (20 Twisted Pairs)
RIBBON CABLE FOR ANALOG
SIGNAL INTERCONNECTIONS
39 40
Figure 18
SIGNAL CONNECTOR PIN-OUTS
3.2.3 Digital Input/Output Cable
The digital I/O cable is a 26 way flat ribbon cable with 28 AWG flexible conductors. The cable
is fitted with a 26 way bump polarised IDC connector at each end, wired pin 1 to pin 1 etc.
Figure 19 shows the pin-outs. The EX206 terminates all the digital I/O lines for user
connection.
EX206
Page 29
1 2
Port A0
Port A2
Port A4
Port A6
Port B0
Port B2
Port B4
Port B6
Port C0
Port C2
Port C4
Port C6
+5 V PC Power
Port A1
Port A3
Port A5
Port A7
Port B1
Port B3
Port B5
Port B7
Port C1
Port C3
Port C5
Port C7
Dig. GND
>
26 WAY RIBBON CABLE
FOR DIGITAL INPUT/OUTPUT
CONNECTIONS
25 26
Figure 19
DIGITAL I/O CONNECTOR PIN-OUTS
3.2.4 Auxiliary Power Cables
The optional auxiliary cables are 5 way flat ribbon cables with 22 AWG flexible conductors for
higher current carrying capacity. The board interconnection cables are fitted with a 5 way
polarised socket at each end, symmetrically wired pin 1 to pin 1 etc. The expansion board to
power supply cable has pig-tails at one end for connection to the chosen power sources.
The pin-outs are shown in Figure 20. The expansion boards use the +5 V with GND return
and/or the ±15 V with dedicated AGND (analog ground) return as required. See section 2.6 for
the use of auxiliary power supplies. These separate grounds must NOT be connected
together.
1
2
3
4
5
+15 V Aux. Power I/P
– 15 V Aux. Power I/P
AGND (Analog ground)
+5 V Aux. Power I/P
GND (Power ground)
Figure 20
5 WAY RIBBON CABLE
FOR AUXILIARY POWER
INTERCONNECTIONS
AUXILIARY POWER CONNECTOR PIN-OUTS
3.2.5 User Manufacture of Interconnect Cables
The above paragraphs provide enough information for user manufacture of cables if special
lengths are required. Refer to section 2.6.1 and Figure 10 for maximum cable lengths if power
is drawn from the host computer.
3.2.6 Screened Cables and Chassis Ground Connections
In a hostile noise environment, or to maintain EMC compliance of PC226E, an advantage may
be gained by using overall screened twisted pair cable for the signal interconnects. Such
cables may be user manufactured or check the Amplicon catalogue for availability of standard
items. If overall screened cables are used, the drain wire should be connected to the most
convenient of the GND terminals on the EX206, CON5 or CON6.
Page 30
EX206
Facilities are provided to connect the screens of any shielded interconnect cable to benign
chassis ground (earth) of the users equipment in which the EX206 is installed.
3.3
Analog Signal Input Connections
Proper connection of the analog input signals is the essence of good data acquisition. Noise,
offsets, static and magnetic fields, ground currents, thermal and chemically generated EMFs,
poor electrical connections are all enemies of low level signal measurement and the
appropriate method of handling must be utilised to combat detrimental effects from such
interference.
The design of the 200 Series has set out to reduce such effects to a minimum and to provide
the tools for connecting signals from a variety of sources. Features of the system designed to
help in this respect include:-
•
True Differential Operation
Differential operation allows the measurement of a signal at its source without interference
from voltages existing between the grounds of the sending and receiving devices. The
balanced operation of the differential circuit means that interfering signals induced in the signal
wiring cancel out leaving the desired signal clean.
•
Separate High Quality Analog Ground
The analog ground circuit is kept completely separate from the power/digital ground and these
grounds are only connected together at one point close to the Analog to Digital Converter on
the data acquisition board. Using this technique no significant currents flow in the analog
ground circuits. It is important that this ground separation is maintained through the system.
•
High Common Mode Input Impedance
Minimal common mode ground return currents flow through the signal lines.
•
Thermal Balance
Any dissimilar metal contact causes a small thermal EMF to be generated (Seebeck effect). All
connections in the analog input circuits are therefore balanced and kept at a uniform
temperature by an isothermal plane. Any thermal EMFs are equal and opposite so have
minimum effect on the measured value.
•
Cage-Clamp Input Terminals
Commonly used screw-down terminals can become loose or can be over-tightened and
damage the signal wires so causing problems through poor connections. The cage-clamp
terminal system used on the EX201, EX205 and EX206 applies a constant force to the wire
being clamped so ensuring a consistent and stable low resistance connection.
•
Optional Individual Channel Filters
If noise is a problem and the noise is at a high frequency compared to the signal being
measured, then any channel can have a filter installed to reduce the interfering signal.
All such measures rely on the source analog signal being properly connected into the system,
and the following notes provide examples to assist with the design and layout of the input
wiring. The principles of input signal connections apply whether the signal source is unpowered
such as a thermocouple, or is a transducer such as a strain gauge that receives its excitation
EX206
Page 31
from the EX206. The actual wiring configurations of various types of transducer are shown in
section 4.
3.3.1 The Terminal Connectors
All input terminals to the EX206 are of the lever operated, cage-clamp type, allowing quick,
easy and reliable connection of any incoming wire size. If more than one wire is to be held in a
single terminal, prepare these wires by stripping and twisting together before clamping.
Each terminal on the EX206 is provided with a built-in push lever to operate the cage-clamp.
The lever may be depressed using a small screwdriver or other convenient tool, and when the
clamp is opened, the wire to be connected is pushed home in the slot and the operating lever
released.
Small Screwdriver
Prepared
Signal Wire
Figure 21
OPERATING THE CAGE–CLAMP TERMINAL
3.3.2 Typical Input Channel Connections
Each of the sixteen analog input channels on an EX206 is equipped with a four terminal
connector group. Figure 22 illustrates a typical group.
The three terminals are labelled 'EXC', '+HI, '–LO' and 'AGND' and the functions are:
EXC
+HI
-LO
AGND
Page 32
is the excitation output for voltage or current powered transducers
is the positive or high input.
is the negative or low input.
is the analog ground connection. This high quality ground line is kept
separate from the digital and power ground lines.
EX206
The typical channel connections shown in Figure 22 are repeated sixteen times on the EX206
and these sixteen channels are labelled CHN 0 through CHN 15. Figure 23 shows the location
of the input terminals on the board and the appropriate group can be located on terminal
blocks CON1 through CON4, grouped as follows:
Channel 0 to 3
CON1
Channel 4 to 7
CON2
Channel 8 to 11
CON3
Channel 12 to 15 CON4
Excitation
Signal High
Signal Low
Analog Ground
AGND
-LO
Figure 22
+HI
EXC
CONNECTIONS TO A TYPICAL CHANNEL
3.3.3 IMPORTANT NOTES - Please read before making connections
1.
Do not connect any grounded (earthed) point of the signal source to the AGND terminal
of the expansion board. If common mode voltages exist, heavy ground currents would flow
through this connection and could offset the desired low level signal. See the examples given
in 3.3.4 on connection to the AGND terminal.
2.
Measure the common mode voltage. e.g. the potential difference between the ground
point of the signal source and the ground of the host PC. This common mode voltage could be
AC or DC or a combination.
3.
Using an isolated voltmeter, connect one probe to the ground of the signal source and
the other to the ground of the PC. Any length of probe extension lead can be used for this
measurement. Try both AC and DC ranges of the voltmeter and note any readings. Any
electrical equipment in the area should be switched on.
4.
If the peak potential difference is greater than 10 volts, then do not connect this signal
source to the EX206. A high common mode voltage probably indicates a fault in the electrical
system, but if conditions are correct, a special configuration will be required to measure signals
in the presence of a high common mode voltage. See Section 4, 'Analog Input Signal
Conditioning'. Without protection, common mode voltages in excess of 15 volts can
permanently damage the equipment.
EX206
Page 33
ANALOG INPUT CHANNELS
CHN 0
CHN 7
CHN 8
CHN 15
A
E
- G
X H L N
C I O D
A
E
- G
X H L N
C I O D
A
E
- G
X H L N
C I O D
A
E
- G
X H L N
C I O D
CHANS
01 - 06
CON1
CHANS
09 - 14
CON2
CON3
CON4
CON8
CON7
A0 A1 A2 A3 A4 A5 A6 A7 C4 C5 C6 C7 B0 B1 B2 B3 B4 B5 B6 B7 C0 C1 C2 C3
DIGITAL I/O PORTS (GROUPS A and B)
+5 V
CLK
DTRG
DGND
CTR2
O/P
CONTROL
I/O
Figure 23
Page 34
ASET
ATRG
0RTN
AGND
ALEV
ANALOG
TRIGGER
SIGNALS
0O/P
2O/P
1O/P
1RTN
ANALOG
O/Ps
LAYOUT OF USER SIGNAL INPUT/OUTPUT CONNECTIONS
EX206
3O/P
2/3RTN
3.4
Signal Sources and Their Methods of Connection
Signal Sources can generally be defined as one of the following types:
Differential - Fully floating
Differential - With ground reference
Single-ended
Multiple single-ended with common ground.
The examples given below are not exhaustive but show various ways of connecting these
types of source. Note that the AGND terminal is only used for connecting to a passive shield
and the excitation return current. In no case does the AGND carry a signal or its return.
A typical data acquisition system will be connected to a variety of source types, and the
connection methods can be mixed as required across the channels.
3.4.1 Unused Inputs
Unless all sixteen channels are connected to signal sources, some input terminals will be
floating. It is advisable to link the three terminals (+HI, –LO and AGND) together on unused
input channels. Alternatively, a wired header can be inserted in the appropriate channel's
signal conditioning module option socket. See Figure 24 and section 4.
22 21 20 19 18 17 16 15 14 13 12
O
– LO
AGND
Figure 24
+ HI
EXC
1 2 3 4 5 6 7 8 9 10 11
LAYOUT OF USER SIGNAL INPUT/OUTPUT CONNECTIONS
3.4.2 Fully Floating Differential Source
If the signal source does not have an electrical path to ground it is fully floating. Typical fully
floating sources are ungrounded thermocouples, batteries or some battery powered
instruments, isolated 4 - 20 mA transmitters.
Methods of connecting to fully floating sources are shown in Figure 25. Parallel pairs of
connecting wires are shown but it is normally preferable to use twisted pairs so that induced
noise is better cancelled.
A fully floating source has no ground reference so it can acquire a static charge that will result
in a high common mode voltage on the input. This can be eliminated by connecting a ground
reference resistor between the 'signal low' line and AGND. The resistor value is not critical and
will normally be 100 kΩ to 1 MΩ. Although shown connected externally, a better method is to
mount the resistor on an optional signal conditioning module header, it can then be combined
with a filter, protection circuit etc. Signal conditioning modules are discussed in Section 4.
EX206
Page 35
A
G
E
N L H X
D O I C
Fully floating source.
Unshielded wire pair
for connection.
Floating
Signal
Source
High
Ground
Reference
Resistor
Low
A
E
G
N L H X
D O I C
Fully floating source.
Shielded wire pair
for connection.
Floating
Signal
Source
High
Ground
Reference
Resistor
Low
A
E
G
N L H X
D O I C
Shielded but
ungrounded fully
floating source.
Shielded wire pair
for connection.
Floating
Signal
Source
Figure 25
High
Ground
Reference
Resistor
Low
CONNECTIONS TO FULLY FLOATING SOURCES
3.4.3 Differential Signal Source
Typical differential signal sources that are referred to their own ground are 'bottomed' or
grounded thermocouples, strain gauge or other bridges, current transmitters, laboratory
instruments. A differential source is not necessarily balanced about ground. Check its DC
offset and ensure that neither the high nor low signal line will exceed ±10 V referred to AGND.
See Figure 26
Measure these voltages and ensure
that 10 V peak is not exceeded
Differential source.
Shielded or
unshielded wire pair
for connection.
V
Differential
Signal
Source
Do not connect to
ground at source
Figure 26
Page 36
CONNECTIONS TO DIFFERENTIAL SIGNAL SOURCES
EX206
E
A
X
H
L
G
N O I C
D
3.4.4
Single-ended Signal Source
Many signal sources provide single-ended output with ground return. Such an output is often
via a co-axial connector when a screened cable is used. The AGND terminal is not used, do
not link it to either +HI or –LO input. Ensure that any peak common mode plus signal voltage
between the source ground and the EX206 AGND does not exceed ±10.0 V.
See the connection details in Figure 27.
A
G
E
N L H X
D O I C
Single-ended source.
Unshielded wire pair
for connection.
Single-ended
Signal
Source
High
A
G
E
N L H X
D O I C
Ground
Single-ended source.
Single shielded
connection cable.
Single-ended
Signal
Source
High
Ground
Figure 27
CONNECTIONS TO A SINGLE-ENDED SIGNAL SOURCE
3.4.5 Multiple Single-ended Signal Source
A single piece of equipment under test may well produce several signals, all referred to its
common ground. Connect the analog inputs as shown in Figure 28, ensuring again that AGND
is not connected.
A
E
G
N L H X
D O I C
Multiple
Single-ended
Multiple single-ended Signal Source
source. Multi-core
shielded cable
for connections.
A
E
G
N L H X
D O I C
A
E
G
N L H X
D O I C
High 3
High 2
High 1
Ground
Figure 28
CONNECTIONS TO A MULTIPLE SINGLE-ENDED SOURCE
EX206
Page 37
3.5
Control Input/Output Connections
The following control and power lines to/from the PC226 are directly terminated on CON7 of
the EX206.
PC226 Function
EX206 Label
EX206 Connector
Digital Ground
+5 V Output
Counter 2 Output
Clock/Gate Input
DGND
+5 V
CTR2 O/P
CLK
CON7 1
CON7 2
CON7 4
CON7 5
The +5 V output terminal (CON7 2) voltage is derived from the host PC or the auxiliary supply
as set up on the EX206.
Refer to the PC226 Technical Manual for an description of the control functions.
3.6
Trigger Input/Output Connections
The external signals required for analog or digital trigger functions are terminated on CON7 of
the EX206.
EX206 Function
EX206 Label
EX206 Connector
Digital Trigger Input
Dedicated Analog Trigger I/P
Analog Set-Point Input
Analog Ground
Analog Level o/p
DTRG
ATRG
ASET
AGND
ALEV
CON7 3 (Refer to DGND on CON7 1)
CON7 6 (Refer to AGND on CON7 9)
CON7 8 (Refer to AGND on CON7 9)
CON7 9
CON7 7
Page 38
EX206
3.7
Digital Input/Output Connections
The 24 lines of digital I/O are terminated on the EX206 on terminal block CON8. Each line is
pulled down to digital ground by a 100 kΩ resistor. The terminal sequence is arranged as two
groups (Group A and Group B) as defined for the 82C55 Programmable Peripheral Interface
device used on the PC226.
Group Port (Label)
A
A
A
A
A
A
A
A
A
A
A
A
B
B
B
B
B
B
B
B
B
B
B
B
PC226/EX204 Pin
EX206 Pin
EX203 Pin
A0
A1
A2
A3
A4
A5
A6
A7
C4
C5
C6
C7
B0
B1
B2
B3
B4
B5
B6
B7
C0
C1
C2
C3
PL3 - 1
PL3 - 2
PL3 - 3
PL3 - 4
PL3 - 5
PL3 - 6
PL3 - 7
PL3 - 8
PL3 - 21
PL3 - 22
PL3 - 23
PL3 - 24
PL3 - 9
PL3 - 10
PL3 - 11
PL3 - 12
PL3 - 13
PL3 - 14
PL3 - 15
PL3 - 16
PL3 - 17
PL3 - 18
PL3 - 19
PL3 - 20
CON8 1
CON8 2
CON8 3
CON8 4
CON8 5
CON8 6
CON8 7
CON8 8
CON8 9
CON8 10
CON8 11
CON8 12
CON8 13
CON8 14
CON8 15
CON8 16
CON8 17
CON8 18
CON8 19
CON8 20
CON8 21
CON8 22
CON8 23
CON8 24
1
20
2
21
3
22
4
23
5
24
6
25
7
26
8
27
9
28
10
29
11
30
12
31
+5 V O/P
DIG GND
PL3 - 25
PL3 - 26
CON10 2
CON10 1
13
32
The +5 V and digital ground lines available on CON7 apply to digital I/O and control I/O. The
layout of the digital input/output terminations on the EX206 panel is shown in Figure 23
EX206
Page 39
4
ANALOG SENSOR AND INPUT SIGNAL CONDITIONING
There are three distinct operations to be performed on the hardware configuration of each
channel to prepare it for proper operation with the chosen transducer or other signal source.
• Transducer Connection Configuration with appropriate Bridge Completion
• Transducer Excitation
• Conditioning of Analog Input Signal
The setting up of the board together with details of placement of jumpers and other
components is covered in Chapter 2, 'Getting Started'. This chapter covers the choice of the
proper components and selection of the best values for operation under a variety of different
conditions.
4.1
Transducer Connection Configuration
The EX206 will supply power to, and accept signals from a variety of transducers, sensors and
other signal sources. To correctly configure the wiring for a particular type, attention must be
paid to the connections between the transducer and the four terminals per channel on the
EX206, any links between these terminals, header modules for any links or components in the
bridge completion area and, if required, header modules for signal conditioning.
4.1.1 Excitation Configuration
The user must determine the type and amount of excitation required, and set the jumpers
accordingly. Take due account of the following factors when deriving the best setting for the
voltage or current excitation.
•
•
•
•
•
•
Transducer manufacturer's published data
The effect and current drain of the bridge completion components that may be required
Dissipation and self-heating effect in sensor elements
The measurement range and resultant level of the output signal
The common-mode voltage
The maximum and minimum values given in the tables below
Voltage Excitation
Voltage
Typical
Accuracy
Max
Current
Min Sensor
Resistance
Typical Applications
+1.0 V
±1.0%
16 mA
62 Ω
Low Power Bridge
+2.0 V
±1.0%
16 mA
125 Ω
Low Power Bridge
+5.0 V
±1.0%
16 mA
312 Ω
Solid-state Sensor, Bridge Excitation
+10.0 V
±1.0%
30 mA
333 Ω
LVDT, Bridge Excitation
+15.0V
±20%
30 mA
500 Ω
Two wire transducers
Page 40
EX206
Current Excitation
Current
Typical
Accuracy
Compliance
Max Sensor
Resistance
Max Sensor
Dissipation
Typical Applications
+0.5 mA
±5.0%
10.0 V
20000 Ω
5 mW
Thermistor
+1.0 mA
±5.0%
8.0 V
8000 Ω
8 mW
Thermistor
+2.5 mA
±5.0%
5.0 V
2000 Ω
12.5 mW
Thin Film RTD
+5.0 mA
±5.0%
2.0 V
400 Ω
10 mW
PT-100
For absolute accuracy of measurements made using sensor excitation, a scaling factor can be
used for each channel, and incorporated into the software control. Connect a stable, known
input signal source to a channel on the EX206, take a measurement on that channel, and note
the reading. The scale factor can be calculated as follows:
scale factor = source value / reading
4.1.2 Bridge Completion Header Modules
The EX206 is supplied with 22 way DIL sockets to allow for standard header modules to be fitted,
providing bridge completion facilities on each channel. These modules fitted with appropriate
resistors allow the use of quarter, half or full bridge sensors with two, three or four wire connection.
The resistors are supplied by the user and mount onto standard Custom Configuration Headers
(Amplicon part number 919 254 70) which insert into sockets on the EX206.
As supplied the EX206 is fitted with links across components A and C, and component B open-circuit
(see Figure 29). This configuration will cater for the majority of transducers, but when quarter or half
bridges are to be used, components A, B and C can be used instead to complete the bridge circuit
(see Figure 29 below).
DPxC
A
Vs
+ EXC
A
B
B
+ HI
C
Signal
– LO
C
AGND
DPxD
Figure 29
BRIDGE COMPLETION COMPONENTS
Fitting the Bridge Completion Modules
The bridge completion resistors are mounted on a 22 pin component header (Amplicon part
number 919 254 70) which plugs directly into its appropriate socket. There are eight bridge
completion sockets on the EX206, each one supporting two channels. The socket for
EX206
Page 41
channels 0 and 1 is RB001, channels 2 and 3 is RB021, channels 4 and 5 is RB041, and so
on.
1. Locate the correct socket.
2. Four drill points can be seen directly adjacent to the socket, two for each channel.
These drill points link across component A and across component C, and are marked
DP0C (component A) and DP0D (component C) for channel 0; DP1C (component A) and
DP1D (component D) for channel 1, and so on. These drill points complete the circuit by a
plated through hole, so by drilling through the hole with a 1mm drill, the series circuit is
broken. NOTE: Drill points that have been opened can be easily closed by linking through
the hole and soldering either side.
After drilling out both drill points associated with the channel of interest, insert the
module by properly aligning the pins and pressing it home.
BE AWARE OF THE CORRECT ORIENTATION (See Figure 30) :*
Pin 1 of the header is indicated by a chamfer at one corner.
* The pin 1 end of the board mounted socket is indicated by an indent at the outer edge of
the socket.
Channel x
Channel x + 1
Socket on EX206
A
B
C
A
B
C
22 21 20 19 18 17 16 15 14 13 12
22 21 20 19 18 17 16 15 14 13 12
RBx1
1 2 3 4 5 6 7 8 9 10 11
1 2 3 4 5 6 7 8 9 10 11
Champfer
Indent
DPxC
Figure 30
DPxD DPx+1C
DPx+1D
BRIDGE COMPLETION MODULE ORIENTATION
Configuring the Sensor
The following diagrams are examples of how to configure quarter, half and full bridge
sensors using the EX206 Bridge Completion modules. For information on selecting the
appropriate resistor refer to the sensor manufacturer's data.
A
Vs
+ EXC
Signal
– LO
AGND
Page 42
B
+ HI
3 wire RTD in voltage
driven quarter bridge
EX206
C
A
Vs
+ EXC
B
+ HI
2 wire RTD or strain
gauge in voltage
driven quarter bridge
Signal
– LO
AGND
C
A
Vs
+ EXC
B
+ HI
Strain gauge in voltage
driven half bridge
Signal
– LO
AGND
C
A
Vs
+ EXC
B
+ HI
Strain gauge in voltage
driven full bridge
Signal
– LO
C
AGND
Figure 31
SENSOR CONFIGURATIONS
4.1.3 Signal Conditioning Header Modules
As supplied, the EX206 Termination Panel accepts analog voltage signals within a ±10 V range. With
the channel by channel programmable gain and polarity options available on the host data acquisition
board, this input signal range will satisfy many requirements without the need for special signal
conditioning.
However various types of signal source do require some form of conditioning to produce a
compatible voltage signal and the EX206 provides means to equip each channel with a pluggable
module designed for the specific requirement.
A range of standard signal conditioning modules are available from Amplicon and these are
described in section 4.2. Blank headers are also available for the user to construct modules as
required for specific applications. Design notes and typical examples are given later in this section.
4.2
Standard Signal Conditioning Modules
Three standard types of input signal conditioning modules are available and these can be fitted to any
channel and mixed with unconditioned channels or custom modules as required. The three standard
modules are:
The Thermocouple Input Module
The 4 to 20 mA Current Input Module
The Multiplexer Protection Module
See para. 4.2.2
See para. 4.2.3
See para. 4.2.4
Part numbers of these modules and the blank header are given in appendix A.3.
EX206
Page 43
4.2.1 Fitting the Signal Conditioning Modules
The module is mounted on a 22 pin component header and plugs directly into its appropriate socket.
The socket for channel 0 is SK0, channel 1 is SK1 etc.
1.
Locate the correct socket.
2.
For the standard modules described below, and for custom modules that are fitted with
series resistors, the board must be prepared by breaking the input lines to the
multiplexer.
Through the openings in each socket, two drill points can be seen, these are marked
DP0A, DP0B for channel 0 + and -, DP1A, DP1B for channel 1 + and - etc. These drill
points complete the circuit by a plated through hole, so by drilling through the hole with a
1mm drill*, the series circuit is broken. NOTE: Drill points that have been opened can be
easily closed by linking through the hole and soldering either side.
After drilling out both drill points associated with the channel of interest, insert the
module by properly aligning the pins and pressing it home.
BE AWARE OF THE CORRECT ORIENTATION (See Figure 32) :*
Pin 1 of the header is indicated by a chamfer at one corner.
*
The pin 1 end of the board mounted socket is indicated by an indent at the outer
edge of the socket.
Signal Conditioning
Header Module
(Shown fully loaded)
Sockets for Header
Modules
SK 0 to SK15
22 21 20 19 18 17 16 15 14 13 12
22 21 20 19 18 17 16 15 14 13 12
DPxA
1 2 3 4 5 6 7 8 9 10 11
Champfer
Figure 32
DPxB
1 2 3 4 5 6 7 8 9 10 11
Indent
SIGNAL CONDITIONING MODULE ORIENTATION
* NOTE
Due to manufacturing tolerances of the PCB and hole sizes, it may be advantageous to break the
tracks by using a larger drill (2.5mm dia) as a countersink tool, just to remove the top of the pad,
however care must be taken not to drill through the PCB, as re-instatement of the circuit will be
impossible. After drilling, a continuity check on the underside of the board should be performed.
Page 44
EX206
4.2.2 Thermocouple Input Module.
The thermocouple input module circuit diagram is shown in Figure 33.
-15 V
10 MΩ
Analog Input
Signal Terminals
10 kΩ
10 MΩ
AGND
1 MΩ
1 µF
To
Multiplexer
Input
10 kΩ
AGND
Figure 33
THERMOCOUPLE SIGNAL CONDITIONING MODULE
This module performs three functions, ground reference, open circuit thermocouple detection and
signal filtering. Both drill points for the appropriate channel must be opened when this module is
fitted (see 4.2.1/2 above).
1.
Ground Reference.
The 1 MΩ resistor provides a path to ground for fully floating thermocouples. The
resistor will have no degrading effect on grounded or 'bottomed' thermocouples.
2.
Open Circuit Detection
The 10 MΩ resistors have minimal effect on the thermocouple reading in normal use.
However, should the thermocouple burn out or otherwise go open circuit, then the input
voltage rises to cause the analog to digital converter to go over full scale in a negative
direction and so set the overrange flag to indicate an open circuit fault.
3.
Filter
The two 10 kΩ resistors and 1µF capacitor form a balanced low pass filter with a cut off
frequency of about 8 Hz. This filter provides good attenuation of 50/60 Hz pickup and
higher frequency noise.
4.2.3 4 - 20 mA Current Input Module.
The 4 - 20 mA input module performs three functions and its circuit diagram is shown in Figure 34.
Both drill points for the appropriate channel must be opened when this module is fitted (see 4.2.1/2
above).
EX206
Page 45
Analog Input
Signal Terminals
10 kΩ
25 Ω
AGND
1 µF
To
Multiplexer
Input
10 kΩ
1 MΩ
AGND
Figure 34
1.
4 - 20 mA CURRENT SIGNAL CONDITIONING MODULE
Ground Reference.
The 1 MΩ resistor provides a path to ground for signals from isolated current
transmitters. The resistor will have no degrading effect on ground referenced sources.
2.
Current Sensor
The current to be monitored flows through the 25 Ω precision resistor, so converting the
signal to a voltage in the range 100 mV to 500 mV which can be directly applied to any
EX206 input channel. The data acquisition board is set to +500 mV full scale for the
monitored channel. Different current ranges can be accommodated by changing the
current sensing resistor to a different value and/or changing the gain setting.
3.
Filter
The two 10 kΩ resistors and 1µF capacitor form a balanced low pass filter with a cut off
frequency of about 8 Hz. This filter provides good attenuation of 50/60 Hz pickup and
higher frequency noise.
4.2.4
Multiplexer Protection Module.
The multiplexer protection module circuit diagram is shown in Figure 35. The purpose of this module
is to protect the circuit from damage by the application of excessive input voltage to the multiplexers.
If the signal voltage is from a low impedance source and it is thought that the input voltage on either
the '+HI' or '–LO' input may exceed ±15 V when the power to the expansion board is on, or exceed ±2
V when the power is off, then the protection circuit should be fitted. Both drill points for the
appropriate channel must be opened when this module is fitted (see 4.2.1/1 above).
Analog Input
Signal Terminals
1 kΩ
+15
AGND
Figure 35
Page 46
-15 V
1 kΩ
MULTIPLEXER PROTECTION MODULE
EX206
To
Multiplexer
Input
4.3
Customised Signal Conditioning Modules
For specialised applications the user can construct input signal conditioning modules designed for a
particular purpose. Blank headers (Amplicon part number 919 254 70) are available for this purpose,
and the design can be passive or use active circuits powered by the ±15 V isolated rails.
The component headers are 0.4" (10.16mm) pitch and the basic layout will allow many designs to be
built by laying components across the header. In other cases it will be necessary to lay components
longitudinally.
Figure 36 shows the general schematic of the input module circuit and the header layout with all
component positions filled. Only a selection of these components will be needed for most
applications.
Circuit elements and their intended functions are as followsResistor R1 is a current sensing resistor for monitoring current rather than voltage
signals. The value of 25 Ω shown is specified for normal process signals of 4 - 20 mA.
Any suitable value for the current to be measured (maximum 1.0 A) can be installed
here. This resistor position can also be used for an element of an attenuator or
protection circuit.
Resistor R2 in conjunction with R1 and R3 provides an 'open circuit detection' facility for
thermocouples.
Resistor R3 is a ground reference resistor to be fitted when the input source is fully
floating.
Resistors R4 and R5 are a balanced pair of precision resistors which form part of filter,
attenuator and protection circuits. When R4 and R5 are installed in any header module,
the associated drill points must be drilled out to open the series circuits.
Resistor Rx when fitted provides an attenuator comprising R4, R5 and Rx. Such an
attenuator is required when the normal mode signal is likely to exceed ±10 V.
Capacitor Cx operating with R4 and R5 provides a simple single pole low pass balanced
filter.
Diodes D1 to D4 require R4 and R5 to be installed. When these components are in
circuit, the voltage applied to the multiplexer cannot exceed ±15.7 V, so protecting the
circuit from overvoltage.
EX206
Page 47
-15 V
-15 V
8
21
D1
R2
10 MΩ
+15 V
9
D2
15
2
14
DPxA
Analog Input
Signal Terminals
4
1
Cx
1 µF
R5
22
17
16
R4
R1
25 Ω
AGND
a
19
To
Multiplexer
Input
Rx
7
18
6
5
b
DPxB
20
13
R3
1 MΩ
D3
12
D4
3
10
AGND
-15 V
11
+15 V
R R R R R R C D D D D
1 2 3 4 5 x x 1 2 3 4
22 21 20 19 18 17 16 15 14 13 12
1 2 3 4 5 6 7 8 9 10 11
Figure 36
4.3.1
GENERAL SCHEMATIC AND LAYOUT OF HEADER MODULE
Typical Examples of Customised Signal Conditioning Modules.
The following circuits provide examples of custom modules that the user may construct for a specific
application.
4.3.1.1 Differential Voltage Input with Ground Reference Resistor
Figure 37 below shows a simple circuit and header layout for fitting a ground reference resistor to any
channel that has a fully floating input source. The drill points must not be opened for this application.
Page 48
EX206
DPxA
a
Analog Input
Signal Terminals
To
Multiplexer
Input
22 21 20 19 18 17 16 15 14 13 12
b
20
AGND
R
3
DPxB
R3
1M
3
1 2 3 4 5 6 7 8 9 10 11
AGND
Figure 37
4.3.1.2
GROUND REFERENCE RESISTOR
Differential Voltage Input with Balanced Low Pass Filter
If noise or an interfering signal is present, and this noise is of a higher frequency than any component
of the required signal then the simple balanced low pass filter can be useful in reducing the unwanted
frequencies.
Refer to the circuit shown in Figure 38. For a cut-off frequency of f Hz, the value of Cx is:Cx = (8 / f) µF
DPxA (Opened)
Analog Input
Signal Terminals
4
R4
10 k
a
19
16
Cx
AGND
18
R5
10 k
5
To
Multiplexer
Input
R
5
C
x
1 2 3 4 5 6 7 8 9 10 11
DPxB (Opened)
Figure 38
4.3.1.3
R
4
7
b
AGND
22 21 20 19 18 17 16 15 14 13 12
BALANCED LOW PASS FILTER
Differential Voltage Input with Normal (Series) Mode Attenuation
Figure 39 shows the circuit and header layout for fitting a normal mode attenuator to any channel. R4
and R5 must be precision resistors of equal value and Rx for the required attenuation factor (A) is
Rx = 2 * R4 / ( A – 1 )
EX206
Page 49
DPxA (Opened)
Analog Input
Signal Terminals
4
R4
10 k
a
19
To
Multiplexer
Input
Rx
AGND
18
R5
10 k
5
R4
R5
R
x
6
b
AGND
22 21 20 19 18 17 16 15 14 13 12
17
1 2 3 4 5 6 7 8 9 10 11
DPxB (Opened)
Figure 39
NORMAL MODE ATTENUATOR
Maximum input signal that may be applied is limited to 200 V peak. Be aware that this circuit does not
attenuate any offset voltage and the peak voltage applied to the multiplexer input must not exceed
±10 V with reference to AGND. See Figure 40 below for a circuit that attenuates both common and
normal mode inputs.
The drill points must be opened for this application. If the source is fully floating, the ground reference
resistor R3 may be added.
Because of the potential risk of applying excess voltage to the multiplexers, it is advised that the
diode protection circuit is added as shown in Figure 40 below.
-15 V
+15 V
8
D1
9
D2
15
14
DPxA (Opened)
Analog Input
Signal Terminals
a
4
19
To
Multiplexer
Input
Rx
R5
AGND
18
6
5
b
DPxB (Opened)
13
AGND
D3
D4
-15 V
Page 50
1 2 3 4 5 6 7 8 9 10 11
12
10
Figure 40
D D D D
1 2 3 4
22 21 20 19 18 17 16 15 14 13 12
17
R4
R R R
4 5 x
11
+15 V
NORMAL MODE ATTENUATOR WITH PROTECTION
EX206
4.3.1.4
Differential Voltage or Current Input with Common Mode Attenuation
DPxA (Opened)
Analog Input
Signal Terminals
4
a
19
R4
To
Multiplexer
Input
R5
AGND
18
22 21 20 19 18 17 16 15 14 13 12
16
5
Rx2
Rx1
7
1 2 3 4 5 6 7 8 9 10 11
b
DPxB (Opened)
Rx2
R4
Rx1
R5
AGND
Figure 41
COMMON MODE ATTENUATOR - VOLTAGE INPUT
To measure signals in the presence of high common mode voltages, balanced attenuators to ground
are required. The attenuator network will reduce the required normal mode signal as well, so
additional gain may be necessary on the channel to compensate.
DPxA (Opened)
Analog Input
Signal Terminals
4
1
19
a
16
R4
To
Multiplexer
Input
R1
R5
AGND
18
22
5
22 21 20 19 18 17 16 15 14 13 12
Rx2
R1
Rx1
7
b
1 2 3 4 5 6 7 8 9 10 11
DPxB (Opened)
Rx2
Rx1
R4
AGND
Figure 42
R5
COMMON MODE ATTENUATOR - CURRENT INPUT
To measure current in the presence of a high common mode voltage, resistor R1 is added to the
attenuator network.
Example:-
To measure up to 20mA in a circuit 24 volts above ground.
If R1 is 25 Ω, maximum measuring voltage across R1 is 20 x 25/1000 = 0.5 V.
Attenuate by a factor of 2.5 so that common mode voltage to multiplexer does not
exceed 10 V. (24 ÷ 2.5 = 9.6 V)
Therefore if R4 and R5 are 10 kΩ each:Rx1 = Rx2 = 2.5 kΩ precision resistors
Maximum signal after attenuation is 0.2 V, so set gain for this channel at 40 unipolar to
give a full scale input range of +0.25 V.
EX206
Page 51
5
PROGRAMMING THE ANALOG TRIGGER
To program the analog level at which the trigger occurs, the software communicates with the EX206
via the eight address lines and the auxiliary control line (AUX2) from the PC226. The AUX2 line was
previously unused, but was provided in the original design specification for applications of this nature.
The trigger signal is returned to the PC226 via the normal trigger signal line.
As well as being accessible on the control I/O connector on the PC226, these nine address and
control signals are all defined in the ADC Control Word Input Register and hence the channel list, and
are therefore readily available to the programmer. AUX2 is normally low, but when set high, it
indicates that the bits on the address lines represent trigger level rather than multiplexor address.
When a trigger level instruction is executed, one of the 256 available addresses will be selected and
a conversion completed. However the resulting value can be ignored.
Although the trigger point can be dynamically set by entering a value in the channel list (with AUX2 bit
set), the normal method will be to set up the trigger value before a data acquisition run commences.
A single value with AUX2 set high and PC226 gain set to bipolar 1 (to minimise the chance of PC226
amplifier saturation), is written to the ADC control word input register, and the gain and set point of
the analog trigger control are automatically entered and latched. The data FIFO can then be cleared
to get rid of any conversion value that has been returned.
The external trigger positive edge and/or external trigger negative edge are set in the PC226 ADC
Start and Stop Source Register. Positive edge occurs as the analog value on channel 0 rises above
the set point, and negative edge occurs as the analog value falls below the set point. Hysteresis is
built into the comparator to reduce jitter.
An additional function to set the trigger point is provided for the PC226, together with the appropriate
additions to DART200 and all the following software supporting the PC226.
Borland C/C++ Library
Microsoft C/C++ Library
Turbo Pascal Library
Windows DLL
DART226
Signal Centre
An additional example program is provided with each language demonstrating Single Channel Mode
sampling triggered by the +EXT analog trigger.
The additional software is not part of the EX206 specification as it will be supplied as an updated
version of the PC226 distribution diskettes (Amplicon Part Numbers 8956166 and 8956167) and a full
description of the PC226 software is given in the PC226 manual.
5.1
PC226 Tools Software
The EX206 Analog Trigger function is supported by the following PC226 Tools:DOS
Borland C++ library and examples
Microsoft C/C++ library and examples
Borland Turbo Pascal library and examples
Windows
Windows DLL and Visual Basic examples
These libraries include a function to set the EX206 analog trigger level. An example program
for each supported language is also provided to demonstrate the analog trigger feature.
Page 52
EX206
5.1.1
Library Function
The following function is provided in the libraries listed above to set the EX206 analog trigger
level. This function should be called before programming the PC226, as it performs a global
reset on the PC226 board.
Set up Analog Trigger Level - setAnaTrigLvl
Function Name :
setAnaTrigLvl
Description :
Programs the EX206 analog trigger level. This function should only
be called when an EX206 is fitted (N.B. the analog trigger is selected
by jumper)
Syntax
C/C++ :
Basic :
Pascal :
Arguments
:
f = setAnaTrigLvl( ipRange, level );
f = setAnaTrigLvl( ipRange, level )
f := setAnaTrigLvl( ipRange, level );
ipRange (integer) - analog trigger input range:
0 = +/-10V (Gain = 1)
1 = +/-1V (Gain = 10)
2 = +/-100mV (Gain = 100)
3 = +/-10mV (Gain = 1000).
Any other values will give the default +/-10V
range.
level (float) - desired trigger level (mV). If this level is
outside the range specified by ipRange, the value will be
clipped to the max/min for that range.
5.1.2
Return Value
:
The function returns the Actual trigger level selected
i.e. the nearest attainable value. This is the actual level
programmed into the EX206.
Prior Calls
:
none
See also
:
none
Example Programs
:
X013
Example Programs
The example program (X013) demonstrates the use of the EX206’s positive-edge analog
trigger to start a sampling process.
In this example the PC226 is programmed for
• Single channel mode
• Channel 0, 10 V, bipolar
• High block speed (400 kHz)
• Start on EX206 +’ve analog trigger at +5 V
• Stop after 100 samples
The 100 samples will be displayed on the screen.
The Visual Basic for Windows example program, ExampleC, has the additional feature of a
scroll-bar to control the trigger level voltage.
EX206
Page 53
5.2
DART200 for the PC226
The DART200 demonstration program fully supports the EX206 analog trigger feature. From
the ‘Setup’ menu, the ‘Trigger Sources...’ dialogue box allows selection of the Analog Trigger.
Note that the same selection is made for EXT Trigger, and jumper J12 on the EX206 must
be correctly set for the trigger you wish to use (see section 2.7 ‘Jumper Setting for Analog or
Digital Trigger Source’ for more details).
Also from the ‘Setup’ menu, the ‘Analog Trigger...’ dialogue box allows you to enter the
desired EX206 analog trigger level, and select the analog trigger input range (±10V, ±1V,
±100mV, or ±10mV).
The DART200 on-line help includes information on the EX206’s analog trigger. Press F1 to
get context-sensitive help from anywhere in the DART200 program.
Page 54
EX206
6
USER’S NOTES
EX206
Page 55
APPENDICES
APPENDIX A
-
TECHNICAL SPECIFICATIONS
Except where otherwise stated, all figures quoted in the specifications are typical at 25°C.
A.1
Hardware Specification
FUNCTION
Externally mounted input/output termination, excitation and
reference module for use with PC226 and future compatible
boards. Operates in conjunction with EX201 Multiplexer
Expansion Panel
ANALOG INPUT
Number of Input Channels
16 user input channels providing true differential operation
corresponding to the 16 channels of the host PC226
1 thermocouple cold junction reference channel
1 precision voltage reference channel
Number of expansion boards
One EX206 with each PC226 plus up to seven EX201
multiplexer expansions to give a total of 240 differential analog
input channels, plus eight each cold junction and voltage
reference channels
Analog Input Ranges
The analog input voltage range per channel is defined by the
gain setting of the host PC226. To vary the analog input range,
voltage attenuators or current sensors can be fitted to individual
channels using option headers
Maximum input hold-off voltage with suitable attenuator, ±200 V
peak
Input Impedance
(Unit powered, on or off channel, no signal conditioning)
Differential (Line to line) or Common mode (Line to ground)
>100 MΩ / <300 pF expanded channels
The above are based on cable lengths of 2.0 metre from host
board to first expansion module and 0.5 metre between
expansion modules
(If unit is not powered and multiplexer input protection is fitted,
the input impedance is 1.0 kΩ, each line to ground)
Multiplexer Protection
A balanced resistive circuit protects channel 0 multiplexer for
input signals up to 10 Vpk over supply rail voltage
Rise Time
No input conditioning, full cable lengths:
EX206
Page i
Channel 0
Channels 1-15
6 µs to 99.9% FSD
3 µs to 99.9% FSD
Input protection headers fitted:
Common Mode Performance
All channels 10 µs to 99.9% FSD
Maximum common mode voltage ±10 V peak
By employing a special configuration of the input option module,
common mode voltages up to ±200 V peak can be
accommodated, with normal mode signal attenuation
Signal Conditioning
Each analog input channel equipped with optional input signal
conditioning facilities.
Analog Signal Conditioning Headers
The
EX206
is
supplied with 22 way DIL sockets to allow standard header
modules to be inserted or the following options to be
incorporated in any valid combination with the necessary
components customer fitted on a header for each channel. Each
channel can have a different combination of signal conditioning
features. No header needs to be fitted for the EX206 to operate
to its standard specification. The headers operate in conjunction
with sensor excitation and are identical to those of the EX201
and EX205
25 Ω Precision resistor for 4 to 20 mA current measurements
Thermocouple open circuit detect
Floating input ground reference resistor
Balanced input filter
Balanced attenuator
Dual polarity multiplexer input protection
Custom passive or active circuit
Sensor ExcitationThe EX206 is equipped with voltage and
current sources for excitation of external sensors as selected for
individual channels. Voltage, current or no excitation can be
configured in any combination across the sixteen channels
Voltage Excitation
Each channel provides
selectable excitation voltages as in table below
Voltage
+15.0V
+10.0 V
+5.0 V
+2.0 V
+1.0 V
Page ii
Typical
Accuracy
±5/–20%
±1.0%
±1.0%
±1.0%
±1.0%
Max.
Current
30 mA
30 mA
16 mA
16 mA
16 mA
Min Sensor
Resistance
500 Ω
333 Ω
312 Ω
125 Ω
62 Ω
EX206
jumper
Typical Applications
Two wire transducers
LVDT, Bridge Excitation
Solid-state Sensor, Bridge Excitation
Low Power Bridge
Low Power Bridge
Current Excitation
Each channel provides
selectable excitation currents as in table below
jumper
Compliance
Max. Sensor
Resistance
Max. Sensor
Dissipation
Typical Applications
+5.0 mA
Typical
Accuracy
±0.5%
2.0 V
400 Ω
10 mW
PT-100
+2.5 mA
±5.0%
5.0 V
2000 Ω
12.5 mW
Thin Film RTD
+1.0 mA
±5.0%
8.0 V
8000 Ω
8 mW
Thermistor
+0.5 mA
±5.0%
10.0 V
20000 Ω
5 mW
Thermistor
Current
Bridge Completion
Each channel is provided with facilities
for bridge completion by user supplied resistors.
Bridge Configurations
Quarter bridge requires 3 user fitted resistors
Half bridge requires 1 link and 2 user fitted resistors
Full bridge requires 2 links
Component Mounting
The EX206 is supplied with 22 way DIL sockets to allow
for bridge completion resistors to be customer fitted using
standard blank header modules.
Other Configurations
Drill-points across component mounting terminals allow
configuration of voltage or current excited sensors or
direct signal connections for un-powered sensors.
Reference Signals
The EX206 is equipped with on board temperature and voltage
reference sources.
Cold Junction Reference. (Dedicated channel 16 (1016))
Temperature Range
Scale Factor
0 to 55°C
10 mV / °C
Measurement Accuracy ± 1°C
Differential temperature, cold junction to measurement
point (Still air)
± 1°C
Voltage Reference. (Dedicated channel 24 (1816))
In a multiple EX201/6 system, each expansion board can
be set to a different reference level. Reference source 5.0
V
Output reference voltage set by jumpers:
EX206
Page iii
0 V, 5 mV, 50 mV, 500 mV or 5.0 V
Positive or negative polarity
Factory Setting
+5.0 V
Relative Accuracy
±0.2%
Stability
±0.025%
(±1% on 5 mV range)
Temperature coefficient 0.01% / °C
ANALOG TRIGGER
A trigger signal for the PC226 is generated when the
conditioned analog signal on channel 0 or dedicated analog
trigger level input passes through a programmed or user
furnished analog set point. The set-point values are tabulated in
Appendix C. Options selected by jumpers
DAC Accuracy
Less than ½ LSB
Triggering Window
± 20mV
ANALOG OUTPUT
Trigger Set-Point Output
The analog value of the trigger set-point is available as an
analog output signal in the range ±10 V with actual values as
tabulated and shaded in Appendix B.
Number of Output Channels
The single set-point output channel plus termination for four
analog output channels corresponding to the four DAC outputs
of a future multi-function board. Individual ground returns for
DAC channels 0 and 1, combined ground return for DAC
channels 2 and 3
Analog Output Ranges
As multi-function host board with no further output signal
conditioning, terminated with 100kΩ pull-down resistors.
DIGITAL INPUT/OUTPUT
Number of Digital I/O Lines
24 digital I/O lines in three ports of eight bits each arranged as
two 12 bit groups A and B. Ports A0 - A7, B0 - B7 and C0 - C7
correspond to the I/O line designations of the Programmable
Peripheral Interface on the host PC226
Clocks/Triggers
Counter 2 O/P
Clock/Gate I/P
Trigger I/P
+5 VDC
Digital Input/Output Conditions
)
)
)
)
To/from host PC board with no
further signal conditioning
Digital I/O lines individually pulled down by 100k resistors.
Signal levels as host PC board
CONNECTORS
Panel Interconnects
Page iv
The EX206 termination panel 'daisy chains' with EX201
expansion panels to host PC226 via:
EX206
Two parallel 40 way IDC for analog I/O
Two parallel 14 way IDC for channel address, control signals
and power
Two earthed cage-clamp terminals for drain wire termination if
shielded ribbon cable is used
Optional external power via two parallel 5 way polarised
connectors
Digital I/O requires a single 26 way IDC cable between the
PC226 and EX206. The EX204 provides rear panel termination.
Connections to a host PC226E board require an EX202 panel,
an EX203, a 44 way 'D' screened cable, and a 15 way 'D'
screened cable.
Terminal Connectors
Analog Input
16 groups of four cage-clamp terminals, one group for each
channel. Each group comprises input positive, input
negative, excitation positive and excitation negative (analog
ground)
Analog Output
9 cage clamp terminals. Five DAC outputs and four
associated ground returns
Trigger Levels
2 cage clamp terminals. Dedicated trigger signal analog
input and analog trigger level set-point input
Control I/O
5 cage-clamp terminals. Includes clock/trigger control
signals, +5 VDC output and digital ground
Digital I/O
24 cage-clamp terminals. Arranged as two groups of twelve
terminals.
Drain Wire Termination
3 cage-clamp terminals connected to chassis ground for
termination of ribbon cable shield drain wires. PCB spade
terminal for user connection to chassis.
POWER REQUIREMENTS
+5 V from PC bus via control I/O connector. Current required
per EX206 without custom modules or excitation of external
sensors is <240 mA. The ±15 V rails are derived from on board
DC to DC converter. All lines filtered
Optional external power +5 VDC and/or ±15 VDC
EX206
Page v
PHYSICAL
Mounted external to the host PC
Removable universal mounting feet for popular types of rails
Bench or panel mounted, stackable with EX201
A.2
Approximate Panel Dimensions
Unpacked
Packed
Width
Length
Height
240mm
420mm
90mm
125 mm
370 mm
50 mm
Environmental Conditions
The EX206 is designed to operate in a normal industrial environment when housed in a marshalling
cabinet or other fully shielded enclosure to maintain electro-magnetic compatibility. The unit must be
protected from settlement of moisture, dust or other particles and from any corrosive atmosphere.
Specific conditions are:
Temperature Range
Operating
Storage
Relative Humidity
5% to 90% Non condensing
Airflow
Still air for best isothermal performance
Dissipation
Each EX206 (without custom headers) will dissipate a maximum
of 1.2 Watts of heat
Mounting Rails
Carrier rails DIN/ES TS 32 or TS 35
Wiring Access
Side clearance of 100 mm on both sides should be allowed for
proper dressing of the incoming signal cables
Positioning
The EX206 is normally connected to the host computer by
cables of length 1.0 or 2.0 m. Longer cables can be
constructed, but may result in degradation of performance.
Interconnection to EX201 Expansion Panels mounted in the
same area is normally by 0.5 m cables
Handling
Normal static handling precautions apply
A.3
0 to 55° C
-20 to +70° C
Optional Accessories
Cable Options (Non EMC Compliant)
Order Code
Function
Position
Nominal Length
919 254 50
40 way (20 twisted pairs)
IDC Signal Cable
Any board interconnect.
0.5 m
919 254 52
40 way (20 twisted pairs)
IDC Signal Cable
Host PC board to first EX201/5/6
1.0 m
Page vi
EX206
919 254 54
40 way (20 twisted pairs)
IDC Signal Cable
Host PC board to first EX201/5/6
2.0 m
919 254 56
14 way IDC Control Cable
Any board interconnect.
0.5 m
919 254 58
14 way IDC Control Cable
Host PC board to first EX201/5/6
1.0 m
919 254 60
14 way IDC Control Cable
Host PC board to first EX201/5/6
2.0 m
919 254 62
26 way IDC Digital I/O Cable
Host PC226/230 to EX205
1.5 m
919 254 64
26 way IDC Digital I/O Cable
Host PC226/230 to EX205
2.5 m
919 254 66
5 way power cable
Any board interconnect.
0.5 m
919 254 68
5 way power cable (Tails)
Power supplies to first EX201/5/6 2.0 m
919 254 90
EX204 Digital I/O Adapter
PC rear panel termination
PC Internal
Cable Options (EMC Compliant)
Order Code
Function
Position
Nominal Length
909 561 58
44 way (hi-density) screened
cable
Host PC226E to EX202
1.0 m
909 561 59
15 way (hi-density) screened
cable
Host PC226E to EX202
1.0 m
909 561 09
37 way screened cable
Host EX203 to EX202
1.0 m
919 562 43
EX203 Digital I/O Adapter for
PC226E
PC rear panel termination
PC internal
919 561 73
EX202 I/O Panel for PC226E
Remote panel
Header Options
Order Code
Function
Features
919 254 70
Custom configuration header
Blank
919 254 75
Thermocouple input header
Open circuit detector and filter
919 254 80
4 - 20 mA current input header
25Ω precision resistor and filter
919 254 85
Input Multiplexer protection header
Dual polarity diode protection
EX206
Page vii
APPENDIX B
-
ANALOG CHANNELS ADDRESS LIST
The complete list of analog input and reference channels for a fully expanded Data Acquisition System.
The channels are addressed by bits 7 - 0 of the Control Register and Auxiliary 2 Control Bit (bit 14)
must be '0'. When this Aux. 2 bit is high, the trigger level table in appendix C applies.
EX205/6 LEVEL 0
EX201 LEVEL 2
EX201 LEVEL 4
EX201 LEVEL 6
CHANNEL Nº CHAN
HEX DEC
ID
CHANNEL Nº CHAN
HEX DEC
ID
CHANNEL Nº CHAN
HEX DEC
ID
CHANNEL Nº CHAN
HEX DEC
ID
00
01
02
03
04
05
06
07
08
09
0A
0B
0C
0D
0E
0F
10
11
12
13
14
15
16
17
18
19
1A
1B
1C
1D
1E
1F
000
001
002
003
004
005
006
007
008
009
010
011
012
013
014
015
016
017
018
019
020
021
022
023
024
025
026
027
028
029
030
031
00
01
02
03
04
05
06
07
08
09
10
11
12
13
14
15
CJ0
CJ1
CJ2
CJ3
CJ4
CJ5
CJ6
CJ7
VR0
VR1
VR2
VR3
VR4
VR5
VR6
VR7
EX201 LEVEL 1
20
21
22
23
24
25
26
27
28
29
2A
2B
2C
2D
2E
2F
30
31
32
33
34
35
36
37
38
39
3A
3B
3C
3D
3E
3F
Page viii
032
033
034
035
036
037
038
039
040
041
042
043
044
045
046
047
048
049
050
051
052
053
054
055
056
057
058
059
060
061
062
063
00
01
02
03
04
05
06
07
08
09
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
40
41
42
43
44
45
46
47
48
49
4A
4B
4C
4D
4E
4F
50
51
52
53
54
55
56
57
58
59
5A
5B
5C
5D
5E
5F
064
065
066
067
068
069
070
071
072
073
074
075
076
077
078
079
080
081
082
083
084
085
086
087
088
089
090
091
092
093
094
095
00
01
02
03
04
05
06
07
08
09
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
EX201 LEVEL 3
60
61
62
63
64
65
66
67
68
69
6A
6B
6C
6D
6E
6F
70
71
72
73
74
75
76
77
78
79
7A
7B
7C
7D
7E
7F
096
097
098
099
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
00
01
02
03
04
05
06
07
08
09
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
80
81
82
83
84
85
86
87
88
89
8A
8B
8C
8D
8E
8F
90
91
92
93
94
95
96
97
98
99
9A
9B
9C
9D
9E
9F
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
00
01
02
03
04
05
06
07
08
09
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
EX201 LEVEL 5
A0
A1
A2
A3
A4
A5
A6
A7
A8
A9
AA
AB
AC
AD
AE
AF
B0
B1
B2
B3
B4
B5
B6
B7
B8
B9
BA
BB
BC
BD
BE
BF
EX206
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
00
01
02
03
04
05
06
07
08
09
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
C0
C1
C2
C3
C4
C5
C6
C7
C8
C9
CA
CB
CC
CD
CE
CF
D0
D1
D2
D3
D4
D5
D6
D7
D8
D9
DA
DB
DC
DD
DE
DF
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
00
01
02
03
04
05
06
07
08
09
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
EX201 LEVEL 7
E0
E1
E2
E3
E4
E5
E6
E7
E8
E9
EA
EB
EC
ED
EE
EF
F0
F1
F2
F3
F4
F5
F6
F7
F8
F9
FA
FB
FC
FD
FE
FF
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
00
01
02
03
04
05
06
07
08
09
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
APPENDIX C
-
TRIGGER LEVEL SETTINGS LIST
The complete list of trigger levels for channel 0 analog trigger operations. The levels are set up by bits
7 - 0 of the Control Register and Auxiliary 2 Control Bit (bit 14) must be '1'. When this Aux. 2 bit is low,
the address table in appendix B applies.
NOMINAL TRIGGER LEVEL mV
Set Point
Magnitude
Bits 4- 0
00000
00001
00010
00011
00100
00101
00110
00111
01000
01001
01010
01011
01100
01101
01110
01111
10000
10001
10010
10011
10100
10101
10110
10111
11000
11001
11010
11011
11100
11101
11110
11111
Gain = 1000
Bits 7, 6 = 11
Bit 5 = 1 Bit 5 = 0
(+ve)
(–ve)
0.0
0.3125
0.625
0.9375
1.250
1.5625
1.875
2.1875
2.500
2.8125
3.125
3.4375
3.750
4.0625
4.375
4.6875
5.000
5.3125
5.625
5.9375
6.250
6.5625
6.875
7.1875
7.500
7.8125
8.125
8.4375
8.750
9.0625
9.375
9.6875
–10.000
–9.6875
–9.375
–9.0625
–8.750
–8.4375
–8.125
–7.8125
–7.500
–7.1875
–6.875
–6.5625
–6.250
–5.9375
–5.625
–5.3125
–5.000
–4.6875
–4.375
–4.0625
–3.750
–3.4375
–3.125
–2.8125
–2.500
–2.1875
–1.875
–1.5625
–1.250
–0.9375
–0.625
–0.3125
Gain = 100
Bits 7, 6 = 10
Bit 5 = 1 Bit 5 = 0
(+ve)
(–ve)
0.0
3.125
6.25
9.375
12.50
15.625
18.75
21.875
25.00
28.125
31.25
34.375
37.50
40.625
43.75
46.875
50.00
53.125
56.25
59.375
62.50
65.625
68.75
71.875
75.00
78.125
81.25
84.375
87.50
90.625
93.75
96.875
–100.00
–96.875
–93.75
–90.625
–87.50
–84.375
–81.25
–78.125
–75.00
–71.875
–68.75
–65.625
–62.50
–59.375
–56.25
–53.125
–50.00
–46.875
–43.75
–40.625
–37.50
–34.375
–31.25
–28.125
–25.00
–21.875
–18.75
–15.625
–12.50
–9.375
–6.25
–3.125
Gain = 10
Bits 7, 6 = 01
Bit 5 = 1 Bit 5 = 0
(+ve)
(–ve)
0.0
31.25
62.5
93.75
125.0
156.25
187.5
218.75
250.0
281.25
312.5
343.75
375.0
406.25
437.5
468.75
500.0
531.25
562.5
593.75
625.0
656.25
687.5
718.75
750.0
781.25
812.5
843.75
875.0
906.25
937.5
968.75
–1000.0
–968.75
–937.5
–906.25
–875.0
–843.75
–812.5
–781.25
–750.0
–718.75
–687.5
–656.25
–625.0
–593.75
–562.5
–531.25
–500.0
–468.75
–437.5
–406.25
–375.0
–343.75
–312.5
–281.25
–250.0
–218.75
–187.5
–156.25
–125.0
–93.75
–62.5
–31.25
Gain = 1
Bits 7, 6 = 00
Bit 5 = 1 Bit 5 = 0
(+ve)
(–ve)
0.0
312.5
625
937.5
1250
1562.5
1875
2187.5
2500
2812.5
3125
3437.5
3750
4062.5
4375
4687.5
5000
5312.5
5625
5937.5
6250
6562.5
6875
7187.5
7500
7812.5
8125
8437.5
8750
9062.5
9375
9687.5
–10000
–9687.5
–9375
–9062.5
–8750
–8437.5
–8125
–7812.5
–7500
–7187.5
–6875
–6562.5
–6250
–5937.5
–5625
–5312.5
–5000
–4687.5
–4375
–4062.5
–3750
–3437.5
–3125
–2812.5
–2500
–2187.5
–1875
–1562.5
–1250
–937.5
–625
–312.5
NOTE
In order to minimise the possibility of rogue triggers, it may be necessary to employ screened
cables and additional filtering especially in noisy operating enviroments. The above table
indicates nominal values and will change depending upon the frequency of the triggering signal.
The DAC accuracy is less than ½ LSB while the trigger window is typically ± 20 mV.
EX206
Page ix
APPENDIX D
GLOSSARY OF TERMS
The following glossary explains some terms used in this manual and in data acquisition applications.
Active Filter: An electronic filter that combines active circuit devices with passive circuit elements such as
resistors and capacitors. Active filters typically have characteristics that closely match ideal filters.
ADC (A/D): Analog to Digital Converter. q.v.
Alias Frequency: A false lower frequency component that appears in analog signal reconstructed from original
data acquired at an insufficient sampling rate.
Algorithm: A set of rules, with a finite number of steps, for solving a mathematical problem. An algorithm can be
used as a basis for a computer program.
Analog to Digital Converter (ADC): A device for converting an analog voltage to a parallel digital word where
the digital output code represents the magnitude of the input signal. See ‘Successive Approximation’.
Analog Switch: An electronic, single pole, two way switch capable of handling the full range of analog signal
voltage, and operating under the control of a logic signal.
Array: Data arranged in single or multidimensional rows and columns.
ASCII: American Standard Code for Information Interchange. A code that is commonly used to represent
symbols in computers.
Assembler: A program that converts a list of computer instructions written in a specific assembly language
format that can be executed by a specific processor.
Bandpass Filter: A type of electrical filter that allows a band of signals between two set frequencies to pass,
while attenuating all signal frequencies outside the bandpass range.
Base Address: A unique address set up on an I/O card to allow reference by the host computer. All registers are
located by an offset in relation to the base address.
BASIC: The most common computer language. BASIC is an acronym for Beginners All-purpose Symbolic
Instruction Code. BASIC is not rigorously structured and relies on English-like instructions which account for its
popularity.
Binary Coded Decimal (BCD): A system of binary numbering where each decimal digit 0 through 9 is
represented by a combination of four bits.
BIOS: Basic Input Output System. BIOS resides in ROM on a computer system board and provides device level
control for the major I/O devices on the system.
Bipolar: A signal being measured is said to be bipolar when the voltage on its 'high' terminal can be either of
positive or negative polarity in relation to its 'low' terminal.
Bit: Contraction of binary digit. The smallest unit of information. A bit represents the choice between a one or
zero value (mark or space in communications technology).
Buffer: A storage device used to compensate for a difference in rate of data flow, or time of occurrence of
events, when transferring data from one device to another. Also a device without storage that isolates two
circuits.
Bus: Conductors used to interconnect individual circuitry in a computer. The set of conductors as a whole is
called a bus.
Byte: A binary element string operated on as a unit and usually shorter than a computer word. Normally eight
bits.
C: A high level programming language, developed around the concept of structured programming and designed
for high operating speeds. Microsoft 'C' and Turbo 'C' are dialects of C.
Channel: One of several signal/data paths that may be selected.
Character: A letter, figure , number, punctuation or other symbol contained in a message or used in a control
function.
Code: A set of unambiguous rules specifying the way in which characters may be represented.
Conversion Time: The time required for a complete conversion of a value from analog to digital form (ADC) or
analog to digital form (DAC). Inverse of Conversion Rate.
Cold Junction: See Thermocouple Reference Junction
Cold Junction Compensation (CJC): A technique to compensate for thermocouple measurement offset when
the reference or cold junction is at a temperature other than 0° C.
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Common Mode Rejection Ratio (CMR): A measure of the equipment's ability to reject common mode
interference. Usually expressed in decibels as the ratio between the common mode voltage and the error in the
reading due to this common mode voltage.
Common Mode Voltage: In a differential measurement system, the common mode voltage usually represents
an interfering signal. The common mode voltage is the average of the voltages on the two input signal lines with
respect to ground level of the measuring system.
Comparator: An electronic circuit used to compare two values and set an indicator that identifies which value is
greater.
Compiler: High level language used to pre-process a program in order to convert it to a form that a processor
can execute directly.
Contact Closure: The closing of a switch, often controlled by an electromagnetic or solid state relay.
Conversion Time: The time required, in an analog/digital input/output system, from the instant that a channel is
interrogated (such as with a read instruction) to the moment that accurate an accurate representation of the data
is available. This could include switching time, settling time, acquisition time , converter processing time etc.
Counter: In software, a memory location used by a program for the purpose of counting certain occurrences. In
hardware, a circuit that can count pulses.
Counter/Timer Device: Converts time-dependent digital signals to a form that can be further processed by the
host PC. Typical functions include pulse counting, frequency and pulse width measurement. This can relate to
time, number of events, speed etc.
Crosstalk: A phenomenon in which a signal in one or more channels interferes with a signal or signals in other
channels.
Current Loop:
(a) Data communications method using presence or absence of current to signal logic ones
and zeros.
(b) A method of analog signal transmission where the measured value is represented by a
current. The common current loop signal is in the range 4 to 20 mA, but other standards
include 1 to 5 mA or 10 to 50 mA.
DAC (D/A): Digital to Analog Converter. q.v.
Data Acquisition or Data Collection: Gathering information from sources such as sensors and transducers in
an accurate, timely and organised manner.
Debouncing: Either a hardware circuit or software delay to prevent false inputs from a bouncing relay or switch
contact.
Decibel (dB): A logarithmic representation of the ratio between two signal levels.
Digital Signal: A discrete or discontinuous signal; one whose various states are identified with discrete levels or
values.
Digital to Analog Converter: A device for converting a parallel digital word to an analog voltage, where the
magnitude of the output signal represents the value of the digital input.
DIP Switch: A set of switches contained in a dual in line package.
Drift: Small variations in a measured parameter over a period of time.
Drivers: Part of the software that is used to control a specific hardware device.
Expansion Slots: The spaces provided in a computer for expansion boards that enhance the basic operations of
the computer.
GAL (Generic Array Logic): Programmable logic device where the architecture and functionality of each output
is defined by the system designer.
Handshaking: Exchange of predetermined codes and signals between two data devices to establish and control
a connection.
Hardware: The visible parts of a computer system such as the circuit boards, chassis, peripherals, cables etc. It
does not include data or computer programs.
Hexadecimal (Hex): A numbering system to the base 16.
Input/Output (I/O): The process of transferring data from or to a computer system including communication
channels, operator interface devices or data acquisition and control channels.
Interface: A shared boundary defined by common physical interconnection characteristics, signal characteristics
and meanings of interchanged signals.
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Interrupt: A computer signal indicating that the CPU should suspend its current task to service a designated
activity.
I/O Address: A method that allows the CPU to distinguish between different boards and I/O functions in a
system. See Base Address.
Least Significant Bit (LSB): In a system in which a numerical magnitude is represented by a series of digits, the
least significant bit (binary digit) is the digit that carries the smallest value or weight.
Linearity: Compliance with a straight line law between the input and output of a device.
Micro Channel Architecture (MCA): A unique architecture defined by IBM™ to provide a standard input/output
bus for Personal System computers.
Monotonic: A DAC is said to be monotonic if the output increases as the digital input increases, with the result
that the output is always a single valued function of the input.
Most Significant Bit (MSB): In a system in which a numerical magnitude is represented by a series of digits, the
least significant bit (binary digit) is the digit that carries the greatest value or weight.
Multiplexer: A multiple way analog switch q.v., where a single path through the switch is selected by the value
of a digital control word.
Noise: An undesirable electrical interference to a signal.
Normal Mode Signal: Aka Series mode signal. In a differential analog measuring system, the normal mode
signal is the required signal and is the difference between the voltages on the two input signal lines with respect
to ground level of the measuring system.
Offset:
(a)
A fixed, known voltage added to a signal.
(b) The location of a register above the base address.
Pascal: A high level programming language originally developed as a tool for teaching the concepts of
structured programming. It has evolved into a powerful general-purpose language popular for writing scientific
and business programs. Borland Turbo Pascal is a dialect of Pascal.
Passive Filter: A filter circuit using only resistors, capacitors and inductors.
PC: Personal Computer (Also printed circuit)
Port: An interface on a computer capable of communication with another device.
Range: Refers to the maximum allowable full-scale input or output signal for a specified performance.
Real Time: Data acted upon immediately instead of being accumulated and processed at a later time.
Repeatability: The ability of a measuring system to give the same output or reading under repeated identical
conditions.
Resolution: A binary converter is said to have a resolution of n-bits when it is able to relate 2n distinct analog
values to the set of n-bit binary words.
RTD (Resistive Temperature Device): An electrical circuit element characterised by a defined coefficient of
resistivity.
Sample/Hold: A circuit which acquires an analog voltage and stores it for a period of time.
Sensor: Device that responds to a physical stimulus (heat, light, sound, pressure, motion etc.) producing a
corresponding electrical output.
Settling Time: The time taken for the signal appearing at the output of a device to settle to a new value caused
by a change of input signal.
Signal to Noise Ratio: Ratio of signal level to noise in a circuit. Normally expressed in decibels.
Simultaneous Sample/Hold: A data acquisition system in which several sample/hold circuits are used to
simultaneously sample a number of analog channels and hold these values for sequential conversion. One
sample/hold circuit per analog channel is required.
Software: The non-physical parts of a computer system that includes computer programs such as the operating
system, high level languages, applications program etc.
Spike: A transient disturbance of an electrical circuit.
Stability: The ability of an instrument or sensor to maintain a consistent output when a consistent input is
applied.
Successive Approximation: An analog to digital conversion method that sequentially compares a series of
binary weighted values with the analog input signal to produce an output digital word in ‘n’ steps where ‘n’ is the
number of bits of the A/D Converter. q.v.
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Symbol: The graphical representation of some idea. Letters and numerals are symbols.
Syntax: Syntax is the set of rules used for forming statements in a particular programming language.
Thermocouple: A thermocouple is two dissimilar electrical conductors, known as thermo-elements, so joined as
to produce a thermal emf when the measuring and reference junctions are at different temperatures.
Thermocouple Measuring Junction: The junction of a thermocouple which is subjected to the temperature
being measured.
Thermocouple Reference Junction: The junction of a thermocouple which is at a known temperature. aka
Cold Junction.
Throughput Rate: The maximum repetitive rate at which a data conversion system can operate with a specified
accuracy. It is determined by summing the various times required for each part of the system and then taking the
reciprocal of this time.
Transducer: Device that converts length, position, temperature, pressure, level or other physical variable to an
equivalent voltage or current accurately representing the original measurement.
Trigger: Pulse or signal used to start or stop a particular action. Frequently used to control data acquisition
processes.
Triggering Window: Tolerance which applies to the comparator input when using the EX206's analog trigger.
The triggering window specifies the deviation between the point at which the trigger level is set and the actual
triggering point.
Unipolar: A signal being measured is said to be unipolar when the voltage on its 'high' terminal is always the
same polarity (normally positive) in relation to its 'low' terminal.
Word: The standard number of bits that can be manipulated at once. Microprocessors typically have word
lengths of 8, 16 or 32 bits.
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APPENDIX E
ASSEMBLY DRAWING
Full circuit diagrams and layout drawings of the EX206 Termination Panel are available upon request.
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