Allen-Bradley 1794-IE8 Series B User manual

User Manual
AllenBradley
FLEX I/O Analog
Modules
(Cat. No. 1794IE8, OE4,
and IE4XOE2 Series B)

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

Publication 17946.5.2 - May 1996
Summary of Changes
This publication contains new and revised information not included
in the previous version.
New Information
Addition of DeviceNet Mapping
A new chapter has been added to describe the special mapping for
DeviceNet.
Additional Flex I/O Modules
New series B analog modules are now available for Flex I/O users.
These modules are:
•1794-OE4 series B 4 output analog module
•1794-IE8 series B 8 input analog module
•1794-IE4XOE2 series B 4 in/2 out combo analog module
The differences between series A and series B are explained in
Appendix B.
I/O Mapping
I/O mapping for the series B versions of the analog modules has
been added.
Revised Information
This manual has been revised to include separate chapters for remote
I/O adapters and DeviceNet adapters. In addition, range selection bits
have been revised to include an Off condition.
Change Bars
The areas in this manual which are different from previous editions
are marked with change bars (as shown to the right of this paragraph)
to indicate the addition of new or revised information.

Summary of Changes P1. . . . . . . . . . . . . . . . . . . . . . . . . . . .
New Information P1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Addition of DeviceNet Mapping P1
. . . . . . . . . . . . . . . . . . . . . . . .
Additional
Flex I/O Modules P1. . . . . . . . . . . . . . . . . . . . . . . . . . .
I/O Mapping P1
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Revised
Information P1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Change Bars P1
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Using This Manual P-1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Purpose of this Manual P-1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Audience P-1
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Vocabulary P-1
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Manual Organization P-1
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Conventions P-2
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
For
Additional Information P-2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Overview of FLEX I/O and your Analog Modules 1-1. . . . . . . .
Chapter Objectives 1-1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
The
FLEX I/O System 1-1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Types
of FLEX I/O Modules 1-2. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
How
FLEX I/O Analog Modules Communicate
with Programmable Controllers 1-2. . . . . . . . . . . . . . . . . . . . . . .
Features of your Analog Modules 1-4
. . . . . . . . . . . . . . . . . . . . . . . .
Chapter Summary 1-4
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
How to Install Y our Analog Module 2-1. . . . . . . . . . . . . . . . . .
Chapter Objectives 2-1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Before Y
ou Install Y our Analog Module 2-1. . . . . . . . . . . . . . . . . . . . .
Compliance to European Union Directives 2-1
. . . . . . . . . . . . . . . . . .
EMC Directive 2-1
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Low V
oltage Directive 2-2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Power Requirements 2-2
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Installing the Module 2-4
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Mounting the T
erminal Base Unit on a DIN Rail 2-4. . . . . . . . . . . . .
Panel/Wall
Mounting 2-5. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Mounting the Analog Module on the T
erminal Base Unit 2-7. . . . . . .
Connecting Wiring for the Analog Modules 2-8
. . . . . . . . . . . . . . . . . .
Connecting Wiring using a 1794TB2 or TB3 T
erminal Base Unit 2-9
Module Indicators 2-13. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Chapter Summary 2-13
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Table of Contents

Table of Contentsii
Module Programming 3-1. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Chapter Objectives 3-1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Block Transfer Programming 3-1
. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Sample programs for Flex I/O Analog Modules 3-2
. . . . . . . . . . . . . . .
PLC3 Programming 3-2
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Figure 3.1
PLC3 Family Sample Program Structure for a 1794IE8 Module 3-2
Figure 3.2
PLC3 Family Sample Program Structure for a
1794OE4 Module 3-3
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Figure 3.3
PLC3 Family Sample Program Structure for a
1794IE4XOE2 Module 3-3
. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
PLC5 Programming 3-4
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Figure 3.4
PLC5 Family Sample Program Structure for the 1794IE8 3-4. . . .
Figure 3.5
PLC5 Family Sample Program Structure for the 1794OE4 3-4. . .
Figure 3.6
PLC5 Family Sample Program Structure for the 1794IE4XOE2 3-5
PLC2 Programming 3-5. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Analog Data Format 3-6
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Chapter Summary 3-6
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Writing Configuration to and Reading Status from
Your Module with a Remote I/O Adapter 4-1. . . . . . . . . . .
Chapter Objectives 4-1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Configuring Your Analog Module 4-1
. . . . . . . . . . . . . . . . . . . . . . . . .
Range
Selection 4-2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Safe
State V alue Selection 4-2. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Data Format 4-2
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Reading Data From Your Module 4-2
. . . . . . . . . . . . . . . . . . . . . . . . .
Mapping Data for the Analog Modules 4-3
. . . . . . . . . . . . . . . . . . . . .
8 Input Analog Module (Cat. No. 1794IE8 Series B) 4-3
. . . . . . . . .
Analog Input Module (1794IE8) Read 4-3
. . . . . . . . . . . . . . . . .
Word/Bit Descriptions for the 1794IE8 Analog
Input Module Read 4-4. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Analog Input Module (1794IE8/B) Write Configuration Block 4-4
.
Range Selection Bits for the 1794IE8/B Analog Input Module 4-5
Word/Bit Descriptions for the 1794IE8/B Analog Input
Module Write 4-5
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4 Output Analog Module (Cat. No. 1794OE4 Series B) 4-6
. . . . . . .
Analog Output Module (1794OE4/B) Read 4-6
. . . . . . . . . . . . .
Bit/Word Descriptions for the 1794OE4/B Analog Output
Module Read 4-6
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Analog Output Module (1794OE4/B) Write Configuration Block 4-7

Table of Contents iii
Range Selection Bits for the 1794OE4/B Analog Output
Module (Word 5) 4-7
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Word/Bit Descriptions for the 1794OE4/B Analog Output
Module Write 4-7
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4
Input/2 Output Analog Combo Module
(Cat. No. 1794IE4XOE2 Series B) 4-9. . . . . . . . . . . . . . . . . . .
Analog Combo Module (1794IE4XOE2/B) Read 4-9
. . . . . . . . .
Word/Bit Descriptions for the 1794IE4XOE2/B Analog Combo
Module Read 4-9. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Analog Combo Module (1794IE4XOE2/B) W
rite
Configuration Block 4-10. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Range Selection Bits for the 1794IE4XOE2/B Analog
Combo Module 4-11
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Word/Bit Descriptions for the 1794IE4XOE2/B Analog
Combo Module Write 4-11. . . . . . . . . . . . . . . . . . . . . . . . . . .
Chapter Summary 4-12
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
How Communication T akes Place and I/O Image
Table Mapping with the DeviceNet Adapter 5-1. . . . . . . . .
Chapter Objectives 5-1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
About DeviceNet Manager 5-1
. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Polled
I/O Structure 5-1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Adapter Input Status Word 5-2
. . . . . . . . . . . . . . . . . . . . . . . . . . .
Mapping
Data into the Image T able 5-3. . . . . . . . . . . . . . . . . . . . . . .
8 Input Analog Module (Cat. No. 1794IE8 Series B)
Image T able Mapping 5-3. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Analog Input Module (1794IE8/B) Read 5-3
. . . . . . . . . . . . . . .
Analog Input Module (1794IE8/B) Write 5-4
. . . . . . . . . . . . . . . .
Range Selection Bits for the 1794IE8/B Analog Input Module 5-4
Word/Bit Descriptions for the 1794IE8/B Analog Input Module 5-4
4 Output Analog Module (1794OE4 Series B) Image
Table Mapping 5-6
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Analog Output Module (1794OE4/B) Read 5-6
. . . . . . . . . . . . .
Analog Output Module (1794OE4/B) Write 5-6
. . . . . . . . . . . . . .
Range Selection Bits for the 1794OE4/B Analog Output
Module (Write Word 6) 5-7. . . . . . . . . . . . . . . . . . . . . . . . .
Word/Bit Descriptions for the 1794OE4/B Analog
Output Module 5-7. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Analog Combo Module (1794IE4XOE2 Series B)
Image T able Mapping 5-9. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Analog Combo Module (1794IE4XOE2/B) Read 5-9
. . . . . . . . .
Analog Output Module (1794IE4XOE2/B) Write 5-10
. . . . . . . . . .
Range Selection Bits for the 1794IE4XOE2 Analog
Combo Module 5-10
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Word/Bit Descriptions for the 1794IE4XOE2 Analog
Combo Module 5-10. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Defaults 5-12
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Table of Contentsiv
Specifications A-1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Differences Between Series A and Series B Analog Modules B-1
Data Table Formats C-1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Two's Complement Binary C-1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Analog Data Format C-2
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Scaling Example C-3
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Support Services C-1
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Technical Support C-1
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Engineering and Field Services C-1
. . . . . . . . . . . . . . . . . . . . . . . .
Technical Training C-1
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Repair and Exchange Services C-1
. . . . . . . . . . . . . . . . . . . . . . . .

Preface
Publication 17946.5.2 - May 1996
Using This Manual
This manual shows you how to use your FLEX I/O Analog modules
with Allen-Bradley programmable controllers. The manual helps you
install, program and troubleshoot your modules.
You must be able to program and operate an Allen-Bradley
programmable controller to make efficient use of your FLEX I/O
modules. In particular, you must know how to program block
transfers.
We assume that you know how to do this in this manual. If you do
not, refer to the appropriate programming and operations manual
before you attempt to program your modules.
In this manual, we refer to:
–the analog input or analog output module as the “input
module” or ‘‘output module”
–the Programmable Controller as the “controller”
This manual is divided into five chapters. The following chart lists
each chapter with its corresponding title and a brief overview of the
topics covered in that chapter.
Chapter Title Contents
1Overview of FLEX I/O and Analog
modules
Describes FLEX I/O Analog modules, features, and how
they function
2How to Install Your Analog
Module
How to install and wire the modules
3Module Programming Explains block transfer programming, sample programs
4Writing Configuration to and
Reading Status From with a
Remote I/O Adapter
Explains how to configure your modules and read status
information from your modules when using a remote I/O
adapter
5How Communication Takes Place
and I/O Image Table Mapping
with the DeviceNet Adapter
Explains how you communicate with your modules, and
how the I/O image is mapped when using a DeviceNet
adapter
Appendix Title Contents
ASpecifications Specifications for the analog modules
BDifferences Between Series A
and Series B Analog Modules
Lists major differences between series.
CData Formats Explains 2's complement and left justification of numbers
Purpose of this Manual
Audience
Vocabulary
Manual Organization

P–2 Using This Manual
Publication 17946.5.2 - May 1996
We use these conventions in this manual:
In this manual, we show: Like this:
that there is more information about a topic
in another chapter in this manual
that there is more information about the
topic in another manual More
For additional information on FLEX I/O systems and modules, refer
to the following documents:
Catalog
Publications
Catalog
Number Voltage Description Installation
Instructions
User
Manual
1794 1794 FLEX I/O Product Data 17942.1
1794ACN 24V dc ControlNet Adapter 17945.8
1794ADN 24V dc DeviceNet Adapter 17945.14 17946.5.5
1794ASB 24V dc Remote I/O Adapter 17945.11 17946.5.3
1794TB2
1794TB3
2wire Terminal Base
3wire Terminal Base 17945.2
1794TBN Terminal Base Unit 17945.16
1794TBNF Fused Terminal Base Unit 17945.17
1794TB3T Temperature Terminal Base Unit 17945.41
1794IB16 24V dc 16 Input Module 17945.4
1794OB16 24V dc 16 Output Module 17945.3
1794IB10XOB6 24V dc 10 Input/6 Output Module 17945.24
1794IE8 24V dc Selectable Analog 8 Input Module 17945.6
1794OE4 24V dc Selectable Analog 4 Output Module 17945.5 17946.5.2
1794IE4XOE2 24V dc 4 Input/2 Output Analog Module 17945.15
1794IR8 24V dc 8 RTD Input Analog Module 17945.22 17946.5.4
1794IT8 24V dc 8 Thermocouple Input Module 17945.21 17946.5.7
1794IB8S 24V dc Sensor Input Module 17945.7
1794IA8 120V ac 8 Input Module 17945.9
1794OA8 120V ac Output Module 17945.10
1794CE1 Extender Cable 17942.12
1794NM1 Mounting Kit 17942.13
1794PS1 24V dc Power Supply 17945.35
Conventions
For Additional Information

Chapter 1
Publication 17946.5.2 - May 1996
Overview of FLEX I/O and your
Analog Modules
In this chapter, we tell you about:
•what the FLEX I/O system is and what it contains
•types of FLEX I/O analog modules
•how FLEX I/O analog modules communicate with programmable
controllers
•the features of your analog modules
FLEX I/O is a small, modular I/O system for distributed
applications that performs all of the functions of rack-based I/O. The
FLEX I/O system contains the following components shown below:
Adapter Terminal Base
I/O Module
20125
IV IV IV IV
5
IVIV
•adapter/power supply – powers the internal logic for as many as
eight I/O modules
•terminal base – contains a terminal strip to terminate wiring for
two- or three-wire devices
•I/O module – contains the bus interface and circuitry needed to
perform specific functions related to your application
Chapter Objectives
The FLEX I/O System

1–2 Overview of FLEX I/O and your Analog Modules
Publication 17946.5.2 - May 1996
We describe the following FLEX I/O Analog modules in this user
manual:
Catalog Number Voltage Inputs Outputs Description
1794IE8 24V dc 8 - analog - 8 input, singleended, non-isolated
1794OE4 24V dc - 4 analog - 4 output, singleended, non-isolated
1794IE4XOE2 24V dc 4 2 analog - 4 input, singleended, non-isolated
and 2 output, singleended, nonisolated
FLEX I/O analog input, output and combination modules are block
transfer modules that interface analog signals with any
Allen-Bradley programmable controllers that have block transfer
capability. Block transfer programming moves input from the
module’s memory to a designated area in the processor data table,
and output data words from a designated area in the processor data
table to the module’s memory. Block transfer programming also
moves configuration words from the processor data table to module
memory.
The analog modules have selectable ranges as shown in the table
below:
Voltage Current
0 to 10V dc 0 to 20mA
+/-10V dc 4 to 20mA
The adapter/power supply 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 adapter obtain input values and status from the
module, and let you send output values and establish the module’s
mode of operation. Figure 1.1 describes the communication process.
Types of FLEX I/O Modules
How FLEX I/O Analog
Modules Communicate
with Programmable
Controllers

1–3 Overview of FLEX I/O and your Analog Modules
Publication 17946.5.2 - May 1996
Figure 1.1
An
Example of Communication Between an Adapter and an
Analog Input Module
ADAPTER
ACTIVE FAULT
LOCAL
FAULT
24VDC
POWER SUPPLY
RIO ADAPTER
1794ASB
AllenBradley
2
AllenBradley
INPUT 0 INPUT 2 INPUT 4 INPUT 6INPUT 1 INPUT 3 INPUT 5 INPUT 7
IV IV IV IV IV IV IV IV
ANALOG INPUT
1794-IE8
1
The adapter transfers your configuration data
to the module using a BTW.
Flexbus
External devices transmit
analog signals to the module.
2
The module converts analog signals
into binary format and stores these
values until the adapter requests their
transfer.
3
Your ladder program instructs the
adapter to perform a BTR of the values
and stores them in a data table.
4
The adapter and module determine
that the transfer was made without error
and input values are within specified
range.
5
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.
6
Your ladder program performs BTWs to the module when you power
it up, and any time you wish to reconfigure the module.
7

1–4 Overview of FLEX I/O and your Analog Modules
Publication 17946.5.2 - May 1996
Each module has a unique label identifying its keyswitch position,
wiring and module type. A removable label provides space for
writing individual designations per your application.
INPUT 0 INPUT 2 INPUT 4 INPUT 6INPUT 1 INPUT 3 INPUT 5 INPUT 7 PWR
IV IV IV IV IV IV IV IV
ANALOG INPUT
3
1794-IE8
AllenBradley
PWR
ANALOG OUTPUT
4
1794-OE4
AllenBradley
OUTPUT 0
IRET RETV
OUTPUT 1
IRET RETV
OUTPUT 2
IRET RETV
OUTPUT 3
IRET RETV
Removable
Label
Input Designators
Output Designators
Keyswitch
Position
Indicator (#3)
1794IE8
1794OE4
Keyswitch
Position
Indicator (#4)
Module Type
Module Type
INPUT 0 INPUT 2INPUT 1 INPUT 3 PWR
IV IV IV IV V
ANALOG COMBO
5
1794-IE4XOE2
AllenBradley
Removable
Label
Module Type
OUTPUT 0
IRET RETV
OUTPUT 1
IRET RETV
Keyswitch
Position
Indicator (#5)
Green Power
Indicator
Green Power
Indicator
Input and Output Designators
1794IE4XOE2
Green Power
Indicator
Removable
Label
In this chapter you learned about the FLEX I/O system and the types
of analog modules and how they communicate with programmable
controllers.
Features of your Analog
Modules
Chapter Summary

Chapter 2
Publication 17946.5.2 - May 1996
How to Install Your
Analog Module
In this chapter, we tell you about:
•how to install your module
•how to set the module keyswitch
•how to wire the terminal base
•the indicators
Before installing your analog module in the I/O chassis:
You need to: As described under:
Calculate the power requirements of all
modules in each chassis. Power Requirements, page 2-2
Position the keyswitch on the terminal base Installing the Module, page 2-4
!ATTENTION: +24V dc power must be applied to
your module before operation. If power is not applied,
the module position will appear to the adapter as an
empty slot in your chassis. If the adapter does not
recognize your module after installation is completed,
cycle power to the adapter.
If this product has the CE mark it is approved for installation within
the European Union and EEA regions. It has been designed and
tested to meet the following directives.
EMC Directive
This product is tested to meet Council Directive 89/336/EEC
Electromagnetic Compatibility (EMC) and the following standards,
in whole or in part, documented in a technical construction file:
•EN 50081-2EMC – Generic Emission Standard, Part 2 –
Industrial Environment
•EN 50082-2EMC – Generic Immunity Standard, Part 2 –
Industrial Environment
This product is intended for use in an industrial environment.
Chapter Objectives
Before You Install Your
Analog Module
Compliance to
European Union Directives

2–2 How to Install Your Analog Module
Publication 17946.5.2 - May 1996
Low Voltage Directive
This product is tested to meet Council Directive 73/23/EEC
Low Voltage, by applying the safety requirements of EN 61131–2
Programmable Controllers, Part 2 – Equipment Requirements and
Tests.
For specific information required by EN 61131-2, see the appropriate
sections in this publication, as well as the following Allen-Bradley
publications:
•Industrial Automation Wiring and Grounding Guidelines For
Noise Immunity, publication 1770-4.1
•Guidelines for Handling Lithium Batteries, publication AG-5.4
•Automation Systems Catalog, publication B111
The wiring of the terminal base unit is determined by the current
draw through the terminal base. Make certain that the current draw
does not exceed 10A.
!ATTENTION: Total current draw through the
terminal base unit is limited to 10A. Separate power
connections may be necessary.
Power Requirements

2–3 How to Install Your Analog Module
Publication 17946.5.2 - May 1996
Methods of wiring the terminal base units are shown in the
illustration below.
Wiring when total current draw is less than 10A
W iring when total current draw is greater than 10A
Daisychaining
Individual
T otal current draw through any base unit must not be greater than 10A
Combination
24V dc
24V dc
24V dc
24V dc
24V dc or
120V ac
24V dc
ATTENTION: Do not daisy chain power or
ground from an analog terminal base unit to any ac
or dc discrete module terminal base unit.
!
Note: Use this configuration if using any
noisy" dc discrete I/O modules in your system.
Analog module wiring separate from discrete wiring.
Analog Module
Note: All modules powered by the same power supply
must be analog modules for this configuration.
Note: All modules must be analog modules for this configuration.
Analog Module
Discrete
Module
Discrete
Module
Discrete
Module
Discrete
Module
Analog Module Analog Module Analog Module
Analog Module Analog Module Analog Module

2–4 How to Install Your Analog Module
Publication 17946.5.2 - May 1996
Installation of the analog module consists of:
•mounting the terminal base unit
•installing the analog module into the terminal base unit
•installing the connecting wiring to the terminal base unit
If you are installing your module into a terminal base unit that is
already installed, proceed to “Mounting the Analog Module on the
Terminal Base” on page 2–7.
Mounting the Terminal Base Unit on a DIN Rail
!ATTENTION: Do not remove or replace a terminal
base unit when power is applied. Interruption of the
flexbus can result in unintended operation or machine
motion.
1.Remove the cover plug (if used) in the male connector of the unit
to which you are connecting this terminal base unit.
2.Check to make sure that the 16 pins in the male connector on the
adjacent device are straight and in line so that the mating female
connector on this terminal base unit will mate correctly.
3.Position the terminal base on the 35 x 7.5mm DIN rail A(A-B pt.
no. 199-DR1; 46277-3; EN 50022) at a slight angle with hook B
on the left side of the terminal base hooked into the right side of
the unit on the left.
A
C
D
BA
D
4.Make certain that the female flexbus connector C is fully
retracted into the base unit.
Installing the Module

2–5 How to Install Your Analog Module
Publication 17946.5.2 - May 1996
5.Rotate the terminal base onto the DIN rail with the top of the rail
hooked under the lip on the rear of the terminal base. Use caution
to make sure that the female flexbus connector does not strike
any of the pins in the mating male connector.
6.Press the terminal base down onto the DIN rail until flush. The
locking tab D will snap into position and lock the terminal base to
the DIN rail.
7.If the terminal base does not lock in place, use a screwdriver or
similar device to move the locking tab down, press the terminal
base flush with the DIN rail and release the locking tab to lock
the base in place.
8.Gently push the female flexbus connector Cinto the adjacent
terminal base or adapter female connector to complete the flexbus
connections.
9.Repeat the above steps to install the next terminal base.
Panel/Wall Mounting
Installation on a wall or panel consists of:
•laying out the drilling points on the wall or panel
•drilling the pilot holes for the mounting screws
•mounting the adapter mounting plate
•installing the terminal base units and securing them to the wall or
panel
If you are installing your module into a terminal base unit that is
already installed, proceed to “Mounting the Analog Module on the
Terminal Base” on page 2–7.
Use the mounting kit Cat. No. 1794-NM1 for panel/wall mounting.
1.4
(35.5)
1
1794NM1 Mounting Kit
Contents:
1 - Mounting Plate for Adapter
2 - 18 #6 selftapping screws
(2 for the adapter, and 2
each for up to 8 modules)
2
Adapter Module
(not included)
Terminal Base Unit
(not included)

2–6 How to Install Your Analog Module
Publication 17946.5.2 - May 1996
To install the mounting plate on a wall or panel:
1. Lay out the required points on the wall/panel as shown in the
drilling dimension drawing.
1.4
(35.5)
.83 (21)
2.3
(58.5)
2.3
(58.5)
1.4
(35.5)
1.4
(35.5)
Inches
(Millimeters)
Drilling Dimensions for Panel/Wall Mounting of FLEX I/O
2. Drill the necessary holes for the #6 self-tapping mounting screws.
3. Mount the mounting plate (1) for the adapter module using two
#6 self-tapping screws (18 included for mounting up to 8 modules
and the adapter).
Important: Make certain that the mounting plate is properly
grounded to the panel. Refer to “Industrial Automation
Wiring and Grounding Guidelines,” publication
1770-4.1.
4. Hold the adapter (2) at a slight angle and engage the top of the
mounting plate in the indention on the rear of the adapter module.
5. Press the adapter down flush with the panel until the locking lever
locks.
6. Position the terminal base unit up against the adapter and push the
female bus connector into the adapter.
7. Secure to the wall with two #6 self-tapping screws.
8. Repeat for each remaining terminal base unit.
Note: The adapter is capable of addressing eight modules. Do not
exceed a maximum of eight terminal base units in your system.
More

2–7 How to Install Your Analog Module
Publication 17946.5.2 - May 1996
Mounting the Analog Module on the Terminal Base Unit
1. Rotate the keyswitch (1) on the terminal base unit (2) clockwise
to the position required for the specific type of analog module.
4
1
3
2
5
6
7
Analog Module Cat. No. Keyswitch Position
1794IE8 3
1794OE4 4
1794IE4XOE2 5
2. Make certain the flexbus connector (3) is pushed all the way to
the left to connect with the neighboring terminal base/adapter.
You cannot install the module unless the connector is fully
extended.
3. Make sure that the pins on the bottom of the module are straight
so they will align properly with the connector in the terminal base
unit.
4. Position the module (4) with its alignment bar (5) aligned with
the groove (6) on the terminal base.
5. Press firmly and evenly to seat the module in the terminal base
unit. The module is seated when the latching mechanism (7) is
locked into the module.
6. Repeat the above steps to install the next module in its terminal
base unit.