Rockwell Automation Allen-Bradley 1794-IT8 User Manual
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Rockwell Automation Allen-Bradley 1794-IT8 User Manual

Rockwell Automation Allen-Bradley 1794-IT8 User Manual

Flex i/o thermocouple/millivolt input module
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FLEX I/O Thermocouple/Millivolt
Input Module
Catalog Number 1794-IT8
User Manual
Original Instructions

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Summary of Contents for Rockwell Automation Allen-Bradley 1794-IT8

  • Page 1 FLEX I/O Thermocouple/Millivolt Input Module Catalog Number 1794-IT8 User Manual Original Instructions...

  • Page 2: Important User Information

    If this equipment is used in a manner not specified by the manufacturer, the protection provided by the equipment may be impaired. 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.

  • Page 3: Table Of Contents

    Calibrate Your Module for a ControlNet or an EtherNet/IP Network... . 29 Use DeviceNetManager Software to Calibrate Your Module ..... . 35 Rockwell Automation Publication 1794-UM007B-EN-P - August 2024...
  • Page 4 ..............47 Rockwell Automation Publication 1794-UM007B-EN-P - August 2024...

  • Page 5: Preface

    Industrial Automation Wiring and Grounding Guidelines, publication 1770-4.1 Provides general guidelines for installing a Rockwell Automation industrial system. Product Certifications website, rok.auto/certifications Provides declarations of conformity, certificates, and other certification details.
  • Page 6 Preface Notes: Rockwell Automation Publication 1794-UM007B-EN-P - August 2024...

  • Page 7: Overview Of Flex I/O System

    These instructions let the adapter obtain input or output values and status from the module, and let you establish the modules mode of operation. Figure 2 shows the typical communication process. Rockwell Automation Publication 1794-UM007B-EN-P - August 2024...

  • Page 8: Features Of Your Module

    The current draw through the terminal base determines the wiring of the terminal base unit. Verify that the current draw does not exceed 10 A. ATTENTION: Total current draw through the terminal base unit is limited to 10 A. Separate power connections may be necessary. Rockwell Automation Publication 1794-UM007B-EN-P - August 2024...
  • Page 9 24V DC All modules that are powered by the same power supply must be analog modules in this configuration. The total current draw through any base unit must not be greater than 10 A. Rockwell Automation Publication 1794-UM007B-EN-P - August 2024...
  • Page 10 Chapter 1 Overview of FLEX I/O System and Thermocouple/mV Module Notes: Rockwell Automation Publication 1794-UM007B-EN-P - August 2024...

  • Page 11: Program Your Module

    The same block transfer control file is used for both the read and write instructions for your module. A different block transfer control file is required for every module. A sample program segment with block transfer instructions is shown in Figure 4, and described as follows: Rockwell Automation Publication 1794-UM007B-EN-P - August 2024...

  • Page 12: Plc-5 Programming

    CONTROL: N13:20 DATA FILE: LENGTH: CONTINUOUS: PLC-2 Programming The FLEX I/O analog modules are not recommended for use with PLC-2® family programmable controllers due to the number of digits needed for high resolution. Rockwell Automation Publication 1794-UM007B-EN-P - August 2024...

  • Page 13: Write Configuration To Your

    0…2315 °C (32…4199 °F) 0…23150 (320…41990) 0.1 °C (0.1 °F) Type E –270…+1000 °C (-454…+1832 °F) –2700…+1000 (-4540…+18320) 0.1 °C (0.1 °F) Type J –210…+1200 °C (-346…+2192 °F) –2100…+12000 (-3460…+21920) 0.1 °C (0.1 °F) Rockwell Automation Publication 1794-UM007B-EN-P - August 2024...

  • Page 14: Hardware First Notch Filter

    The module uses up to 11 words of input Modules image and up to 3 words of output image. Each word is composed of 16 bits. Rockwell Automation Publication 1794-UM007B-EN-P - August 2024...
  • Page 15 Write Word 2 Thermocouple 7 Type Thermocouple 6 Type Thermocouple 5 Type Thermocouple 4 Type CK = Calibration clock CH = Calibration high Where: CL = Calibration low FDF = Fixed digit filter bit Rockwell Automation Publication 1794-UM007B-EN-P - August 2024...
  • Page 16 Calibration mask – The channel or channels to be calibrated have the correct mask bit set. The bit 8 corresponds to the 08…15 (10…17) channel 0, bit 9 corresponds to the channel 1, and so on. Rockwell Automation Publication 1794-UM007B-EN-P - August 2024...
  • Page 17 Channel 5 Thermocouple Type (see write word 1, bits 00…03) Write Word 2 08…11 (10…13) Channel 6 Thermocouple Type (see write word 1, bits 00…03) 12…15 (14…17) Channel 7 Thermocouple Type (see write word 1, bits 00…03) Rockwell Automation Publication 1794-UM007B-EN-P - August 2024...
  • Page 18 Chapter 3 Write Configuration to Your Module and Read Status from Your Module with a Remote I/O Adapter Notes: Rockwell Automation Publication 1794-UM007B-EN-P - August 2024...

  • Page 19: Communication And I/O Image

    I/O Module Fault bits – 1 status bit for each slot • Node Address Changed bit – 1 bit • I/O State bit– 1 bit I/O Module Fault bits Bit: 10...15 Not Used I/O State bit Node Address Changed bit Rockwell Automation Publication 1794-UM007B-EN-P - August 2024...

  • Page 20: System Throughput

    The selection influences the A/D output data rate, thus affecting system throughput. The number of channels included in each input scan also affects system throughput. Mapping Data into the The FLEX I/O thermocouple module data table mapping is shown in Figure Image Table Rockwell Automation Publication 1794-UM007B-EN-P - August 2024...
  • Page 21 Write Word 2 Thermocouple 7 Type Thermocouple 6 Type Thermocouple 5 Type Thermocouple 4 Type CK = Calibration clock CH = Calibration high Where: CL = Calibration low FDF = Fixed digit filter bit Rockwell Automation Publication 1794-UM007B-EN-P - August 2024...
  • Page 22 Calibration mask – The channel or channels to be calibrated have the correct mask bit set. The bit 8 corresponds to the 08…15 (10…17) channel 0, bit 9 corresponds to the channel 1, and so on. Rockwell Automation Publication 1794-UM007B-EN-P - August 2024...

  • Page 23: Defaults

    You can reduce the write words to 0, thus eliminating the configuration setting and unused words. And you can reduce the read words to 10 by eliminating the calibration status words. Rockwell Automation Publication 1794-UM007B-EN-P - August 2024...
  • Page 24 Chapter 4 Communication and I/O Image Table Mapping with the DeviceNet Adapter Notes: Rockwell Automation Publication 1794-UM007B-EN-P - August 2024...

  • Page 25: Calibrate Your Module

    If you use a sensor other than a thermocouple, disconnect the lead wires at the sensor and tie together for this measurement. Reconnect after measurement. d. After measurement, remove the ohmmeter. Rockwell Automation Publication 1794-UM007B-EN-P - August 2024...

  • Page 26: Manually Calibrate Your Module

    To let the internal temperature of the module stabilize, energize the module for at least 40 minutes before you start calibration. Module calibration consists of: • Applying a reference voltage to the desired inputs Rockwell Automation Publication 1794-UM007B-EN-P - August 2024...
  • Page 27 BTW = Block transfer write BTR = Block transfer read CB = Calibration bad CD = Calibration done CR = Calibration range CD = 1 CK = Calibration clock CH = Calibration high CL = Calibration low Rockwell Automation Publication 1794-UM007B-EN-P - August 2024...
  • Page 28 CK = Calibration clock CB = Calibration bad CH = Calibration high Where: CD = Calibration done CL = Calibration low CR = Calibration range FDF = Fixed digit filter bit BS = Bad structure Rockwell Automation Publication 1794-UM007B-EN-P - August 2024...

  • Page 29: Calibrate Your Module For A Controlnet Or An Ethernet/Ip Network

    During calibration the module stores the calibration data for two set points referred to as offset and gain. The offset calibration is taken with input 0.000 mV and the gain calibration is done with 75.000 mV. Rockwell Automation Publication 1794-UM007B-EN-P - August 2024...
  • Page 30 CalibrationOutOfRange = 0 Set CalibrationClock = 0 Set CalibrationClock = 0 GainOffsetCalibration = 0 CalibrationDone = 0 CalibrationDone = 0 Clear the corresponding bits in the calibration mask. Legend: MR = Module reconfigure Rockwell Automation Publication 1794-UM007B-EN-P - August 2024...
  • Page 31 +24V DC Power Terminals 34, 35, 50, and 51 For 1794-TB3: Terminals 34…51 (1) Terminals 36, 37, 38 and 47, 48, 49 are cold junction compensator connections. (2) Terminals 39…46 are chassis ground. Rockwell Automation Publication 1794-UM007B-EN-P - August 2024...
  • Page 32 3. Right-click on the tag name given in the Message Control field and declare it as a New MR_msg. 4. Select the button next to MR_msg. The Message Configuration - MR_msg dialog appears. 5. From the Message Type dropdown list, select Module Reconfigure. 6. Select Communication tab. Rockwell Automation Publication 1794-UM007B-EN-P - August 2024...
  • Page 33 If CalibrationMaskChN is 1, this channel (Channel N) is calibrated. If CalibrationMaskChN is 0, this channel (Channel N) is not calibrated. 4. Set the GainOffsetCalibration bit to 0 and send a ModuleReconfigure. Rockwell Automation Publication 1794-UM007B-EN-P - August 2024...
  • Page 34 10. If individually calibrating the channels, perform the Step 1…Step 8 again for offset calibration on any additional channels that you want to calibrate. 11. Set all CalibrationMaskChN bits to 0. Send a ModuleReconfigure. Rockwell Automation Publication 1794-UM007B-EN-P - August 2024...

  • Page 35: Use Devicenetmanager Software To Calibrate Your Module

    3. Select the Slot, which contains your thermocouple module in Module Configuration. For example, in the following screen, the thermocouple input module is in Slot 0. You must select Slot 0. The following dialog appears: 4. Select Calibration... to get to the calibration screen. Rockwell Automation Publication 1794-UM007B-EN-P - August 2024...

  • Page 36: Gain Calibration

    2. Under Channel Selection, select the checkboxes for channels that you want to calibrate. 3. Under Channel Type, select the Gain Calibration option. Then select Start Calibration. 4. When calibration is complete, you see a notification indicating Gain Calibration Successful in the Calibration Status area. Rockwell Automation Publication 1794-UM007B-EN-P - August 2024...
  • Page 37 Configuration screen. Select Save to Flex I/O or Save to File... to save the configuration. If you attempt to close without saving your configuration information by selecting the Close option, you are prompted to save the changes. Select Yes to continue. Rockwell Automation Publication 1794-UM007B-EN-P - August 2024...
  • Page 38 Chapter 5 Calibrate Your Module Notes: Rockwell Automation Publication 1794-UM007B-EN-P - August 2024...

  • Page 39: Resolution Curves, Worst Case

    0.20 46.08 11.52 2.88 0.36 12.80 3.20 0.80 0.10 23.04 5.76 1.44 0.18 –300 1200 1650 –150 1050 1350 1500 1800 –508 1652 –238 1112 1382 1922 2192 2462 2732 3002 3272 Temperature Rockwell Automation Publication 1794-UM007B-EN-P - August 2024...

  • Page 40: Type C Thermocouple

    0.30 69.12 17.28 4.32 0.54 25.60 12.80 1.60 0.20 46.08 11.52 2.88 0.36 12.80 6.40 0.80 0.10 23.04 5.76 1.44 0.18 –300 –150 1050 1200 –508 1112 1382 1652 –238 1922 2192 Temperature Rockwell Automation Publication 1794-UM007B-EN-P - August 2024...

  • Page 41: Type J Thermocouple

    1.080 51.20 12.80 3.200 0.400 92.16 23.04 5.760 0.720 25.60 6.400 1.600 0.200 46.08 11.52 2.880 0.360 1350 1050 1200 1500 –300 –150 1652 2192 2462 1382 1922 2732 –508 –238 1112 Temperature Rockwell Automation Publication 1794-UM007B-EN-P - August 2024...

  • Page 42: Type L Thermocouple

    34.56 8.64 1.08 51.20 12.80 3.20 0.40 92.16 23.04 5.76 0.72 25.60 6.40 1.60 0.20 46.08 11.52 2.88 0.36 –150 –300 1200 1350 1050 –238 –508 1112 1382 1652 2462 1922 2192 Temperature Rockwell Automation Publication 1794-UM007B-EN-P - August 2024...

  • Page 43: Type R Thermocouple

    0.20 46.08 11.52 2.88 0.36 12.80 3.20 0.80 0.10 23.04 5.76 1.44 0.18 –300 –150 1050 1200 1350 1500 1800 1650 –508 1652 1922 2462 –238 1112 1382 2192 2732 3002 3272 Temperature Rockwell Automation Publication 1794-UM007B-EN-P - August 2024...

  • Page 44: Type T Thermocouple

    Table 15 - Error Due to Open Circuit Current Through Loop Resistance Resistance Error per Ω of Loop Resistance Input Type (°C) (°F) 0.091 0.164 0.013 0.023 0.016 0.029 0.024 0.043 0.076 0.137 0.083 0.149 0.022 0.040 0.028 0.050 Rockwell Automation Publication 1794-UM007B-EN-P - August 2024...

  • Page 45: Worst Case Repeatability For The Thermocouple/Mv Input Module

    ±0.34 ±0.61 ±0.68 ±1.22 ±0.13 ±0.23 ±0.26 ±0.46 ±0.19 ±0.30 ±0.37 ±0.62 ±12 µV ±12 µV ±24 µV/°C ±24 µV/°F Note: The filter is enabled by setting bit 02 in write word 0. Rockwell Automation Publication 1794-UM007B-EN-P - August 2024...
  • Page 46 Appendix A Resolution Curves, Worst Case Accuracy, Error Due to Open Circuit Current, and Worst Case Repeatability Notes: Rockwell Automation Publication 1794-UM007B-EN-P - August 2024...

  • Page 47: Index

    27 throughput, normal mode 14 I/O module fault 20 wiring connections 28 input ranges 13 input scaling 13 input status word 19 mapping, 1794-IT8 14 module fault 20 module features 8 Rockwell Automation Publication 1794-UM007B-EN-P - August 2024...
  • Page 48 Index Notes: Rockwell Automation Publication 1794-UM007B-EN-P - August 2024...
  • Page 49 FLEX I/O Thermocouple/Millivolt Input Module User Manual Rockwell Automation Publication 1794-UM007B-EN-P - August 2024...

  • Page 50: Rockwell Automation Support

    At the end of life, this equipment should be collected separately from any unsorted municipal waste. Rockwell Automation maintains current product environmental compliance information on its website at rok.auto/pec. Allen-Bradley, DeviceNetManager, expanding human possibility, FactoryTalk, FLEX, FLEX I/O-XT, PLC-2, PLC-3, PLC-5, Rockwell Automation, Studio 5000 Logix Designer, and TechConnect are trademarks of Rockwell Automation, Inc.

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