Allen-Bradley MicroLogix 1200 User Manual
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Allen-Bradley MicroLogix 1200 User Manual

Allen-Bradley MicroLogix 1200 User Manual

Thermocouple/mv input module
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MicroLogix™ 1200
Thermocouple/mV
Input Module
(Catalog Number 1762-IT4)
User Manual
AB Parts
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Summary of Contents for Allen-Bradley MicroLogix 1200

  • Page 1 MicroLogix™ 1200 Thermocouple/mV Input Module (Catalog Number 1762-IT4) User Manual AB Parts...
  • Page 2 In no event will Allen-Bradley be responsible or liable for indirect or consequential damage resulting from the use or application of these products.

  • Page 3: Table Of Contents

    Table of Contents Preface Who Should Use This Manual ..... . P-1 How to Use This Manual ......P-1 Manual Contents .
  • Page 4 Table of Contents Wiring ........2-9 Terminal Block Layout .
  • Page 5 Table of Contents Module Operation vs. Channel Operation ... . . 4-2 Power-up Diagnostics ......4-3 Channel Diagnostics .
  • Page 6 1762-IT4 Configuration File ..... E-2 MicroLogix 1200 and RSLogix 500 Configuration Using RSLogix 500 Version 5.50 or Higher . . E-2 Generic Extra Data Configuration .

  • Page 7: Preface

    Use this manual if you are responsible for designing, installing, programming, or troubleshooting control systems that use Manual 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.

  • Page 8: Related Documentation

    A user manual containing information on how to install, MicroLogix™ 1200 User Manual 1762-UM001 use and program your MicroLogix 1200 controller An overview of the MicroLogix 1200 System, including MicroLogix™ 1200 Technical Data 1762-TD001 1762 Expansion I/O. Information on the MicroLogix 1200 instruction set.

  • Page 9: Rockwell Automation Support

    Preface Rockwell Automation Rockwell Automation offers support services worldwide, with over 75 Sales/Support Offices, 512 authorized distributors and 260 Support 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: •...
  • Page 10 Preface Publication 1762-UM002A-EN-P - July 2002...

  • Page 11: Overview

    Chapter Overview This chapter describes the 1762-IT4 Thermocouple/mV Input Module and explains how the module reads thermocouple or millivolt analog input data. Included is information about: • the module’s hardware and diagnostic features • system and module operation • calibration General Description The thermocouple/mV input module supports thermocouple and millivolt signal measurement.

  • Page 12: Data Formats

    Overview Millivolt Input Type Range ± 50 mV -50 to +50 mV ± 100 mV -100 to +100 mV Data Formats The data can be configured on board each module as: • engineering units x 1 • engineering units x 10 •...
  • Page 13 Overview The illustration below shows the module’s hardware features. Item Description upper panel mounting tab lower panel mounting tab power diagnostic LED module door with terminal identification label bus connector cover flat ribbon cable with bus connector (female) terminal block DIN rail latch pull loop AB Parts...

  • Page 14: General Diagnostic Features

    Overview General Diagnostic Features The module contains a diagnostic LED that helps you identify the source of problems that may occur during power-up or during normal channel operation. The LED indicates both status and power. Power-up and channel diagnostics are explained in Chapter 4, Diagnostics and Troubleshooting.

  • Page 15: Module Operation

    Overview Module Operation When the module receives a differential input from an analog device, the module’s circuitry multiplexes the input into an A/D converter. The converter reads the signal and converts it as required for the type of input. The module also continuously samples the CJC sensor and compensates for temperature changes at the terminal block cold junction, between the thermocouple wire and the input channel.

  • Page 16: Module Field Calibration

    Overview Module Field Calibration The module provides autocalibration, which compensates for offset and gain drift of the A/D converter caused by a temperature change within the module. An internal, high-precision, low drift voltage and system ground reference is used for this purpose. The input module performs autocalibration when a channel is initially enabled.

  • Page 17: Installation And Wiring

    Chapter Installation and Wiring This chapter tells you how to: • determine the power requirements for the modules • avoid electrostatic damage • install the module • wire the module’s terminal block • wire input devices Compliance to European This product is approved for installation within the European Union and EEA regions.

  • Page 18: Low Voltage Directive

    Programmable Controllers, Part 2 – Equipment Requirements and Tests. For specific information required by EN61131-2, 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 •...

  • Page 19: Hazardous Location Considerations

    Installation and Wiring Hazardous Location Considerations This equipment is suitable for use in Class I, Division 2, Groups A, B, C, D or non-hazardous locations only. The following WARNING statement applies to use in hazardous locations. EXPLOSION HAZARD WARNING • Substitution of components may impair suitability for Class I, Division 2.

  • Page 20: Remove Power

    Installation and Wiring Remove Power Remove power before removing or installing this ATTENTION module. When you remove or install a module with power applied, an electrical arc may occur. An electrical arc can cause personal injury or property damage by: •...

  • Page 21: Mounting

    Installation and Wiring Mounting Do not remove protective debris strip until after the ATTENTION module and all other equipment near the module is mounted and wiring is complete. Once wiring is complete and the module is free of debris, carefully remove protective debris strip.

  • Page 22: Panel Mounting

    Installation and Wiring Use DIN rail end anchors (Allen-Bradley part number 1492-EA35 or 1492-EAH35) for environments with vibration or shock concerns. End Anchor End Anchor For environments with extreme vibration and shock concerns, use the panel mounting method described below, instead of DIN rail mounting.

  • Page 23: System Assembly

    Installation and Wiring System Assembly The expansion I/O module is attached to the controller or another I/O module by means of a ribbon cable after mounting as shown below. Use the pull loop on the connector to disconnect modules. Do not pull on the ribbon cable. EXPLOSION HAZARD ATTENTION •...
  • Page 24 Installation and Wiring Terminal Block • Do not tamper with or remove the CJC sensor on the terminal block. Removal of the sensor reduces accuracy. • For millivolt sensors, use Belden 8761 shielded, twisted-pair wire (or equivalent) to ensure proper operation and high immunity to electrical noise.

  • Page 25: Wiring

    DIN rail mounting screw. • Refer to Industrial Automation Wiring and Grounding Guidelines, Allen-Bradley publication 1770-4.1, for additional information. Noise Prevention • Route field wiring away from any other wiring and as far as possible from sources of electrical noise, such as motors, transformers, contactors, and ac devices.

  • Page 26: Wiring The Finger-Safe Terminal Block

    2-10 Installation and Wiring Wiring the Finger-Safe Terminal Block Be careful when stripping wires. Wire fragments ATTENTION that fall into a module could cause damage when power is applied. Once wiring is complete, ensure the module is free of all metal fragments. When wiring the terminal block, keep the finger-safe cover in place.

  • Page 27: Wire Size And Terminal Screw Torque

    Installation and Wiring 2-11 Wire Size and Terminal Screw Torque Each terminal accepts up to two wires with the following restrictions: Wire Type Wire Size Terminal Screw Torque Solid Cu-90°C (194°F) #14 to #22 AWG 0.904 Nm (8 in-lbs) Stranded Cu-90°C (194°F) #16 to #22 AWG 0.904 Nm (8 in-lbs)
  • Page 28 2-12 Installation and Wiring Cut foil shield cable and drain wire signal wire signal wire foil shield signal wire signal wire drain wire To wire your module follow these steps. 1. At each end of the cable, strip some casing to expose the individual wires.

  • Page 29: Wiring Diagram

    Installation and Wiring 2-13 Wiring Diagram grounded thermocouple IN 0+ CJC sensor CJC+ IN 0- ungrounded thermocouple CJC - IN 1 + within 10V dc IN 2+ IN 1- IN 2- IN 3+ grounded thermocouple IN 3- When using an ungrounded thermocouple, the shield must be connected to ground at the module end.

  • Page 30: Calibration

    2-14 Installation and Wiring Calibration The thermocouple module is initially calibrated at the factory. The module also has an autocalibration function. When an autocalibration cycle takes place, the module’s multiplexer is set to system ground potential and an A/D reading is taken. The A/D converter then sets its internal input to the module’s precision voltage source, and another reading is taken.

  • Page 31: Module Memory Map

    Chapter Module Data, Status, and Channel Configuration After installing the 1762-IT4 thermocouple/mV input module, you must configure it for operation using the programming software compatible with the controller (for example, RSLogix 500). Once configuration is complete and reflected in the ladder logic, you need to operate the module and verify its configuration.

  • Page 32: Input Data File

    (proper configuration) but before the A/D converter can provide valid (properly configured) data to the MicroLogix 1200 controller. The following information highlights the bit operation of the Data Not Valid condition.

  • Page 33: Open-Circuit Flag Bits (Oc0 To Oc4)

    Module Data, Status, and Channel Configuration remains until the module begins converting analog data for the previously accepted new configuration. When conversion begins, the bit condition is reset (0). The amount of time it takes for the module to begin the conversion process depends on the number of channels being configured and the amount of configuration data downloaded by the controller.

  • Page 34: Configuring Channels

    Module Data, Status, and Channel Configuration Configuring Channels After module installation, you must configure operation details, such as thermocouple type, temperature units, etc., for each channel. Channel configuration data for the module is stored in the controller configuration file, which is both readable and writable. The configuration data file is shown below.
  • Page 35 Module Data, Status, and Channel Configuration Make these bit settings To Select Filter 10 Hz Frequency 60 Hz 50 Hz 250Hz 500 Hz 1 kHz Open Upscale Circuit Downscale Hold Last State Zero Tempera- Degrees C ture Units Degrees F Input Thermocouple Type...

  • Page 36: Enabling Or Disabling A Channel (Bit 15)

    Module Data, Status, and Channel Configuration Enabling or Disabling a Channel (Bit 15) You can enable or disable each of the four channels individually using bit 15. The module only scans enabled channels. Enabling a channel forces it to be recalibrated before it measures input data. Disabling a channel sets the channel data word to zero.
  • Page 37 Module Data, Status, and Channel Configuration The engineering units data formats represent real engineering temperature units provided by the module to the controller. The raw/proportional counts, scaled-for-PID and percent of full-scale data formats may yield the highest effective resolutions, but may also require that you convert channel data to real engineering units in your control program.

  • Page 38: Selecting Input Type (Bits 11 Through 8)

    To obtain the value, the module scales the input signal range to a 0 to +16383 range, which is standard to the PID algorithm for the MicroLogix 1200 and other Allen-Bradley controllers (e.g. SLC). For example, if type J thermocouple is used, the lowest temperature for the thermocouple is -210°C, which corresponds to 0 counts.

  • Page 39: Selecting Temperature Units (Bit 7)

    Module Data, Status, and Channel Configuration Selecting Temperature Units (Bit 7) The module supports two different linearized/scaled ranges for thermocouples, degrees Celsius (°C) and degrees Fahrenheit (°F). Bit 7 is ignored for millivolt input types, or when raw/proportional, scaled-for-PID, or percent data formats are used. If you are using engineering units x 1 data format IMPORTANT and degrees Fahrenheit temperature units,...

  • Page 40: Selecting Input Filter Frequency (Bits 2 Through 0)

    3-10 Module Data, Status, and Channel Configuration Table 3.2 Open-Circuit Response Definitions Response Definition Option Upscale Sets the input data value to full upper scale value of channel data word. The full-scale value is determined by the selected input type and data format. Downscale Sets the input data value to full lower scale value of channel data word.
  • Page 41 Module Data, Status, and Channel Configuration 3-11 Common Mode Rejection is better than 115 dB at 50 and 60 Hz, with the 50 and 60 Hz filters selected, respectively, or with the 10Hz filter selected. The module performs well in the presence of common mode noise as long as the signals applied to the user positive and negative input terminals do not exceed the common mode voltage rating (±10V) of the module.
  • Page 42 3-12 Module Data, Status, and Channel Configuration Channel Cut-Off Frequency The filter cut-off frequency, -3 dB, is the point on the frequency response curve where frequency components of the input signal are passed with 3 dB of attenuation. The following table shows cut-off frequencies for the supported filters.
  • Page 43 Module Data, Status, and Channel Configuration 3-13 Figure 3.1 Frequency Response Graphs 10 Hz Input Filter Frequency 50 Hz Input Filter Frequency –3 dB –3 dB –20 –20 –40 –40 –60 –60 –80 –80 -100 -100 -120 -120 -140 -140 -160 -160 -180...

  • Page 44: Selecting Enable/Disable Cyclic Calibration (Word 4, Bit 0)

    3-14 Module Data, Status, and Channel Configuration The cut-off frequency for each channel is defined by its filter frequency selection. Choose a filter frequency so that your fastest changing signal is below that of the filter’s cut-off frequency. The cut-off frequency should not be confused with the update time. The cut-off frequency relates to how the digital filter attenuates frequency components of the input signal.
  • Page 45 Module Data, Status, and Channel Configuration 3-15 Figure 3.2 Effective Resolution Versus Input Filter Selection for Type B Thermocouples Using 10, 50, and 60 Hz Filters 10 Hz 50 Hz 60 Hz 1000 1200 1400 1600 1800 2000 Temperature (°C) 4.
  • Page 46 3-16 Module Data, Status, and Channel Configuration Figure 3.3 Effective Resolution Versus Input Filter Selection for Type B Thermocouples Using 250, 500, and 1k Hz Filte 250 Hz 500 Hz 1000 Hz 1000 1200 1400 1600 1800 2000 Temperature (°C) 250 Hz 500 Hz 1000 Hz...
  • Page 47 Module Data, Status, and Channel Configuration 3-17 Figure 3.4 Effective Resolution Versus Input Filter Selection for Type C Thermocouples Using 10, 50, and 60 Hz Filters 0. 8 0. 7 0. 6 10 Hz 0. 5 50 Hz 0. 4 60 Hz 0.
  • Page 48 3-18 Module Data, Status, and Channel Configuration Figure 3.5 Effective Resolution Versus Input Filter Selection for Type C Thermocouples Using 250, 500, and 1k Hz Filters 250 Hz 500 Hz 1000 Hz 1200 1600 2000 2400 Temperature (°C) 250 Hz 500 Hz 1000 Hz 1000...
  • Page 49 Module Data, Status, and Channel Configuration 3-19 Figure 3.6 Effective Resolution Versus Input Filter Selection for Type E Thermocouples Using 10, 50, and 60 Hz Filters 10 Hz 50 Hz 60 Hz -400 -200 1000 Temperature (°C) 10 Hz 50 Hz 60 Hz -500 1000...
  • Page 50 3-20 Module Data, Status, and Channel Configuration Figure 3.7 Effective Resolution Versus Input Filter Selection for Type E Thermocouples Using 250, 500, and 1k Hz Filters 250 Hz 500 Hz 1000 Hz -400 -200 1000 Temperature (°C) 250 Hz 500 Hz 1000 Hz -500 1000...
  • Page 51 Module Data, Status, and Channel Configuration 3-21 Figure 3.8 Effective Resolution Versus Input Filter Selection for Type J Thermocouples Using 10, 50, and 60 Hz Filters 10 Hz 50 Hz 60 Hz -400 -200 1000 1200 Temperature (°C) 10 Hz 50 Hz 60 Hz -400...
  • Page 52 3-22 Module Data, Status, and Channel Configuration Figure 3.9 Effective Resolution Versus Input Filter Selection for Type J Thermocouples Using 250, 500, and 1k Hz Filters 250 Hz 500 Hz 1000 Hz -400 -200 1000 1200 Temperature (°C) 250 Hz 500 Hz 1000 Hz -400...
  • Page 53 Module Data, Status, and Channel Configuration 3-23 Figure 3.10 Effective Resolution Versus Input Filter Selection for Type K Thermocouples Using 10, 50, and 60 Hz Filters 5. 5 5. 0 4. 5 4. 0 10 Hz 3. 5 3. 0 50 Hz 2.
  • Page 54 3-24 Module Data, Status, and Channel Configuration Figure 3.11 Effective Resolution Versus Input Filter Selection for Type K Thermocouples Using 250, 500, and 1k Hz Filters 250Hz 500Hz 1000 Hz -400 -200 1000 1200 Temperature (°C) 250 Hz 500 Hz 1000 Hz -500 1000...
  • Page 55 Module Data, Status, and Channel Configuration 3-25 Figure 3.12 Effective Resolution Versus Input Filter Selection for Type N Thermocouples Using 10, 50, and 60 Hz Filters 0. 8 0. 7 0. 6 10 H z 0. 5 50 H z 0.
  • Page 56 3-26 Module Data, Status, and Channel Configuration Figure 3.13 Effective Resolution Versus Input Filter Selection for Type N Thermocouples Using 250, 500, and 1k Hz Filters 250 Hz 500 Hz 1000 Hz -400 -200 1000 1200 1400 Temperature (°C) 250 Hz 500 Hz 1000 Hz -500...
  • Page 57 Module Data, Status, and Channel Configuration 3-27 Figure 3.14 Effective Resolution Versus Input Filter Selection for Type R Thermocouples Using 10, 50, and 60 Hz Filters 10 Hz 50 Hz 60 Hz 1000 1200 1400 1600 1800 Temperature (°C) 10 Hz 50 Hz 60 Hz 1000...
  • Page 58 3-28 Module Data, Status, and Channel Configuration Figure 3.15 Effective Resolution Versus Input Filter Selection for Type R Thermocouples Using 250, 500, and 1k Hz Filters 250 Hz 500 Hz 1000Hz 1000 1200 1400 1600 1800 Temperature (°C) 250 Hz 500 Hz 1000 Hz 1000...
  • Page 59 Module Data, Status, and Channel Configuration 3-29 Figure 3.16 Effective Resolution Versus Input Filter Selection for Type S Thermocouples Using 10, 50, and 60 Hz Filters 1. 4 1. 2 1. 0 10 H z 0. 8 50 H z 0.
  • Page 60 3-30 Module Data, Status, and Channel Configuration Figure 3.17 Effective Resolution Versus Input Filter Selection for Type S Thermocouples Using 250, 500, and 1k Hz Filters 250 Hz 500 Hz 1000 Hz 1000 1200 1400 1600 1800 Temperature (°C) 250 Hz 500 Hz 1000 Hz 1000...
  • Page 61 Module Data, Status, and Channel Configuration 3-31 Figure 3.18 Effective Resolution Versus Input Filter Selection for Type T Thermocouples Using 10, 50, and 60 Hz Filters 10 Hz 50 Hz 60 Hz -300 -200 -100 Temperature (°C) 10 Hz 50 Hz 60 Hz -600 -400...
  • Page 62 3-32 Module Data, Status, and Channel Configuration Figure 3.19 Effective Resolution Versus Input Filter Selection for Type T Thermocouples Using 250, 500, and 1k Hz Filters 250 Hz 500 Hz 1000 Hz -300 -200 -100 Temperature (°C) 250 Hz 500 Hz 1000 Hz -600 -400...

  • Page 63: Determining Module Update Time

    Module Data, Status, and Channel Configuration 3-33 Table 3.4 Effective Resolution vs. Input Filter Selection for Millivolt Inputs Filter Frequency ±50mV ±100mV 6 µV 6 µV 10 Hz 9 µV 12 µV 50 Hz 9 µV 12 µV 60 Hz 125 µV 150 µV 250 Hz...

  • Page 64: Effects Of Autocalibration On Module Update Time

    3-34 Module Data, Status, and Channel Configuration Channel update time is dependent upon the input filter selection. The following table shows the channel update times. Table 3.5 Channel Update Time Filter Frequency Channel Update Time 10 Hz 303 ms 50 Hz 63 ms 60 Hz 53 ms...

  • Page 65: Calculating Module Update Time

    Module Data, Status, and Channel Configuration 3-35 separate ADC self-calibration and offset calibration cycles only if their filter configurations are different than those of previously calibrated channels. Following all input channel calibration cycles, the CJC sensor channel receives a separate ADC self-calibration cycle. The time added to this cycle is determined by the filter setting for the CJC, which is set to the lowest filter setting of any input configured as a thermocouple.
  • Page 66 3-36 Module Data, Status, and Channel Configuration 2.Three Channels Enabled for Different Inputs EXAMPLE Channel 0 Input: Type J Thermocouple with 10 Hz filter Channel 1 Input: Type J Thermocouple with 60 Hz filter Channel 2 Input: ±100 mV with 250 Hz filter From Table 3.5, Channel Update Time, on page 3-34: Module Update Time = Ch 0 Update Time + Ch 1 Update Time...

  • Page 67: Impact Of Autocalibration On Module Startup During Mode Change

    Module Data, Status, and Channel Configuration 3-37 Impact of Autocalibration on Module Startup During Mode Change Regardless of the selection of the Enable/Disable Cyclic Calibration function, an autocalibration cycle occurs automatically on a mode change from Program-to-Run and on subsequent module startups/initialization for all configured channels.
  • Page 68 3-38 Module Data, Status, and Channel Configuration Publication 1762-UM002A-EN-P - July 2002...

  • Page 69: Safety Considerations

    Chapter Diagnostics and Troubleshooting This chapter describes troubleshooting the thermocouple/mV input module. This chapter contains information on: • safety considerations while troubleshooting • internal diagnostics during module operation • module errors • contacting Rockwell Automation for technical assistance Safety Considerations Safety considerations are an important element of proper troubleshooting procedures.

  • Page 70: Stand Clear Of Equipment

    Diagnostics and Troubleshooting Stand Clear of Equipment When troubleshooting any system problem, have all personnel remain clear of the equipment. The problem could be intermittent, and sudden unexpected machine motion could occur. Have someone ready to operate an emergency stop switch in case it becomes necessary to shut off power.

  • Page 71: Power-Up Diagnostics

    Diagnostics and Troubleshooting Power-up Diagnostics At module power-up, a series of internal diagnostic tests are performed. If these diagnostic tests are not successfully completed, the module status LED remains off and a module error is reported to the controller. If module status Indicated Corrective action: LED is:...

  • Page 72: Open-Circuit Detection

    Diagnostics and Troubleshooting Open-Circuit Detection On each scan, the module performs an open-circuit test on all enabled channels. Whenever an open-circuit condition occurs, the open-circuit bit for that channel is set in input data word 6. Possible causes of an open circuit include: •...

  • Page 73: Extended Error Information Field

    Diagnostics and Troubleshooting in the controller’s I/O status file. Refer to your controller manual for details. Table 4.2 Module Error Types Error Type Module Error Description Field Value Bits 11 through 9 (binary) No Errors No error is present. The extended error field holds no additional information.

  • Page 74: Error Codes

    Diagnostics and Troubleshooting Error Codes The table below explains the extended error code. Table 4.3 Extended Error Codes Error Type Module Extended Error Error Description Error Information Equivalent Code Code Binary Binary No Error X000 0 0000 0000 No Error General Common X200 0 0000 0000...

  • Page 75: Contacting Rockwell Automation

    Diagnostics and Troubleshooting Contacting Rockwell If you need to contact Rockwell Automation for assistance, please have the following information available when you call: Automation • a clear statement of the problem, including a description of what the system is actually doing. Note the LED state; also note data and configuration words for the module.
  • Page 76 Diagnostics and Troubleshooting Publication 1762-UM002A-EN-P - July 2002...

  • Page 77: General Specifications

    Appendix Specifications General Specifications Specification Value Dimensions 90 mm (height) x 87 mm (depth) x 40 mm (width) height including mounting tabs is 110 mm 3.54 in. (height) x 3.43 in. (depth) x 1.58 in. (width) height including mounting tabs is 4.33 in. Approximate Shipping Weight 220g (0.53 lbs.) (with carton)

  • Page 78: Input Specifications

    Specifications Specification Value Electrical /EMC: The module has passed testing at the following levels: • ESD Immunity • 4 kV contact, 8 kV air, 4 kV indirect (EN61000-4-2) • Radiated Immunity • 10 V/m , 80 to 1000 MHz, 80% amplitude (EN61000-4-3) modulation, +900 MHz keyed carrier •...

  • Page 79: Repeatability At 25°C (77°F

    Specifications Specification Value Module Error over Full See “Accuracy” on page A-4. Temperature Range (0 to +55°C [+32°F to +131°F]) CJC Accuracy ±1.3°C (±2.34°F) Maximum Overload at Input ±35V dc continuous Terminals Input Group to Bus Isolation 720V dc for 1 minute (qualification test) 30V ac/30V dc working voltage Input Channel Configuration via configuration software screen or the user program (by writing a unique bit pattern into the module’s configuration...

  • Page 80: Accuracy

    Specifications Accuracy With Autocalibration Enabled Without Autocalibration (2) (3) (2) (4) Accuracy for 10 Hz, 50 Hz and 60 Maximum Temperature Drift Hz Filters (max.) Input Type at 25°C [77°F] at 0 to 60°C at 0 to 60°C [32 to 140°F] Ambient [32 to 140°F] Ambient...

  • Page 81: Accuracy Versus Thermocouple Temperature And Filter Frequency

    Specifications Accuracy Versus Thermocouple Temperature and Filter Frequency The following graphs show the module’s accuracy when operating at 25°C for each thermocouple type over the thermocouple’s temperature range for each frequency. The effect of errors in cold junction compensation is not included. Figure A.1 Module Accuracy at 25°C (77°F) Ambient for Type B Thermocouple Using 10, 50, and 60 Hz Filter 10 Hz...
  • Page 82 Specifications Figure A.2 Module Accuracy at 25°C (77°F) Ambient for Type B Thermocouple Using 250, 500, and 1 kHz Filter 250 Hz 500 Hz 1000 Hz 1000 1200 1400 1600 1800 2000 Thermocouple Temperature °C 250 Hz 500 Hz 1000 Hz 1000 1500 2000...
  • Page 83 Specifications Figure A.3 Module Accuracy at 25°C (77°F) Ambient for Type C Thermocouple Using 10, 50, and 60 Hz Filter 1. 8 1. 6 1. 4 10 Hz 1. 2 50 Hz 1. 0 0. 8 60 Hz 0. 6 0.
  • Page 84 Specifications Figure A.4 Module Accuracy at 25°C (77°F) Ambient for Type C Thermocouple Using 250, 500, and 1 kHz Filter 250 Hz 500 Hz 1000 Hz 1200 1600 2000 2400 Thermocouple Temperature °C 250 Hz 500 Hz 1000 Hz 1000 1500 2000 2500...
  • Page 85 Specifications Figure A.5 Module Accuracy at 25°C (77°F) Ambient for Type E Thermocouple Using 10, 50, and 60 Hz Filter 5. 0 4. 0 10 Hz 3. 0 50 Hz 2. 0 60 Hz 1. 0 0. 0 -400 -200 1000 Thermocouple Temperature °C 9.
  • Page 86 A-10 Specifications Figure A.6 Module Accuracy at 25°C (77°F) Ambient for Type E Thermocouple Using 250, 500, and 1 kHz Filter 250 Hz 500 Hz 1000 Hz -400 -200 1000 Thermocouple Temperature °C 250 Hz 500 Hz 1000 Hz -500 1000 1500 2000...
  • Page 87 Specifications A-11 Figure A.7 Module Accuracy at 25°C (77°F) Ambient for Type J Thermocouple Using 10, 50, and 60 Hz Filter 10 Hz 50 Hz 60 Hz -400 -200 1000 1200 Thermocouple Temperature °C 10 Hz 50 Hz 60 Hz -400 1200 1600...
  • Page 88 A-12 Specifications Figure A.8 Module Accuracy at 25°C (77°F) Ambient for Type J Thermocouple Using 250, 500, and 1 kHz Filter 250 Hz 500 Hz 1000 Hz -400 -200 1000 1200 Thermocouple Temperature °C 250 Hz 500 Hz 1000 Hz -400 1200 1600...
  • Page 89 Specifications A-13 Figure A.9 Module Accuracy at 25°C (77°F) Ambient for Type K Thermocouple Using 10, 50, and 60 Hz Filter 9. 0 8. 0 7. 0 6. 0 10 Hz 5. 0 50 Hz 4. 0 60 Hz 3. 0 2.
  • Page 90 A-14 Specifications Figure A.10 Module Accuracy at 25°C (77°F) Ambient for Type K Thermocouple Using 250, 500, and 1 kHz Filter 250 Hz 500 Hz 1000 Hz -400 -200 1000 1200 1400 Thermocouple Temperature °C 250 Hz 500 Hz 1000 Hz -500 1000 1500...
  • Page 91 Specifications A-15 Figure A.11 Module Accuracy at 25°C (77°F) Ambient for Type N Thermocouple Using 10, 50, and 60 Hz Filter 10 H z 50 H z 60 H z -400 -200 1000 1200 1400 Thermocouple Temperature °C 10 H z 50 H z 60 H z -500...
  • Page 92 A-16 Specifications Figure A.12 Module Accuracy at 25°C (77°F) Ambient for Type N Thermocouple Using 250, 500, and 1 kHz Filter 250 Hz 500 Hz 1000 Hz -400 -200 1000 1200 1400 Thermocouple Temperature °C 250 Hz 500 Hz 1000 Hz -500 1000 1500...
  • Page 93 Specifications A-17 Figure A.13 Module Accuracy at 25°C (77°F) Ambient for Type R Thermocouple Using 10, 50, and 60 Hz Filter 10 Hz 50 Hz 60 Hz 1000 1200 1400 1600 1800 Thermocouple Temperature °C 4. 5 4. 0 3. 5 3.
  • Page 94 A-18 Specifications Figure A.14 Module Accuracy at 25°C (77°F) Ambient for Type R Thermocouple Using 250, 500, and 1 kHz Filter 250 Hz 500 Hz 1000 Hz 1000 1200 1400 1600 1800 Thermocouple Temperature °C 250 Hz 500 Hz 1000 Hz 1000 1500 2000...
  • Page 95 Specifications A-19 Figure A.15 Module Accuracy at 25°C (77°F) Ambient for Type S Thermocouple Using 10, 50, and 60 Hz Filter 2. 5 2. 0 10 Hz 1. 5 50 Hz 1. 0 60 Hz 0. 5 0. 0 1000 1200 1400 1600...
  • Page 96 A-20 Specifications Figure A.16 Module Accuracy at 25°C (77°F) Ambient for Type S Thermocouple Using 250, 500, and 1 kHz Filter 250 Hz 500 Hz 1000 Hz 1000 1200 1400 1600 1800 Thermocouple Temperature °C 250 Hz 500 Hz 1000 Hz 1000 1500 2000...
  • Page 97 Specifications A-21 Figure A.17 Module Accuracy at 25°C (77°F) Ambient for Type T Thermocouple Using 10, 50, and 60 Hz Filter 10 Hz 50 Hz 60 Hz -300 -200 -100 Thermocouple Temperature °C 10 Hz 50 Hz 60 Hz -600 -400 -200 Thermocouple Temperature °F...
  • Page 98 A-22 Specifications Figure A.18 Module Accuracy at 25°C (77°F) Ambient for Type T Thermocouple Using 250, 500, and 1 kHz Filter 250 Hz 500 Hz 1000 Hz -300 -200 -100 Thermocouple Temperature °C 250 Hz 500 Hz 1000 Hz -600 -400 -200 Thermocouple Temperature °F...

  • Page 99: Positive Decimal Values

    Appendix Two’s Complement Binary Numbers The processor memory stores 16-bit binary numbers. Two’s complement binary is used when performing mathematical calculations internal to the processor. Analog input values from the analog modules are returned to the processor in 16-bit two’s complement binary format.

  • Page 100: Negative Decimal Values

    Two’s Complement Binary Numbers Negative Decimal Values In two’s complement notation, the far left position is always 1 for negative values. The equivalent decimal value of the binary number is obtained by subtracting the value of the far left position, 32768, from the sum of the values of the other positions.

  • Page 101: International Temperature Scale Of 1990

    Appendix Thermocouple Descriptions The information in this appendix was extracted from the NIST Monograph 175 issued in January 1990, which supersedes the IPTS-68 Monograph 125 issued in March 1974. NIST Monograph 175 is provided by the United States Department of Commerce, National Institute of Standards and Technology.
  • Page 102 Thermocouple Descriptions the purity of commercial type B materials that are used in many industrial thermometry applications that meet the calibration tolerances described later in this section. Both thermoelements will typically have significant impurities of elements such as palladium, iridium, iron, and silicon [38]. Studies by Ehringer [39], Walker et al.

  • Page 103: Type E Thermocouples

    Thermocouple Descriptions 1100°C, an additional measurement error of 3µV (about 0.3°C) would be insignificant in most instances. ASTM Standard E230-87 in the 1992 Annual Book of ASTM Standards [7] specifies that the initial calibration tolerances for type B commercial thermocouples be ±0.5 percent between 870°C and 1700°C.
  • Page 104 Thermocouple Descriptions Type E thermocouples are recommended by the ASTM [5] for use in the temperature range from -200°C to 900°C in oxidizing or inert atmospheres. If used for extended times in air above 500°C, heavy gauge wires are recommended because the oxidation rate is rapid at elevated temperatures.

  • Page 105: Type J Thermocouples

    Thermocouple Descriptions may not satisfy the tolerances specified for the -200°C to 0°C range. If materials are required to meet the tolerances below 0°C, this should be specified when they are purchased. The suggested upper temperature limit, 870°C, given in the ASTM standard [7] for protected type E thermocouples applies to AWG 8 (3.25 mm) wire.
  • Page 106 Thermocouple Descriptions emphasized that type JN thermoelements are NOT generally interchangeable with type TN (or EN) thermoelements, although they are all referred to as “constantan”. In order to provide some differentiation in nomenclature, type JN is often referred to as SAMA constantan.

  • Page 107: Type K Thermocouples

    Thermocouple Descriptions The suggested upper temperature limit of 760°C given in the above ASTM standard [7] for protected type J thermocouples applies to AWG 8 (3.25 mm) wire. For smaller diameter wires the suggested upper temperature limit decreases to 590°C for AWG 14 (1.63 mm), 480°C for AWG 20 (0.81 mm), 370°C for AWG 24 or 28 (0.51 mm or 0.33 mm), and 320°C for AWG 30 (0.25 mm).
  • Page 108 Thermocouple Descriptions When oxidation occurs it normally leads to a gradual increase in the thermoelectric voltage with time. The magnitude of the change in the thermoelectric voltage and the physical life of the thermocouple will depend upon such factors as the temperature, the time at temperature, the diameter of the thermoelements and the conditions of use.

  • Page 109: Type N Thermocouples

    Thermocouple Descriptions Type N Thermocouples This section describes Nickel-Chromium-Silicon Alloy Versus Nickel-Silicon-Magnesium Alloy thermocouples, commonly referred to as type N thermocouples. This type is the newest of the letter-designated thermocouples. It offers higher thermoelectric stability in air above 1000°C and better air-oxidation resistance than types E, J, and K thermocouples.
  • Page 110 C-10 Thermocouple Descriptions calibration. In addition, their use in atmospheres with low, but not negligible, oxygen content is not recommended, since it can lead to changes in calibration due to the preferential oxidation of chromium in the positive thermoelement. Nevertheless, Wang and Starr [49] studied the performances of type N thermocouples in reducing atmospheres, as well as in stagnant air, at temperatures in the 870°C to 1180°C range and found them to be markedly more stable...

  • Page 111: Type R Thermocouples

    Thermocouple Descriptions C-11 one-half the standard tolerances given above. Tolerances are not specified for type N thermocouples below 0°C. The suggested upper temperature limit of 1260°C given in the ASTM standard [7] for protected type N thermocouples applies to AWG 8 (3.25 mm) wire.

  • Page 112: Type S Thermocouples

    C-12 Thermocouple Descriptions Szaniszlo [24], and Walker et al [25,26] have determined the effects that prolonged exposure at elevated temperatures (>1200°C) in vacuum, air, and argon atmospheres have on the thermoelectric voltages of type R thermocouples. ASTM Standard E230-87 in the 1992 Annual Book of ASTM Standards [7] specifies that the initial calibration tolerances for type R commercial thermocouples be ±1.5°C or ±0.25 percent (whichever is greater) between 0°C and 1450°C.
  • Page 113 Thermocouple Descriptions C-13 Research [27] demonstrated that type S thermocouples can be used from -50°C to the platinum melting-point temperature. They may be used intermittently at temperatures up to the platinum melting point and continuously up to about 1300°C with only small changes in their calibrations.

  • Page 114: Type T Thermocouples

    C-14 Thermocouple Descriptions and physical inhomogeneities in the thermocouple and thereby limit its accuracy in this range. They emphasized the important of annealing techniques. The positive thermoelement is unstable in a thermal neutron flux because the rhodium converts to palladium. The negative thermoelement is relatively stable to neutron transmutation.
  • Page 115 Thermocouple Descriptions C-15 family of copper-nickel alloys containing anywhere from 45 to 60 percent copper. These alloys also typically contain small percentages of cobalt, manganese and iron, as well as trace impurities of other elements such as carbon, magnesium, silicon, etc. The constantan for type T thermocouples usually contains about 55 percent copper, 45 percent nickel, and small but thermoelectrically significant...
  • Page 116 C-16 Thermocouple Descriptions heating in air at 500°C. At this temperature the type TN thermoelements have good resistance to oxidation and exhibit only small voltage changes heated in air for long periods of time, as shown by the studies of Dahl [11]. Higher operating temperatures, up to at least 800°C, are possible in inert atmospheres where the deterioration of the type TP thermoelement is no longer a problem.

  • Page 117: References

    Thermocouple Descriptions C-17 References [1] Preston-Thomas, H. The International Temperature Scale of 1990 (ITS-90). Metrologia 27, 3-10; 1990. ibid. p. 107. [2] The International Practical Temperature Scale of 1968, Amended Edition of 1975. Metrologia 12, 7-17, 1976. [3] Mangum, B. W.; Furukawa, G. T. Guidelines for realizing the International Temperature Scale of 1990 (ITS-90).
  • Page 118 C-18 Thermocouple Descriptions Vol. 5, Schooley, J. F., ed.; New York: American Institute of Physics; 1982. 1159-1166. [14] Potts, J. F. Jr.; McElroy, D. L. The effects of cold working, heat treatment, and oxidation on the thermal emf of nickel-base thermoelements.
  • Page 119 Thermocouple Descriptions C-19 Temperature: Its Measurement and Control in Science and Industry; Vol. 6; Schooley, J. F., ed.; New York: American Institute of Physics; 1992. 559-564. [24] Glawe, G. E.; Szaniszlo, A. J. Long-term drift of some noble- and refractory-metal thermocouples at 1600K in air, argon, and vacuum. Temperature: Its Measurement and Control in Science and Industry;...
  • Page 120 C-20 Thermocouple Descriptions [32] McLaren, E. H.; Murdock, E. G. The properties of Pt/PtRh thermocouples for thermometry in the range 0-1100°C: II. Effect of heat treatment on standard thermocouples. National Research Council of Canada Publication APH 2213/NRCC 17408; 1979. [33] McLaren, E. H.; Murdock, E. G. Properties of some noble and base metal thermocouples at fixed points in the range 0-1100°C.
  • Page 121 Thermocouple Descriptions C-21 [44] Burley, N. A.; Powell, R. L.; Burns, G. W.; Scroger, M. G. The nicrosil versus nisil thermocouple: properties and thermoelectric reference data. Natl. Bur. Stand. (U.S.) Monogr. 161; 1978 April. 167p. [45] Burley, N. A.; Jones, T. P. Practical performance of nicrosil-nisil thermocouples.
  • Page 122 C-22 Thermocouple Descriptions [54] Burley, N. A. N-CLAD-N: A novel advanced type N integrally-sheathed thermocouple of ultra-high thermoelectric stability. High Temperatures- High Pressures 8, 609-616; 1986. [55] Burley, N. A. A novel advanced type N integrally-sheathed thermocouple of ultra-high thermoelectric stability. Thermal and Temperature Measurement in Science and Industry;...

  • Page 123: Using A Grounded Junction Thermocouple

    Appendix Using Thermocouple Junctions This appendix describes the types of thermocouple junctions available, and explains the trade-offs in using them with the 1762-IT4 thermocouple/mV analog input module. Take care when choosing a thermocouple junction, ATTENTION and connecting it from the environment to the module.

  • Page 124: Using An Ungrounded (Isolated) Junction Thermocouple

    Using Thermocouple Junctions The shield input terminals for a grounded junction thermocouple are connected together and then connected to chassis ground. Use of this thermocouple with an electrically conductive sheath removes the thermocouple signal to chassis ground isolation of the module. In addition, if multiple grounded junction thermocouples are used, the module channel-to-channel isolation is removed, since there is no isolation between signal and sheath (sheaths are tied together).

  • Page 125: Using An Exposed Junction Thermocouple

    Using Thermocouple Junctions Measuring Junction Isolated from Sheath Using an Exposed Junction An exposed junction thermocouple uses a measuring junction that does not have a protective metal sheath. A thermocouple with this Thermocouple junction type provides the fastest response time but leaves thermocouple wires unprotected against corrosive or mechanical damage.
  • Page 126 Using Thermocouple Junctions To prevent violation of channel-to-channel isolation: • For multiple exposed junction thermocouples, do not allow the measuring junctions to make direct contact with electrically conductive process material. • Preferably use a single exposed junction thermocouple with multiple ungrounded junction thermocouples. •...

  • Page 127: Module Addressing

    Appendix Module Configuration Using MicroLogix 1200 and RSLogix 500 This appendix examines the 1762-IT4 module’s addressing scheme and describes module configuration using RSLogix 500 and a MicroLogix 1200 controller. Module Addressing The following memory map shows the input image table for the module.

  • Page 128: 1762-It4 Configuration File

    RSLogix 500 Version 5.50 or software, assumes your module is installed as expansion I/O in a Higher MicroLogix 1200 system, and that RSLinx™ is properly configured and a communications link has been established between the MicroLogix processor and RSLogix 500.
  • Page 129 Module Configuration Using MicroLogix 1200 and RSLogix 500 Start RSLogix and create a MicroLogix 1200 application. The following screen appears: While offline, double-click on the IO Configuration icon under the controller folder and the following IO Configuration screen appears. This screen allows you to manually enter expansion modules into expansion slots, or to automatically read the configuration of the controller.
  • Page 130 Module Configuration Using MicroLogix 1200 and RSLogix 500 A communications dialog appears, identifying the current communications configuration so that you can verify the target controller. If the communication settings are correct, click on Read IO Config. The actual I/O configuration is displayed. In this case, it matches our manual configuration.
  • Page 131 Module Configuration Using MicroLogix 1200 and RSLogix 500 The 1762-IT4 module is installed in slot 1. To configure the module, double-click on the module/slot. The general configuration screen appears. Configuration options for channels 0 to 2 are located on a separate tab from channel 3, as shown below.

  • Page 132: Generic Extra Data Configuration

    Module Configuration Using MicroLogix 1200 and RSLogix 500 The Cal tab contains a check box for disabling cyclic calibration. See Selecting Enable/Disable Cyclic Calibration (Word 4, Bit 0) on page 3-14 for more information. Generic Extra Data Configuration This tab redisplays the configuration information entered on the 1762-IT4 configuration screen in raw data format.

  • Page 133: Configuration Using Rslogix 500 Version 5.2 Or Lower

    Module Configuration Using MicroLogix 1200 and RSLogix 500 Configuration Using If you do not have version 5.5 or higher of RSLogix 500, you can still configure your module, using the Generic Extra Data Configuration RSLogix 500 Version 5.2 or dialog.
  • Page 134 Module Configuration Using MicroLogix 1200 and RSLogix 500 Publication 1762-UM002A-EN-P - July 2002...

  • Page 135: Glossary

    Glossary The following terms and abbreviations are used throughout this manual. For definitions of terms not listed here refer to Allen-Bradley’s Industrial Automation Glossary, Publication AG-7.1. A/D Converter– Refers to the analog to digital converter inherent to the module. The converter produces a digital value whose magnitude is proportional to the magnitude of an analog input signal.
  • Page 136 Glossary cut-off frequency – The frequency at which the input signal is attenuated 3 dB by a digital filter. Frequency components of the input signal that are below the cut-off frequency are passed with under 3 dB of attenuation for low-pass filters. data word –...
  • Page 137 Glossary is expressed in percent full-scale input. See the variation from the straight line due to linearity error (exaggerated) in the example below. Actual Transfer Function Ideal Transfer LSB – Least significant bit. The LSB represents the smallest value within a string of bits. For analog modules, 16-bit, two’s complement binary codes are used in the I/O image.
  • Page 138 Glossary sampling time – The time required by the A/D converter to sample an input channel. status word – Contains status information about the channel’s current configuration and operational state. You can use this information in your ladder program to determine whether the channel data word is valid.
  • Page 139 Index Numerics common mode rejection 3-11 definition G-1 -3 dB frequency 3-12 specification A-2 common mode rejection ratio definition G-1 specification A-2 definition G-1 common mode voltage abbreviations G-1 definition G-1 accuracy A-4 common mode voltage range vs temperature and filter frequency A-5– definition G-1 A-22 specification A-2...
  • Page 140 Index extended error information field 4-5 input module status general status bits 3-2 over-range flag bits 3-3 under-range flag bits 3-3 fault condition input type/range selection 3-8 at power-up 1-4 installation filter grounding 2-8 definition G-2 heat and noise considerations 2-4 filter frequency International Temperature Scale 1990 C-1 definition G-2...
  • Page 141 Index overall accuracy two’s complement binary numbers B-1 definition G-3 type B over-range flag bits 3-3 accuracy A-5–A-6 description C-1 effective resolution 3-15–3-16 temperature range 1-1 positive decimal values B-1 type C power-up diagnostics 4-3 accuracy A-7–A-8 power-up sequence 1-4 effective resolution 3-17–3-18 program alteration 4-2 temperature range 1-1...
  • Page 142 Index under-range flag bits 3-3 wiring 2-1 update time 3-33 modules 2-11 update time. See channel update time. routing considerations 2-4 update time. See module update time. Publication 1762-UM002A-EN-P - July 2002...
  • Page 143 AB Parts...
  • Page 144 Publication 1762-UM002A-EN-P - July 2002 Copyright © 2002 Rockwell Automation. All rights reserved. Printed in the U.S.A.

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