Rockwell Automation 1794-IRT8XT User Manual
FLEX I/O Thermocouple, RTD, and Millivolt
Input Modules
Catalog Numbers 1794-IRT8, 1794-IRT8K, 1794-IRT8XT
User Manual
Important User Information
WARNING
IMPORTANT
ATTENTION
SHOCK HAZARD
BURN HAZARD
Solid state equipment has operational characteristics differing from those of electromechanical equipment. Safety Guidelines for the Application,
Installation and Maintenance of Solid State Controls (publication SGI-1.1
http://literature.rockwellautomation.com
) describes some important differences between solid state equipment and hard-wired electromechanical
devices. Because of this difference, and also because of the wide variety of uses for solid state equipment, all persons responsible for applying this
equipment must satisfy themselves that each intended application of this equipment is acceptable.
In no event will Rockwell Automation, Inc. be responsible or liable for indirect or consequential damages resulting from the use or application of this
equipment.
The examples and diagrams in this manual are included solely for illustrative purposes. Because of the many variables and requirements associated
with any particular installation, Rockwell Automation, Inc. cannot assume responsibility or liability for actual use based on the examples and
diagrams.
No patent liability is assumed by Rockwell Automation, Inc. with respect to use of information, circuits, equipment, or software described in this
manual.
Reproduction of the contents of this manual, in whole or in part, without written permission of Rockwell Automation, Inc., is prohibited.
Throughout this manual, when necessary, we use notes to make you aware of safety considerations.
available from your local Rockwell Automation sales office or online at
Identifies information about practices or circumstances that can cause an explosion in a hazardous environment, which may
lead to personal injury or death, property damage, or economic loss.
Identifies information that is critical for successful application and understanding of the product.
Identifies information about practices or circumstances that can lead to: personal injury or death, property damage, or
economic loss. Attentions help you identify a hazard, avoid a hazard, and recognize the consequence.
Labels may be on or inside the equipment, such as a drive or motor, to alert people that dangerous voltage may be present.
Labels may be on or inside the equipment, such as a drive or motor, to alert people that surfaces may reach dangerous
temperatures.
Allen-Bradley, Rockwell Automation, FLEX I/O, RSLinx, RSLogix 5000 and TechConnec t are trademarks of Rockwell Automation, Inc.
Trademarks not belonging to Rockwell Automation are property of their respective companies.
Summary of Changes
This manual contains new and updated information. Changes throughout this
revision are marked by change bars, as shown to the right of this paragraph.
New and Updated Information
This table contains the changes made to this revision.
Changes Page
Addition of two catalogs – 1794-IRT8K and 1794-IRT8XT 1, 53
The following sections have been added to Chapter 1 – Overview of FLEX I/O
and Your Thermocouple, RTD, and Millivolt Input Module:
1
•The FLEX System
•Types of Modules
•What the FLEX I/O Input Module Does
•The FLEX I/O Module in a Logix Control System
The following section has been added to Chapter 2 – Install Your FLEX I/O Input
Module:
8
•Series A and Series B
The following new topics have been added:
•Configure Your FLEX I/O Module with RSLogix 5000 Software
21
(Chapter 3)
•Troubleshoot the Module (Chapter 6)
•Electronic Data Sheet (EDS) Files (Appendix B)
51
57
The following topic, previously Chapter 3 in the last revision, has been
relegated to the Appendices section:
•Program Your Thermocouple/RTD Input Module (Appendix C)
59
Additional less significant changes (such as improvement of drawings) have
been made throughout the document.
iii Publication 1794-6.5.12 - September 2011
iv Summary of Changes
Notes:
Publication 1794-6.5.12 - September 2011
Overview of FLEX I/O and Your
Thermocouple, RTD, and
Millivolt Input Module
Table of Contents
Summary of Changes
New and Updated Information. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . iii
Preface
Who Should Use This Manual. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ix
Purpose of the Manual. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ix
About the Vocabulary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ix
Related Documentation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . x
Common Techniques Used in this Manual. . . . . . . . . . . . . . . . . . . . . . xii
Chapter 1
Overview. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
The FLEX System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
Types of Modules. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
What the FLEX I/O Input Module Does . . . . . . . . . . . . . . . . . . . . . . . 2
The FLEX I/O Module in a Logix Control System . . . . . . . . . . . . . . . 3
Physical Features of Your Module . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
Chapter Summary. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Install Your FLEX I/O Input
Module
Configure Your FLEX I/O
Module with RSLogix 5000
Software
Read and Write Configuration
Maps for the FLEX I/O Module
Chapter 2
Overview. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Before You Install Your Module . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Series A and Series B . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Power Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Install the Module . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Mount on a DIN Rail . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Mount on a Panel or Wall . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Mount the FLEX I/O Module on the Terminal Base Unit . . . . . 14
Wiring Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
Connect Wiring to the FLEX I/O Module . . . . . . . . . . . . . . . . . . 16
Identify RTD Wire Pairs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
Chapter Summary. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
Chapter 3
Overview. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
Add and Configure the FLEX I/O Module. . . . . . . . . . . . . . . . . . . . . 21
Chapter Summary. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
Chapter 4
Overview. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
Configure Your Input Module . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
Configurable Options and Their Effect on the Channels . . . . . . . . . . 27
Options that Affect All Channels . . . . . . . . . . . . . . . . . . . . . . . . . . 27
Options that Affect Each Group of Four Inputs . . . . . . . . . . . . . 28
Sensor Types. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
Read Data From the Module. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
v Publication 1794-6.5.12-EN-E - September 2011
vi Table of Contents
Map Data for the Module . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
Thermocouple and RTD Input Module Image Table
Mapping . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
Block Transfer Read and Write . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
Bit/Word Descriptions for the Input Module Block Transfer
Read Words . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
Using Series A Functionality in a
Series B Module . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38
Chapter Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38
Chapter 5
Calibrate Your Module Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39
When and How to Calibrate Your FLEX I/O Module. . . . . . . . . . . . 39
Tools and Equipment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
Calibrate Your Input Module. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
Calibration Setup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41
Wiring Connections for Calibrating the Thermocouple and
RTD Input Module . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41
Read and Write Words for Calibration. . . . . . . . . . . . . . . . . . . . . . 42
EDT Calibration Command and Command Data Summary . . . . 44
Offset Calibration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45
Gain Calibration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46
Current Source Calibration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47
Cold Junction Calibration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49
Channel Loop Compensation Calibration . . . . . . . . . . . . . . . . . . . 49
Chapter Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49
Chapter 6
Troubleshoot the Module Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51
Module Indicators . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51
Chapter Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52
Appendix A
Specifications Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53
General Specifications. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53
Environmental Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55
Certifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56
Appendix B
Electronic Data Sheet (EDS)
Files
Publication 1794-6.5.12-EN-E - September 2011
Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57
Updating EDS File . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57
EDS Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58
Table of Contents vii
Appendix C
Programming Your Module
with PLC Family Processors
Overview. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59
Enter Block Transfer Instructions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59
PLC-2 Family Processor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60
PLC-3 Family Processor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60
PLC-5 Family Processor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61
PLC-5/250 Family Processor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62
Appendix D
Safety Approvals European Hazardous Location Approval. . . . . . . . . . . . . . . . . . . . . . . 65
North American Hazardous Location Approval . . . . . . . . . . . . . . . . . 66
Index
Publication 1794-6.5.12-EN-E - September 2011
viii Table of Contents
Notes:
Publication 1794-6.5.12-EN-E - September 2011
Preface
Read this preface to familiarize yourself with the rest of the manual. It provides
information concerning:
• who should use this manual
• the purpose of this manual
• related documentation
• conventions used in this manual
• terminology used in this manual
Who Should Use This Manual
Purpose of the Manual
We assume that you have previously used an Allen-Bradley programmable
controller, that you are familiar with its features, and that you are familiar with
the terminology we use. If not, read the user manual for your processor before
reading this manual.
This manual is a reference guide for the FLEX I/O Thermocouple, RTD,
Millivolt Input Modules. It describes the procedures for installing, configuring
and troubleshooting your module. For more information, consult the
following chapters.
Topic See
Overview of FLEX I/O and Your Thermocouple, RTD, and Millivolt Input Module Chapter 1
Install Your FLEX I/O Input Module Chapter 2
Configure Your FLEX I/O Module with RSLogix 5000 Software Chapter 3
Read and Write Configuration Maps for the FLEX I/O Module Chapter 4
Calibrate Your Module Chapter 5
Troubleshoot the Module Chapter 6
Specifications Appendix A
Electronic Data Sheet (EDS) Files Appendix B
Programming Your Module with PLC Family Processors Appendix C
Safety Approvals A
ppendix D
About the Vocabulary
ix Publication 1794-6.5.12 - September 2011
This manual covers the 1794-IRT8, 1794-IRT8K, and 1794-IRT8XT modules,
which are identical, except that the 1794-IRT8K is conformally coated.
In this manual, we refer to:
• the individual Thermocouple, RTD, and mV module as the “module,”
or “TC, RTD, and mV module.”
• the programmable controller as the “controller” or the “processor.”
x Preface
Related Documentation
The following documents contain additional information about Rockwell
Automation products. To obtain a copy, contact your local
Rockwell Automation office or distributor.
Resource Description
FLEX I/O Product Profile, publication 1794-PP019
FLEX I/O ControlNet Redundant Media Adapter,
publication 1794-5.18
FLEX I/O EtherNet/IP Adapter Module Installation
Instructions, publication 1794-IN082
FLEX I/O ControlNet Adapter Module Installation
Instructions, publication 1794-IN128
FLEX I/O DeviceNet Adapter Module Installation
Instructions, publication 1794-IN099
Remote I/O Adapter Modules Installation Instructions,
publication 1794-IN098
Remote I/O Adapter Module User Manual, publication
1794-UM009
FLEX I/O PROFIBUS Adapter Module Installation
Instructions, publication 1794-IN087
FLEX I/O PROFIBUS Adapter Module User Manual,
publication 1794-UM057
Flex I/O Digital Input Modules Installation Instructions,
publication 1794-IN093
Flex I/O Digital DC Sourcing Input and Sinking Output
Modules Installation Instructions,
publication 1794-IN095
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x xxxx
x xxxx
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x xxxxxxxxxxxxx
x xxxxxxxxxxxxx
x xxxxxxxxxxxxx
xxxxx Comprehensive product profile for the FLEX I/O product line.
Information on how to install the FLEX I/O ControlNet Redundant Media
Adapter (1794-ACNR).
Information on how to install the FLEX I/O EtherNet/IP Adapter Module
(Catalog No. 1794-AENT).
Information on how to install the ControlNet Adapter Modules
(Catalog No. 1794-ACN15, 1794-ACN15K, 1794-ACNR15, 1794-ACNR15XT,
Series D).
Information on how to install the FLEX I/O DeviceNet Adapter Modules
(Catalog No. 1794-ADN, 1794-ADNK).
Information on how to install the Remote I/O Adapter Modules
(Catalog No. 1794-ASB, 1794-ASB2, 1794-ASBK, 1794-ASB2K).
Information on how to use the Remote I/O Adapter Module
(Catalog No. 1794-ASB).
Information on how to install the FLEX I/O PROFIBUS Adapter
(Catalog No. 1794-APB).
Information on how to use the FLEX I/O PROFIBUS Adapter Module
(Catalog No. 1794-APB).
Information on how to install the Flex I/O Digital Input Modules
(Catalog No. 1794-IB8, 1794-IB16, 1794-IB16K, 1794-IB32).
Information on how to install the Flex I/O Digital DC Sourcing Input and
Sinking Output Modules (Catalog No. 1794-IV16, 1794-OV16, 1794-OV16P).
Flex I/O Digital DC Sourcing Output Modules Installation
Instructions, publication 1794-IN094
Flex I/O Input/ Output Module Installation Instructions,
publication 1794-IN083
Flex I/O 8 Output Relay Module Installation Instructions,
publication 1794-IN019
FLEX I/O Input, Output and Input/Output Analog Modules
Installation Instructions, publication 1794-IN100
FLEX I/O Analog Module User Manual,
publication 1794-6.5.2
FLEX I/O Isolated Analog Output Module Installation
Instructions, publication 1794-IN037
Publication 1794-6.5.12 - September 2011
x xxxxxxxxxxxxx
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xxxxxxx
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Information on how to install the Flex I/O Digital DC Sourcing Output Modules
(Catalog No. 1794-OB8, 1794-OB8EP, 1794-OB16, 1794-OB16P, 1794-OB32P).
Information on how to install the Flex I/O Input/ Output Modules
(Catalog No. 1794-IB16XOB16P, 1794-IB10XOB6).
Information on how to install the Flex I/O 8 Output Relay Modules
(Catalog No. 1794-OW8, 1794-OW8K, 1794-OW8XT).
Information on how to install the FLEX I/O Input, Output and Input/Output
Analog Modules (Catalog No. 1794-IE8, 1794-IE4XOE2, 1794-OE4, 1794-IE8K,
1794-OE4K).
Information on how to install the FLEX I/O Analog Modules
(Catalog No. 794-OE4, 1794-IE8, 1794-IE12, 1794-OE12, 1794-IE4XOE2,
1794-IE8XOE4, 1794-IE4XOE2XT, 1794-IE8XT, 1794-OE4XT).
Information on how to install the FLEX I/O Isolated Analog Output Module
(Catalog No. 1794-OF4I).
Resource Description
Preface xi
FLEX I/O 4 Isolated Input Module Installation Instructions,
publication 1794-IN038
x xxxxxxxxxxxxx
FLEX I/O 2 In/2 Out Isolated Analog Combo Module
Installation Instructions, publication 1794-IN039
x
xxxxxxxxxxxxx
FLEX I/O Isolated Analog Modules User Manual,
publication 1794-6.5.8
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FLEX I/O 8 Thermocouple Input Module Installation
Instructions, publication 1794-IN021
x xxxxxxxxxxxxx
FLEX I/O 8 Input RTD Module User Manual,
publication 1794-6.5.4
x xxxxxxxxxxxxx
FLEX I/O Thermocouple/Millivolt Input Module User
Manual, publication 1794-6.5.7
x xxxxxxxxxxxxx
FLEX I/O Thermocouple/RTD Input Analog Module
Instructions, publication 1794-IN050
x xxxxxxxxxxxxx
2-Input Frequency Module Installation Instructions,
publication 1794-IN049
x xxxxxxxxxxxxx
FLEX I/O Frequency Input Module User Manual,
publication 1794-6.5.11
x xxxxxxxxxxxxx
24V FLEX I/O 2 Channel Incremental Encoder Module
Installation Instructions, publication 1794-IN063
x
xxxxxxxxxxxxx
Information on how to install the FLEX I/O 4 Isolated Input Module
(Catalog No. 1794-IF4I).
Information on how to install the FLEX I/O 2 In/2 Out Isolated Analog Combo
Module (Catalog No. 1794-IF2XOF2I).
Information on how to use the FLEX I/O Isolated Analog Modules
(Catalog No. 1794-IF4I, 1794-OF4I, 1794-IF2XOF2I, 1794-IF4IXT, 1794-IF4ICFXT,
1794-OF4IXT, 1794-IF2XOF2IXT).
Information on how to install the FLEX I/O 8 Thermocouple Input Modules
(Catalog No. 1794-IT8, 1794-IR8).
Information on how to use the FLEX I/O 8 Input RTD Module
(Catalog No. 1794-IR8).
Information on how to use the Thermocouple and Millivolt Input Module
(Catalog No. 1794-IT8).
Information on how to install the Thermocouple/Millivolt Input Modules
(Catalog No. 1794-IRT8, 1794-IRT8K, 1794-IRT8XT).
Information on how to install the 2-Input Frequency Module
(Catalog No. 1794-IJ2, 1794-IJ2K, 1794-IJ2XT).
Information on how to use the FLEX I/O Frequency Input Module
(Catalog No. 1794-IJ2).
Information on how to install the 24V FLEX I/O 2 Channel Incremental Encoder
Module (Catalog No. 1794-ID2).
FLEX Integra Analog Module User Manual,
publication 1793-6.5.1
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FLEX I/O 4 Channel Pulse Counter Module Installation
Instructions, publication 1794-IN064
x xxxxxxxxxxxxx
FLEX I/O Very High Speed Counter Module Installation
Instruction, publication 1794-IN067
x xxxxxxxxxxxxx
FLEX I/O 48V DC Input and Output Modules Installation
Instructions, publication 1794-IN105
x xxxxxxxxxxxxx
FLEX I/O AC Digital Input Modules Installation
Instructions, publication 1794-IN102
x xxxxxxxxxxxxx
FLEX I/O Digital AC Output Modules Installation
Instructions, publication 1794-IN103
x xxxxxxxxxxxxx
FLEX I/O 220V AC Input and Output Modules Installation
Instructions, publication 1794-IN104
x xxxxxxxxxxxxx
FLEX I/O Terminal Base Units Installation Instructions,
publication 1794-IN092
x xxxxxxxxxxxxx
Interconnect Cable Installation Instructions,
publication 1794-5.12
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Information on how to install the FLEX Integra Analog Module (Catalog No.
1793-IE2X0E1,1793-IE2XOE1S, 1793-IE4, 1793-IE4S, 1793-OE2, 1793-OE2S).
Information on how to install the 24V DC FLEX I/O 4-Channel Module
(Catalog No. 1794-IP4).
Information on how to install the Very High Speed Counter Module
(Catalog No. 1794-VHSC).
Information on how to install the FLEX I/O 48V DC Input and Output Modules
(Catalog No. 1794-IC16, 1794-OC16).
Information on how to install the FLEX I/O AC Input Modules
(Catalog No. 1794-IA8, 1794-IA8I, 1794-IA16).
Information on how to install the FLEX I/O Digital AC Output Modules
(Catalog No. 1794-OA8, 1794-OA8K, 1794-OA8I, 1794-OA16).
Information on how to install the FLEX I/O 220V AC Input and Output Modules
(Catalog No. 1794-IM8, 1794-OM8).
Information on how to install the FLEX I/O Terminal Base Units
(Catalog No. 1794-TB2, 1794-TB3, 1794-TB3K, 1794-TB3S, 1794-TB32,
1794-TB3G, 1794-TB3GK, 1794-TB3GS, 1794-TB3T, 1794-TB3TS, 1794-TBN,
1794-TBNK, 1794-TBNF).
Information on how to install the Interconnect Cable
(Catalog No. 1794-CE1, 1794-CE3).
Publication 1794-6.5.12 - September 2011
xii Preface
Resource Description
FLEX I/O DC Power Supply Installation Instructions,
publication 1794-IN069
Industrial Automation Wiring and Grounding Guidelines,
publication 1770-4.1
Rockwell Automation Industrial Automation Glossary,
AG-7.1
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Common Techniques Used in this Manual
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The following conventions are used throughout this manual:
• Bulleted lists such as this one provide information, not procedural steps.
• Numbered lists provide sequential steps or hierarchical information.
• Italic type is used for emphasis.
Information on how to install the FLEX I/O DC Power Supply
(Catalog No. 1794-PS13, 1794-PS3).
In-depth information on grounding and wiring Allen-Bradley programmable
controllers.
A glossary of industrial automation terms and abbreviations.
Publication 1794-6.5.12 - September 2011
Chapter
I/O moduleTerminal baseAdapter
1794-IRT8
2
+
2
+
45374
1
Overview of FLEX I/O and Your Thermocouple,
RTD, and Millivolt Input Module
Overview
The FLEX System
This chapter provides a description of the FLEX I/O Thermocouple, RTD,
and Millivolt Input module and an overview of how it communicates with
programmable controllers.
Topic Page
The FLEX System 1
Types of Modules 2
What the FLEX I/O Input Module Does 2
The FLEX I/O Module in a Logix Control System 3
Physical Features of Your Module 4
Chapter Summary 5
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 system contains
the following components shown below:
• Adapter – transfers read and write configuration data to and from the
I/O module
• 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
1 Publication 1794-6.5.12 - September 2011
2 Overview of FLEX I/O and Your Thermocouple, RTD, and Millivolt Input Module
The FLEX system consists of an adapter module, terminal base unit, DIN rail,
power supply, and adapter cabling components. You can use up to 8 terminal
bases per adapter module.
For detailed instructions on how to set up and install your module, refer to the
topic, Install Your FLEX I/O Input Module, on page 7.
Types of Modules
What the FLEX I/O Input Module Does
The module refer to the following catalogs.
Catalog No. Voltage Inputs Description
1794-IRT8 24V DC 8 Analog – 8-pt, 16 bit non-isolated RTD,
thermocouple and mV Input module
1794-IRT8K 24V DC 8 Analog – 8-pt, 16 bit non-isolated RTD,
thermocouple and mV Input module.
Conformally coated module.
1794-IRT8XT 24V DC 8 Analog – 8-pt, 16 bit non-isolated RTD,
thermocouple and mV Input module designed
for extended temperature.
The module accepts up to 8 thermocouple or RTD inputs. The inputs are
nonisolated and are selected with analog multiplexers. The inputs accept
millivolt or resistive inputs. Default input spans are -40.00 mV… +100.00 mV
or 0.0…500.0 Ω. Fault indicators are located on the field side.
No switches or jumpers are used on the TC and RTD Input module. The
inputs have both fixed hardware filters and selectable firmware digital filters.
The module is a high-speed, high-accuracy temperature and millivolt
measuring module that accepts thermocouple inputs, 2-, 3-, and 4-wire RTD
inputs, and mV source inputs.
Publication 1794-6.5.12 - September 2011
It offers the following:
• wire-off, over-range, and under-range detection
• good common mode rejection
• usage with long thermocouple wiring
• usage with grounded or ungrounded thermocouples
The Series B version of 1794-IRT8 provides capability to work with grounded
thermocouples.
Use cold junction compensators (cat. no. 1794-CJC2) in thermocouple mode.
Two cold junction compensators are shipped with the 1794-IRT8.
Overview of FLEX I/O and Your Thermocouple, RTD, and Millivolt Input Module 3
IN 0 IN 2 IN 4 IN 6IN 1 IN 3 IN 5 IN 7
TC RTD INPUT 8 CHANNEL
3
1794-IRT8
PWR
FF F FF F F F
45316
The adapter transfers your configuration data.
FlexBus
External devices transmit
analog signals to the
module.
The module converts
analog signals into binary
format and stores these
values until the adapter
requests their transfer.
The adapter receives data
from the modules and stores
it in the data table.
The adapter module determines that the
transfer was made without error and
input values are within specified range.
Your ladder program can use and/or
move the data (if valid) before it is
overwritten by the transfer of new data
in a subsequent transfer.
1
4
5
6
2
3
New configuration data can be sent to
the module any time during operation.
7
1794-ACN15
1794-ACNR15
1794-ACNR15K
1794-ADN
1794-AENT
1794-APBDPV1
1794-ASB
1794-APB
Adapter
1794-AENT shown
The FLEX I/O Module in a Logix Control System
The FLEX I/O Thermocouple, RTD, and Millivolt modules are intelligent
modules that interface analog signals with Rockwell Automation
programmable controllers through a FLEX I/O adapter module.
The adapter transfers data to and from the module. These transfers allow:
• the adapter to obtain input or output values and status from the module
• the user to establish the mode of operation through a process called
configuration
The following illustration shows the flow of communication between the
adapter and the I/O module.
Typical Communication Between the Adapter and a Module
Publication 1794-6.5.12 - September 2011
4 Overview of FLEX I/O and Your Thermocouple, RTD, and Millivolt Input Module
45567
ATTENTION
A broader view of how the FLEX I/O module interfaces with the different
elements in a Logix system is shown in the sample illustration below.
PC running
controller and
Rockwell Automation
configuration software
Bridge
Ethernet
In this example, the FLEX I/O module communicates with the controller
through the adapter. The controller can produce and consume tags. It can
initiate MSG instructions that send and receive data or configure devices.
Configuration of devices and the network is done through the personal
computer running the controller and configuration software.
PanelView Station
FLEX System
1794 adapter
1794 FLEX I/O module
Physical Features of Your Module
To learn the prerequisites and steps to configure your FLEX I/O module
using RSLogix 5000 software, see Configure Your FLEX I/O Module with
RSLogix 5000 Software on page 21.
.
The following publications provide more information about
EtherNet/IP, and ControlNet modules in a Logix5000 system:
•EtherNet/IP Modules in Logix5000 Control Systems,
publication ENET-UM001
•ControlNet Modules in Logix5000 Control Systems,
publication CNET-UM001
The module label identifies the keyswitch position, wiring and module type. A
removable label provides space for writing individual designations per your
application. Indicators are provided to identify input fault conditions, and to
show when power is applied to the module.
Publication 1794-6.5.12 - September 2011
Overview of FLEX I/O and Your Thermocouple, RTD, and Millivolt Input Module 5
IN 0 IN 2 IN 4 IN 6IN 1 IN 3 IN 5 IN 7
TC RTD INPUT 8 CHANNEL
3
1794-IRT8
PWR
FF F FF F F F
1794-IRT8
Input designators
Module type
Removable label
Keyswitch
position indicator (#3)
Power on indicator
45317
Module Label and Indicators
Chapter Summary
In this chapter, you were introduced to the FLEX I/O system and the
Thermocouple, RTD, and mV input module, and how it communicates with
programmable controllers.
Publication 1794-6.5.12 - September 2011
6 Overview of FLEX I/O and Your Thermocouple, RTD, and Millivolt Input Module
Notes:
Publication 1794-6.5.12 - September 2011
Install Your FLEX I/O Input Module
ATTENTION
ATTENTION
Chapter
2
Overview
Before You Install Your Module
This chapter provides you with pre-installation requirements and instructions
on how to install your FLEX I/O Thermocouple, RTD, and Millivolt Input
module.
Topic Page
Before You Install Your Module 7
Series A and Series B 8
Power Requirements 8
Install the Module 10
Mount on a DIN Rail 10
Mount on a Panel or Wall 13
Mount the FLEX I/O Module on the Terminal Base Unit 14
Wiring Information 16
Chapter Summary 20
Before installing your FLEX I/O Thermocouple, RTD, and mV module, you
need to:
• verify that a suitable enclosure is available for installation of the module,
and
• position the keyswitch on the terminal base.
These modules do not receive primary operational power from the
backplane. 24V DC power must be applied to your module before
installation. If power is not applied, the module position may appear
to the adapter as an empty slot in your chassis.
If using a Series B product to replace a Series A product, connect a
wire between terminals 39 and 48 on the 1794-TB3G or 1794-TB3GS
terminal base unit. If not connected, the Series B product defaults to
Series B functionality.
7 Publication 1794-6.5.12 - September 2011
8 Install Your FLEX I/O Input Module
ATTENTION
ATTENTION
ATTENTION
Series A and Series B
The table, Series A and Series B Differences, describes the differences between
Series A and Series B of the FLEX I/O Thermocouple, RTD, and mV Input
modules.
Series A and Series B Differences
Mode 1794-IRT8 Series A 1794-IRT8, 1794-IRT8XT
Series B
Isolation Between user side and
system side
Common Mode Range +
Thermocouple Mode
Wire-off Detection
In the RSLogix 5000 software, if using a series B product to replace a
series A product, the module will be accepted without an electronic
key mismatch warning.
This is true for 1794-IRT8 and 1794-IRT8XT modules installed on
Ethernet/IP, ControlNet, or Remote I/O networks.
The CJC Status bit, Read Word 9, Bit 3 is added with the Firmware C
release of the 1794-IRT8 Series B module.
The CJC Status bit is turned On when the temperature between the
CJCs is greater than 6 °C but less than 12 °C.
When this temperature difference is above 12 °C, then the CJC Alarm
bits are set.
Also, if a CJC temperrature is over-range or under-range, then the
associated CJC Alarm bit is set. In this condition, the CJC Status bit is
not set.
The CJC Status bit did not exist in Series A.
4V DC +15V DC
When an open sensor is
detected, data defaults to
maximum value
Between user 24V DC and
user I/O; between user side
and system side
When open sensor is
detected, data defaults to
minimum value
Power Requirements
Publication 1794-6.5.12 - September 2011
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 10 A.
Total current draw through the terminal base unit is limited to 10 A.
Separate power connections may be necessary.
Install Your FLEX I/O Input Module 9
ATTENTION
Digital Input
Module
Analog
Module
Analog
Module
Analog
Module
Digital Output
Module
Digital Input
Module
TC/RTD/mV
Module
Analog
Module
TC/RTD/mV
Module
TC/RTD/mV
Module
TC/RTD/mV
Module
TC/RTD/mV
Module
Daisychain
Individual
Combination
24V DC
24V DC
24V DC
24V DC
24V DC
24V DC
45318
Wiring when total current draw is less than 10 A
Wiring when total current draw is less than 10 A
Thermocouple, RTD, Millivolt wiring separate from digital wiring.
Total current draw through any base unit must not be greater than 10 A
Do not daisychain power or ground from the terminal base unit to any
AC or DC digital module terminal base unit.
Methods of wiring the terminal base units are shown in the illustration below.
Publication 1794-6.5.12 - September 2011
10 Install Your FLEX I/O Input Module
ATTENTION
ATTENTION
Note the following considerations for each type of wiring
configuration:
• Daisychain – AIl modules must be analog or TC, RTD, and mV
modules for this configuration.
• Individual – Use this type of of configuration for any "noisy" DC
digital I/O modules in your system.
• Combination – All modules powered by the same power supply
must be analog or TC, RTD, and mV modules for the combination
type of configuration.
Install the Module
Installation of the FLEX I/O module consists of:
• mounting the terminal base unit
• installing the TC, RTD, and mV 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 the section, Mount the FLEX I/O Module on the
Terminal Base Unit, on page 14.
Mount on a DIN Rail
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.
Install the Terminal Base Unit
1. Remove the cover plug in the male connector of the unit to which you
are connecting this terminal base unit.
Publication 1794-6.5.12 - September 2011
Install Your FLEX I/O Input Module 11
1
2
3
4
6
7
7
8
9
0
2
+
2
+
45319
2
+
2
+
45320
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.
Make certain that the female FlexBus connector is fully retracted into
the base unit.
3. Position the terminal base at a slight angle and hooked over the top of
the 35 x 7.5 mm DIN rail A (Allen-Bradley part number 199-DR1;
46277-3).
4. Slide the terminal base over tight against the adapter, or proceeding
terminal base. Make sure the hook on the terminal base slides under the
edge of the adapter, or proceeding terminal base, and the FlexBus
connector is fully retracted.
Publication 1794-6.5.12 - September 2011
12 Install Your FLEX I/O Input Module
2
+
2
+
45321
2
+
2
+
45322
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 down on the terminal base unit to lock the terminal base on the
DIN rail. If the terminal base does not lock into place, use a screwdriver
or similar device to open the locking tab, press down on the terminal
base until flush with the DIN rail and release the locking tab to lock the
base in place.
Gently push the FlexBus connector into the side of the adapter, or
proceeding terminal base, to complete the backplane connection.
For specific wiring information, refer to the installation instructions for
the module you are installing in this terminal base unit.
7. Repeat the above steps to install the next terminal base unit.
Ensure that the cover of the FlexBus connector on the last terminal
base unit is in place.
Publication 1794-6.5.12 - September 2011
Install Your FLEX I/O Input Module 13
1
2
3
4
45323
Millimeters
(Inches)
Mount on a Panel or Wall
Installation of a FLEX system 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 the section, Mount the FLEX I/O Module on the
Terminal Base Unit, on page 14.
Use the mounting kit Cat. No. 1794-NM1 for panel or wall mounting.
35.5
(1.4)
0
9
1
8
7
6
2
2
+
+
7
2
3
4
Description Description
1 Mounting plate for adapter 3 Terminal base unit (not included)
2 #6 Self-tapping screws 4 Adapter module (not included)
To install the mounting plate on a wall or panel:
Publication 1794-6.5.12 - September 2011
14 Install Your FLEX I/O Input Module
Drilling Dimensions for Panel or Wall Mounting
45327
IMPORTANT
1. Lay out the required points on the wall or panel as shown in the drilling
dimension drawing.
Millimeters
(Inches)
21 (0.83)
35.5
(1.4)
58.5
(2.3)
35.5
(1.4)
58.5
(2.3)
35.5
(1.4)
2. Drill the necessary holes for the #6 self-tapping mounting screws.
3. Mount the mounting plate for the adapter module using two #6
self-tapping screws – 18 screws included for mounting up to 8 modules
and the adapter.
Make certain that the mounting plate is properly grounded to the
panel. Refer to Industrial Automation Wiring and Grounding
Guidelines, publication 1770-4.1
.
Publication 1794-6.5.12 - September 2011
4. Hold the adapter 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.
Mount the FLEX I/O Module on the Terminal Base Unit
The Thermocouple, RTD, and mV input module mounts on a 1794-TB3G or
1794-TB3GS terminal base unit.
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