Allen-Bradley MicroLogix 1200 User manual

MicroLogix™ 1200
Thermocouple/mV
Input Module
(Catalog Number 1762-IT4)
User Manual
AB Parts

Important User Information
Because of the variety of uses for the products described in this
publication, those responsible for the application and use of these
products 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. In no event will Allen-Bradley be responsible or
liable for indirect or consequential damage resulting from the use or
application of these products.
Any illustrations, charts, sample programs, and layout examples
shown in this publication are intended solely for purposes of
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 that 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 part, without written permission of Rockwell Automation, is
prohibited.
Throughout this publication, notes may be used to make you aware of
safety considerations. The following annotations and their
accompanying statements help you to identify a potential hazard,
avoid a potential hazard, and recognize the consequences of a
potential hazard:
WARNING
!
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.
ATTENTION
!
Identifies information about practices or
circumstances that can lead to personal injury or
death, property damage, or economic loss.
IMPORTANT Identifies information that is critical for successful
application and understanding of the product.

iPublication 1762-UM002A-EN-P - July 2002
Table of Contents
Preface
Who Should Use This Manual . . . . . . . . . . . . . . . . . . . . . . P-1
How to Use This Manual. . . . . . . . . . . . . . . . . . . . . . . . . . P-1
Manual Contents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . P-1
Related Documentation . . . . . . . . . . . . . . . . . . . . . . . . P-2
Conventions Used in This Manual . . . . . . . . . . . . . . . . . . . P-2
Rockwell Automation Support . . . . . . . . . . . . . . . . . . . . . . P-3
Local Product Support . . . . . . . . . . . . . . . . . . . . . . . . . P-3
Technical Product Assistance . . . . . . . . . . . . . . . . . . . . P-3
Your Questions or Comments on the Manual . . . . . . . . P-3
Chapter 1
Overview
General Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-1
Thermocouple/mV Inputs and Ranges . . . . . . . . . . . . . 1-1
Data Formats . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-2
Filter Frequencies . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-2
Hardware Features. . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-2
General Diagnostic Features. . . . . . . . . . . . . . . . . . . . . 1-4
System Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-4
System Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-4
Module Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-5
Module Field Calibration . . . . . . . . . . . . . . . . . . . . . . . 1-6
Chapter 2
Installation and Wiring
Compliance to European Union Directives . . . . . . . . . . . . . 2-1
EMC Directive . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-1
Low Voltage Directive . . . . . . . . . . . . . . . . . . . . . . . . . 2-2
Power Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-2
General Considerations . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-2
Hazardous Location Considerations . . . . . . . . . . . . . . . 2-3
Prevent Electrostatic Discharge . . . . . . . . . . . . . . . . . . . 2-3
Remove Power . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-4
Selecting a Location . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-4
Mounting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-5
Minimum Spacing . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-5
DIN Rail Mounting. . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-5
Panel Mounting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-6
System Assembly. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-7
Field Wiring Connections . . . . . . . . . . . . . . . . . . . . . . . . . 2-7
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Wiring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-9
Terminal Block Layout . . . . . . . . . . . . . . . . . . . . . . . . . 2-9
Labeling the Terminals. . . . . . . . . . . . . . . . . . . . . . . . . 2-9
Wiring the Finger-Safe Terminal Block . . . . . . . . . . . . . 2-10
Wire Size and Terminal Screw Torque . . . . . . . . . . . . . 2-11
Terminal Door Label . . . . . . . . . . . . . . . . . . . . . . . . . . 2-11
Wiring the Module. . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-11
Wiring Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-13
Cold Junction Compensation . . . . . . . . . . . . . . . . . . . . . . . 2-13
Calibration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-14
Chapter 3
Module Data, Status, and Channel
Configuration
Module Memory Map . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-1
Accessing Input Image File Data . . . . . . . . . . . . . . . . . . . . 3-1
Input Data File . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-2
Input Data Values . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-2
General Status Bits (S0 to S4) . . . . . . . . . . . . . . . . . . . . 3-2
Open-Circuit Flag Bits (OC0 to OC4) . . . . . . . . . . . . . . 3-3
Over-Range Flag Bits (O0 to O4) . . . . . . . . . . . . . . . . . 3-3
Under-Range Flag Bits (U0 to U4). . . . . . . . . . . . . . . . . 3-3
Configuring Channels . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-4
Configuration Data File . . . . . . . . . . . . . . . . . . . . . . . . 3-4
Channel Configuration . . . . . . . . . . . . . . . . . . . . . . . . . 3-4
Enabling or Disabling a Channel (Bit 15) . . . . . . . . . . . 3-6
Selecting Data Formats (Bits 14 through 12) . . . . . . . . . 3-6
Selecting Input Type (Bits 11 through 8). . . . . . . . . . . . 3-8
Selecting Temperature Units (Bit 7) . . . . . . . . . . . . . . . 3-9
Determining Open-Circuit Response (Bits 6 and 5) . . . . 3-9
Selecting Input Filter Frequency (Bits 2 through 0) . . . . 3-10
Selecting Enable/Disable Cyclic Calibration
(Word 4, Bit 0) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-14
Determining Effective Resolution and Range . . . . . . . . . . . 3-14
Determining Module Update Time. . . . . . . . . . . . . . . . . . . 3-33
Effects of Autocalibration on Module Update Time . . . . 3-34
Calculating Module Update Time . . . . . . . . . . . . . . . . . 3-35
Impact of Autocalibration on Module Startup
During Mode Change. . . . . . . . . . . . . . . . . . . . . . . . . . 3-37
Chapter 4
Diagnostics and Troubleshooting
Safety Considerations . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-1
Indicator Lights . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-1
Stand Clear of Equipment. . . . . . . . . . . . . . . . . . . . . . . 4-2
Program Alteration. . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-2
Safety Circuits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-2

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Module Operation vs. Channel Operation . . . . . . . . . . . . . 4-2
Power-up Diagnostics . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-3
Channel Diagnostics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-3
Invalid Channel Configuration Detection. . . . . . . . . . . . 4-3
Over- or Under-Range Detection . . . . . . . . . . . . . . . . . 4-3
Open-Circuit Detection . . . . . . . . . . . . . . . . . . . . . . . . 4-4
Non-critical vs. Critical Module Errors . . . . . . . . . . . . . . . . 4-4
Module Error Definition Table . . . . . . . . . . . . . . . . . . . . . . 4-4
Module Error Field. . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-4
Extended Error Information Field . . . . . . . . . . . . . . . . . 4-5
Error Codes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-6
Contacting Rockwell Automation . . . . . . . . . . . . . . . . . . . . 4-7
Appendix A
Specifications
General Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-1
Input Specifications. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-2
Repeatability at 25°C (77°F) . . . . . . . . . . . . . . . . . . . . . . . A-3
Accuracy. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-4
Accuracy Versus Thermocouple Temperature and Filter
Frequency . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-5
Appendix B
Two’s Complement Binary
Numbers
Positive Decimal Values . . . . . . . . . . . . . . . . . . . . . . . . . . B-1
Negative Decimal Values. . . . . . . . . . . . . . . . . . . . . . . . . . B-2
Appendix C
Thermocouple Descriptions
International Temperature Scale of 1990. . . . . . . . . . . . . . . C-1
Type B Thermocouples . . . . . . . . . . . . . . . . . . . . . . . . . . . C-1
Type E Thermocouples . . . . . . . . . . . . . . . . . . . . . . . . . . . C-3
Type J Thermocouples . . . . . . . . . . . . . . . . . . . . . . . . . . . C-5
Type K Thermocouples. . . . . . . . . . . . . . . . . . . . . . . . . . . C-7
Type N Thermocouples. . . . . . . . . . . . . . . . . . . . . . . . . . . C-9
Type R Thermocouples . . . . . . . . . . . . . . . . . . . . . . . . . . C-11
Type S Thermocouples . . . . . . . . . . . . . . . . . . . . . . . . . . C-12
Type T Thermocouples . . . . . . . . . . . . . . . . . . . . . . . . . . C-14
References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . C-17
Appendix D
Using Thermocouple Junctions
Using a Grounded Junction Thermocouple . . . . . . . . . . . . D-1
Using an Ungrounded (Isolated) Junction Thermocouple . . D-2
Using an Exposed Junction Thermocouple. . . . . . . . . . . . . D-3
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Appendix E
Module Configuration Using
MicroLogix 1200 and RSLogix 500
Module Addressing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . E-1
1762-IT4 Configuration File . . . . . . . . . . . . . . . . . . . . . E-2
Configuration Using RSLogix 500 Version 5.50 or Higher . . E-2
Generic Extra Data Configuration . . . . . . . . . . . . . . . . . E-6
Configuration Using RSLogix 500 Version 5.2 or Lower. . . . E-7
Glossary
Index

1Publication 1762-UM002A-EN-P - July 2002
Preface
Read this preface to familiarize yourself with the rest of the manual.
This preface covers the following topics:
•who should use this manual
•how to use this manual
•related publications
•conventions used in this manual
•Rockwell Automation support
Who Should Use This
Manual
Use this manual if you are responsible for designing, installing,
programming, or troubleshooting control systems that use
Allen-Bradley MicroLogix™ 1200.
How to Use This Manual
As much as possible, we organized this manual to explain, in a
task-by-task manner, how to install, configure, program, operate and
troubleshoot a control system using the 1762-IT4.
Manual Contents
If you want... See
An overview of the thermocouple/mV input module Chapter 1
Installation and wiring guidelines Chapter 2
Module addressing, configuration and status information Chapter 3
Information on module diagnostics and troubleshooting Chapter 4
Specifications for the input module Appendix A
Information on understanding two’s complement binary numbers Appendix B
Thermocouple descriptions Appendix C
Information on using the different types of thermocouple junctions Appendix D
An example of configuration using RSLogix 500 Appendix E
AB Parts

Publication 1762-UM002A-EN-P - July 2002
Preface 2
Related Documentation
The table below provides a listing of publications that contain
important information about MicroLogix 1200 systems.
If you would like a manual, you can:
•download a free electronic version from the internet at
www.theautomationbookstore.com
•purchase a printed manual by:
–contacting your local distributor or Rockwell Automation
representative
–visiting www.theautomationbookstore.com and placing
your order
–calling 1.800.963.9548 (USA/Canada) or 001.330.725.1574
(Outside USA/Canada)
Conventions Used in This
Manual
The following conventions are used throughout this manual:
•Bulleted lists (like this one) provide information not procedural
steps.
•Numbered lists provide sequential steps or hierarchical
information.
•Italic type is used for emphasis.
For Read this document Document number
A user manual containing information on how to install,
use and program your MicroLogix 1200 controller MicroLogix™ 1200 User Manual 1762-UM001
An overview of the MicroLogix 1200 System, including
1762 Expansion I/O. MicroLogix™ 1200 Technical Data 1762-TD001
Information on the MicroLogix 1200 instruction set. MicroLogix 1200 and MicroLogix 1500 Programmable
Controllers Instruction Set Reference Manual 1762-RM001
In-depth information on grounding and wiring
Allen-Bradley programmable controllers. Allen-Bradley Programmable Controller Grounding and Wiring Guidelines 1770-4.1

Publication 1762-UM002A-EN-P - July 2002
Preface 3
Rockwell Automation
Support
Rockwell Automation offers support services worldwide, with over
75 Sales/Support Offices, 512 authorized distributors and 260
authorized Systems Integrators located throughout the United States
alone, plus Rockwell Automation representatives in every major
country in the world.
Local Product Support
Contact your local Rockwell Automation representative for:
•sales and order support
•product technical training
•warranty support
•support service agreement
Technical Product Assistance
If you need to contact Rockwell Automation for technical assistance,
please review the information in Chapter 4, Diagnostics and
Troubleshooting first. Then call your local Rockwell Automation
representative.
Your Questions or Comments on the Manual
If you find a problem with this manual, please notify us. If you have
any suggestions for how this manual could be made more useful to
you, please contact us at the address below:
Rockwell Automation
Automation Control and Information Group
Technical Communication, Dept. A602V
P.O. Box 2086
Milwaukee, WI 53201-2086
AB Parts

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Preface 4