Allen-Bradley 1771-OFE User manual

Analog Output Module
Cat. No. 1771OFE
User Manual
Allen-Bradley PLCs

Because of the variety of uses for the products described in this
publication, those responsible for the application and use of this control
equipment must satisfy themselves that all necessary steps have been taken
to assure that each application and use meets all performance and safety
requirements, including any applicable laws, regulations, codes
and standards.
The illustrations, charts, sample programs and layout examples shown in
this guide are intended solely for example. Since there are many variables
and requirements associated with any particular installation, Allen-Bradley
does not assume responsibility or liability (to include intellectual property
liability) for actual use based upon the examples shown in this publication.
Allen-Bradley publication SGI-1.1, “Safety Guidelines For The
Application, Installation and Maintenance of Solid State Control”
(available from your local Allen-Bradley office) describes some important
differences between solid-state equipment and electromechanical devices
which should be taken into consideration when applying products such as
those described in this publication.
Reproduction of the contents of this copyrighted publication, in whole or
in part, without written permission of Allen-Bradley Company, Inc.
is prohibited.
Throughout this manual we make notes to alert you to possible injury to
people or damage to equipment under specific circumstances.
ATTENTION: Identifies information about practices or
circumstances that can lead to personal injury or death, property
damage or economic loss.
Attention helps you:
Identify a hazard.
Avoid the hazard.
Recognize the consequences.
Important: Identifies information that is especially important for
successful application and understanding of the product.
Important: We recommend you frequently backup your application
programs on appropriate storage medium to avoid possible data loss.
Important User Information

Summary of Changes
SI
Summary of Changes
This release of the publication contains updated information from the last
release.
Updated Information
This manual has been revised and reformatted to make the manual more
usable.
To help you find new and updated information in this release of the
publication, we have included change bars as shown to the right of this
paragraph.
Summary of Changes
Allen-Bradley PLCs

Summary of Changes SI . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Preface P1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Manual's Purpose P1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Audience P1
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Vocabulary P1
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Manual Organization P1
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Related Products P2
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Product
Compatibility P2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Overview of the Analog Output Module 11. . . . . . . . . . . . . . .
Chapter Objectives 11. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Module Description 11
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
How Analog Modules Communicate with Programmable Controllers 12
Accuracy 13. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Chapter Summary 13
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Module Installation 21. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Chapter Objectives 21. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Before Y
ou Install Y our Analog Module 21. . . . . . . . . . . . . . . . . . . . .
Calculating Power Requirements 21
. . . . . . . . . . . . . . . . . . . . . . . . .
Determine Module Location in the I/O Chassis 22
. . . . . . . . . . . . . . .
Setting Module Configuration Jumpers 22
. . . . . . . . . . . . . . . . . . . . .
Connecting Wiring 29
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Interpreting the Indicator Lights 211
. . . . . . . . . . . . . . . . . . . . . . . . . .
Chapter Summary 211
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Module Configuration 31. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Chapter Objectives 31. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Configuring Your Module 31
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Configuration Word 33
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Default
Configuration 34. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Data Format 34
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Scaling 36
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Procedure for Configuring Your Module 39
. . . . . . . . . . . . . . . . . . . .
Chapter Summary 39
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Table of Contents

Table of Contentsii
Module Programming 41. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Chapter Objectives 41. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Block Transfer with the Analog Output Module 41
. . . . . . . . . . . . . . .
Block Transfer Programming Formats 41
. . . . . . . . . . . . . . . . . . . . .
Block Transfer Programming  PLC2 Family Processors Only 42
. . . .
Block Transfer Programming  PLC3 Family Processors Only 46
. . . .
Block Transfer Programming  PLC5 Family Processors Only 48
. . . .
Other Programming Considerations 410
. . . . . . . . . . . . . . . . . . . . . . .
System Expansion Recommendations  PLC2 Processors Only 413
. .
Chapter Summary 413
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Module Status and Input Data 51. . . . . . . . . . . . . . . . . . . . . .
Chapter Objectives 51. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Reading Data from the Module 51
. . . . . . . . . . . . . . . . . . . . . . . . . .
Chapter Summary 52
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Calibrating Y our Output Module 61. . . . . . . . . . . . . . . . . . . . .
Chapter Objectives 61. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Tools and T
est Equipment 61. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Calibrating Your Module 61
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Voltage
Output V ersion (1771OFE1) 62. . . . . . . . . . . . . . . . . . . . . .
Current
Output V ersion (1771OFE2) 66. . . . . . . . . . . . . . . . . . . . . .
Current
Output V ersion (1771OFE3) 610. . . . . . . . . . . . . . . . . . . . . .
Chapter Summary 612
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Diagnostics and Troubleshooting 71. . . . . . . . . . . . . . . . . . .
Chapter Objectives 71. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Interpreting the Indicator Lights 71
. . . . . . . . . . . . . . . . . . . . . . . . . .
Read Block Transfer Status Words 72
. . . . . . . . . . . . . . . . . . . . . . .
Chapter Summary 73
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Specifications A1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Block Transfer with MiniPLC2 and PLC2/20 Processors B1.
Multiple GET Instructions B1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Setting the Block Length (Multiple GET Instructions Only) B3
. . . . . . .
Data Table Formats C1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4Digit Binary Coded Decimal (BCD) C1. . . . . . . . . . . . . . . . . . . . . .
Signedmagnitude Binary C2
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Two's Complement Binary C3
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Allen-Bradley PLCs

Preface
P-1
Preface
This manual shows you how to use the analog output module with an
Allen-Bradley programmable controller. It describes methods for
installing, programming, calibrating, and troubleshooting your module.
To make efficient use of your module, you must be able to program and
operate an Allen-Bradley programmable controller. In particular, you must
be able to program block transfer instructions.
In this manual we assume that you know how to do this. If you do not,
refer to the appropriate programming and operations manual for the
processor that you are using.
In this manual we refer to the:
Analog Output Module (cat. no. 1771-OFE) as the “output module”
Programmable Controller as the “processor” or “controller.”
The manual is divided into seven chapters. The following chart shows
each chapter with its corresponding title and a brief overview of the topics
covered in that chapter.
Chapter Title Topics Covered
1Introduction and
Product Description
Description of the module, including general and
hardware features. How modules communicate with
programmable controllers
2Module Installation Power requirements, keying, module location and hard
ware configuration
3Module Configuration Software configurations, output range selection, data
format and data scaling
4Module Programming
Writing data to the module, and other programming
considerations (default block length, block transfer
boundary word, and watchdog timer)
5Module Status and Input Data Reading data from the module
6 Calibration Calibration Procedures
7Diagnostics and Troubleshooting Troubleshooting Guide for Problem Diagnosis
Manual's Purpose
Audience
Vocabulary
Manual Organization

Preface
P-2
Appendices Title
A Specifications
BBlock Transfer with MiniPLC2 and PLC2/20 Processors
CData Formats
You can install your output module in any system that uses Allen-Bradley
programmable controllers that have block transfer capabilities and the
1771 I/O structure.
For more information on your programmable controllers, contact your
nearest Allen-Bradley office.
The 1771-OFE module can be used with any 1771 I/O chassis.
Communication between the discrete analog module and the processor is
bidirectional; the processor block-transfers output data through the output
image table to the module and block-transfers input data from the module
through the input image table. The module also requires an area in the data
table to store the read block transfer data and write block transfer data. I/O
image table use is an important factor in module placement and addressing
selection. Compatibility and data table use is listed in the following table.
Table P.A
Compatibility
and Use of Data T able
Use of Data Table Compatibility
Catalog
Number Input
Image
Output
Image
Read
Block
Write
Block
Addressing Chassis
Number
Image
Bits
Image
Bits
Block
Words
Block
Words 1/2Slot 1Slot 2Slot
Chassis
Series
1771OFE 8 8 5 13 Y Y Y A, B
A = Compatible with 1771A1, A2, A4
B = Compatible with 1771A1B, A2B, A3B, A3B1, A4B
Y = Compatible without restriction.
You can place your module in any I/O module slot of the I/O chassis.
You can put two output modules in the same module group.
Do not put the module in the same module group as a discrete high
density module.
Avoid placing output modules close to ac modules or high voltage dc
modules.
For a list of publications with information on Allen-Bradley programmable
controller products, consult our publication index (SD499).
Related Products
Product Compatibility
Related Publications
Allen-Bradley PLCs

Chapter 1
1-1
Overview of the Analog Output Module
In this chapter, you will read about:
module features
how analog modules communicate with programmable controllers
module output ranges
The Analog Output Module (cat. no. 1771-OFE) is an intelligent block
transfer module that converts binary or four-digit BCD values (supplied by
your processor) to analog signals at its four module outputs. The module
accomplishes the data transfer with block transfer programming.
Block transfer write (BTW) programming moves up to 13 words of data
from the processor to the module for digital to analog (D/A) conversion in
one program scan. This information is converted to analog signals and is
sent to the appropriate output channels.
A block transfer read (BTR) moves five words of data from the module to
the processor data table, if desired, for diagnostic purposes. The BTR is
discussed in Chapter 7, “Diagnostics and Troubleshooting.”
The module has a scaling feature that converts data sent to the module in
engineering units to the proper analog signals.
You may connect up to four analog output devices--such as valve
positioners, motor speed controllers, signal converters or recorders--to the
analog output module’s four channels. All analog output device inputs
should conform to the voltage or current ratings of each module
output channel.
Module Features
In the programmable controller system, the analog output module provides
the following functions:
four individually isolated differential outputs
selectable scaling to engineering units
selectable data format
selectable voltage ranges (1771-OFE1 only)
no external power required--power is drawn from the 1771 I/O chassis
backplane.
requires only one I/O slot
Chapter Objectives
Module Description

Overview of the Analog Output Module
Chapter 1
1-2
Output Ranges
There are three versions of the analog output module:
Catalog Number Module Output Output Range
1771OFE1 Voltage
15V dc
010V dc
+10V dc
Selected by
configuration
jumpers
1771OFE2 Current 420mA Factory set
1771OFE3 Current 050mA Factory set
The voltage version (1771-OFE1) voltage output range is selected with
configuration jumpers in the module:
Note: The 1771-OFE1 is shipped with the selection jumpers in the
+10V position.
The current output versions (1771-OFE2 and -OFE3) are factory set.
The processor transfers data to the module (block transfer write) and from
the module (block transfer read) using BTW and BTR instructions in your
ladder diagram program. These instructions let the processor send output
values to the module, establish the module’s mode of operation
(Figure 1.1) and receive status information from the module.
Figure 1.1
Communication
Between Processor and Module
+
–
2
13
To analog output devices
BTW
Programmable
Controller Analog Output Module
Cat. No. 1771OFE
12876
BTR
4
5
1. The processor transfers your configuration and output data to the
module via a block transfer write instruction.
How Analog Modules
Communicate with
Programmable Controllers
Allen-Bradley PLCs

Overview of the Analog Output Module
Chapter 1
1-3
2. The module converts the data into proportional voltage or current
outputs.
3. These module outputs drive external analog devices.
4. When instructed by your ladder program, the processor performs a
read block transfer of output values and module status.
5. The processor and module determine that the transfer was made
without error.
6. Your ladder program can use and/or move the data (if valid) before it
is written over by the transfer of new data in a subsequent transfer.
The accuracy of your output module is described in Appendix A.
In this chapter you read about the functional aspects of the output module
and how the module communicates with the programmable controller.
Accuracy
Chapter Summary

Chapter 2
2-1
Module Installation
In this chapter, you will read how to:
install your module in the I/O Chassis
set module configuration jumpers
Read this installation chapter completely before you install your module.
Double check all connections and option selections before you begin
programming your module.
Installing your output module is a relatively simple task, but certain
preparations must be made before you actually install it. You must:
calculate the power requirements of the output module and other
modules in each chassis
determine the location of the modules in the I/O chassis
set module configuration plugs
key the backplane connectors in the I/O chassis
wire the field wiring arm
ATTENTION: To avoid injury to personnel and damage to
equipment, disconnect and lockout all ac power supplies before
installing and wiring the output module.
The analog output module receives its power through the 1771 I/O chassis
backplane from the chassis power supply. It does not require any other
external power supply. When planning your system, you must consider the
power usage of all modules in the I/O chassis to prevent overloading the
I/O chassis backplane and/or power supply. Add this to the requirements
of all other modules in the I/O chassis.
Analog Module Power Requirement
1771OFE1
15A@5Vdc
1771OFE2 1.5A @ 5V dc
1771OFE3 2.5A @ 5V dc
Chapter Objectives
Before You Install Your
Analog Module
Calculating Power
Requirements
Allen-Bradley PLCs

Module Installation
Chapter 2
2-2
ATTENTION: Do not insert or remove modules from the I/O
chassis while system power is ON. Failure to observe this rule
could result in damage to module circuitry.
You can place your module in any I/O module slot of the I/O chassis with
the following guidelines:
Do not put the module in the same module group as a discrete
high-density module.
Avoid placing output modules close to ac modules or high-voltage dc
modules.
Group output modules together within an I/O chassis whenever possible
to minimize noise interference from other modules.
You can put two output modules in the same module group.
The module configuration jumpers consist of:
the last state configuration jumper (all versions)
the voltage range configuration jumpers (1771-OFE1 only).
Current Output Version
Current version modules (1771-OFE2 and -OFE3) have all configuration
jumpers installed and require no additional configuration. The
configuration jumper for the Last State mode output level is in the default
position (MID). Refer to the section entitled “Last State Output Levels”
for additional configuration information.
Voltage Output Version
If you are using the voltage output version, you need to set several
configuration jumpers on the module’s circuit board. You must set these
jumpers before you can proceed with configuring the module. When you
set these jumpers, you configure each channel for one of the three voltage
ranges listed above. The module is shipped with the plugs in the +10V
position.
Determine Module Location
in the I/O Chassis
Setting Module
Configuration Jumpers

Module Installation
Chapter 2
2-3
Important: You do not have to remove the module cover to set the LAST
STATE configuration jumper. You must remove the cover to select the
voltage range on the 1771-OFE1.
Last State Configuration Jumpers
The LAST STATE configuration jumpers determine the value of all the
module’s outputs whenever communication between the module and the
processor is lost. This condition occurs when a processor or adapter faults,
or the processor is placed in the PROG or TEST mode, or if the remote I/O
cable breaks.
This is a significant safety feature. You can choose to have the module’s
outputs go to the maximum, minimum, or middle of their respective ranges
or hold their last state if a module or system fault occurs or if the system
processor changes from RUN to PROG mode.
You do this by placing the LAST STATE configuration jumpers on eight
(four jumpers on sets of pins) of the stake pins marked MAX, MIN, MID
on the module’s circuit board (Figure 2.1). If you do not place
configuration jumpers in one of these positions, the module defaults to the
HOLD LAST VALUE setting.
Figure 2.1 shows jumper positions for the 1771-OFE, Series B, Analog
Output Module LAST STATE Configuration Jumpers.
Important: Ignore the MAX, MIN, MID markings on the printed circuit
board.
Important: On power-up, the module’s output is disabled until the module
receives the first block transfer write. The output then enables with the
value that you send it in the block transfer write block.
Important: We ship 1771-OFE modules with the LAST STATE
configuration jumpers in the MID position.
ATTENTION: Switch 1 of the I/O rack affects the function of
the configuration settings as indicated in the table below.
Rack Switch 1 Configuration Jumper Setting Rack Switch 1
Setting MIN MID MAX HOLD LAST STATE
Last State Last State Last State Last State Last State
Reset Min Mid Max Last State
Allen-Bradley PLCs

Module Installation
Chapter 2
2-4
Figure 2.1
LAST
ST A TE Configuration Jumper
Last State Output Level
Configuration Jumpers
MIN
MID
MAX
Front of Circuit Board
HOLD LAST ST ATE
Table 2.A lists the output ranges and their minimum, maximum, and
middle values.
Table 2.A
Output
Last State Configuration V alues
Output Range
Selection
Minimum
Value Middle Value Maximum Value
420mA 4mA 12mA 20mA
050mA 0mA 25mA 50mA
15V 1V 3V 5V
010V 0V 5V 10V
+10V 10V 0V +10V

Module Installation
Chapter 2
2-5
These output conditions are active only if the following conditions exist:
the module faults
the processor is in the PROGRAM or TEST mode
rack switch 1 is in the reset position
Rack switch 1 determines what output conditions occur during a rack fault.
Rack Switch 1 Configuration Jumper Setting
Rack Switch 1
Setting MIN MID MAX HOLD LAST STATE
Last State Last State Last State Last State Last State
Reset Min Mid Max Last State
To set the last state configuration jumpers, proceed as follows.
ATTENTION: Do not insert modules into or remove modules
from the I/O chassis while system power is ON. Failure to
observe this rule could result in damage to module circuitry and
unexpected machine operation.
1. Locate the jumpers as shown in Figure 2.1.
2. Carefully pull up on the jumpers to remove from the pins.
3. Reposition as necessary to provide the value selected in Table 2.A.
Allen-Bradley PLCs

Module Installation
Chapter 2
2-6
Setting Voltage Range Configuration Jumpers (1771OFE1 only)
If you ordered the voltage output version, you must set several
configuration jumpers located inside the module on the circuit board. To
do this, follow these steps:
1. Remove the covers from the module’s printed circuit board
(Figure 2.2).
Important: You do not have to remove the module cover to set the LAST
STATE configuration jumpers. You must remove the cover to select the
voltage range on the 1771-OFE1.
Figure 2.2
Module
Disassembly for V oltage Range Configuration Jumper Setting
Coverplate
FrontofModule
12879
Last State
Configuration Jumpers
Voltage Range
Configuration
Jumpers
Cover
(terminal
identification
side)
2. Locate the configuration jumpers and set them according to your
output voltage requirements (Figure 2.3).
3. Reassemble the module.

front of chassis
lockingbar pins
12453I
Module Installation
Chapter 2
2-7
Figure 2.3
Configuration
Jumper Locations
510
13 18
21 26
29 34
In
Out
P5
P6
P7
P8
P9
P10
In
In
Out
Out
Out
Out
0-10V +
-
Out
Out
In
In
Out
Out
1-5V
Out
Out
Out
Out
In
In
10V
Desired Voltage Range Output
Channel
1
P13
P14
P15
P16
P17
P18
2
P21
P22
P23
P24
P25
P26
3
P29
P30
P31
P32
P33
P34
4
In
In
Out
Out
Out
Out
Out
Out
In
In
Out
Out
Out
Out
Out
Out
In
In
In
In
Out
Out
Out
Out
Out
Out
In
In
Out
Out
Out
Out
Out
Out
In
In
In
In
Out
Out
Out
Out
Out
Out
In
In
Out
Out
Out
Out
Out
Out
In
In
LAST
ST ATE
(side view
of jumper)
11856I
Configuration
Jumper
Location
To install your module in an I/O chassis:
1. First, turn off power to the I/O chassis:
ATTENTION: Remove power from the 1771 I/O chassis
backplane and disconnect the cable from the module before
removing or installing an I/O module.
Failure to remove power from the backplane could cause injury
or equipment damage due to possible unexpected operation.
Failure to remove power from the backplane could cause
module damage, degradation of performance, or injury.
2. Lift the locking latch holding the module into the chassis. (On chassis
equipped with a chassis locking bar, pull the locking-bar pins to
release the locking bar and swing it up.)
Installing the Analog Module
Allen-Bradley PLCs

Module Installation
Chapter 2
2-8
3. Position the keying bands (Figure 2.4) in the backplane connectors to
correspond to the key slots on the module. This prevents you from
inserting the wrong module in this slot. This analog module uses:
between 10 and 12
between 26 and 28
ATTENTION: Observe the following precautions when
inserting or removing keys:
insert or remove keys with your fingers
make sure that key placement is correct
Incorrect keying or the use of a tool can result in damage to
the backplane connector and possible system faults.
You can change the position of these bands if subsequent system
design and rewiring makes insertion of a different type of module
necessary.
Figure 2.4
Keying
Positions
Upper Connector 11022I
ATTENTION: Insert or remove
keying bands with your fingers.
I/O chassis
Keying Bands
4. Place the module in the plastic tracks on the top and bottom of the
slot that guides the module into position.
5. Do not force the module into its backplane connector. Apply firm
even pressure on the module until it is firmly seated in the chassis.
Note: The chassis locking bar will not close if all modules are not
seated properly.

Module Installation
Chapter 2
2-9
6. Snap the chassis locking bar (or locking latch on earlier chassis) over
the top of the module to secure it. Make sure the locking pins on the
locking bar are fully engaged.
7. Connect the wiring to the module as explained under “Connecting
Wiring” below.
The analog devices connect to the analog module through a field wiring
arm (cat. no. 1771-WC). The field wiring arm pivots on the front of the
I/O chassis to connect with the module. You can remove the module from
the chassis without disconnecting user wiring because wiring connections
are made on the field wiring arm. The connection diagram (Figure 2.5)
shows connections to the field wiring arm.
Figure 2.5
Connection
of Analog Devices to the Field Wiring Arm (cat. no. 1771WC)
A
0
1
2
3
4
5
6
7
B
Channel 1 output (+) lead
Channel 1 output () lead
Channel 2 output (+) lead
Channel 2 output () lead
Channel 3 output (+) lead
Channel 3 output () lead
Channel 4 output (+) lead
Channel 4 output () lead
Not used
Not used
Ground
User
Analog
Device
12878
Field Wiring Arm
Cat. No 1771WC
NOTE: The 1771OFE module does not supply loop power for
looppowered analog devices (transmitters, transducers, etc.).
Loop power must be supplied by the user.
Usersupplied loop power
(if required)
ATTENTION: To avoid injury to personnel and damage to
equipment, disconnect and lockout ac power from the processor
and system power supplies before wiring the module.
Connecting W iring
Allen-Bradley PLCs

Module Installation
Chapter 2
2-10
The module requires shielded cable for signal transmission to the analog
devices. Use Belden 8761 or equivalent as described in the “Approved
Vendor List,” publication ICCG-2.2. This cable consists of a single
insulated, twisted-pair of conductors, covered along their entire length by a
foil shield and encased in plastic. The shield reduces the effect of induced
noise at any point along the cable.
You must ground the shield at the chassis end only. We recommend
connecting each output cable’s shield to a properly grounded common bus.
Figure 2.6
Cable
Grounding
19480
When you connect grounding conductors to the I/O chassis
grounding stud, place a star washer under the first lug, then
place a nut with captive lock washer on top of each ground lug.
Grounding Stud
1Use
the cup washer if crimpon lugs are not used.
Chassis Ground Singlepoint Grounding
Ground Lug
Nut
Ground Lug1
Star
Washer
I/O Chassis Side Plate
Nut and Captive
Washer
Externaltooth Washers
#10 Threadforming screw
19923
Refer to W iring and Grounding Guidelines, publication
17704.1 for additional information.