1771-IXHR

Product Overview

1771-IXHR is an Allen-Bradley high-resolution thermocouple/millivolt input module designed for precise temperature and millivolt measurements in PLC-3 and PLC-5 systems.

Module Identity

• Model: 1771-IXHR

• Product Type: Thermocouple/Millivolt Input Module

• Class: Programmable Logic Controller Module

• Manufacturer: Allen-Bradley Rockwell

• Number of Channels: 8 points

• Resolution: High

Input Specifications

• Number of Inputs: 8 (all same type) or 4 each of 2 different types

• Thermocouple Linearization: IPTS-68 standard, NBS MN-125

• Cold Junction Compensation Range: 0…60 °C

• Accuracy: ±0.5 °C

• Temperature Scale: Selectable °C or °F

• Input Resolution: 3.2328 µV

• Display Resolution: 0.1 °C, 0.1 °F; or 1.0 µV, 10 µV

Electrical & Isolation Characteristics

• Input Isolation: 1000 V peak (between inputs, input to common, input to backplane)

• Common Mode Rejection: 120 dB at 60 Hz, up to 1000 V peak

• Common Mode Impedance: >10 MΩ

• Normal Mode Rejection: 60 dB at 60 Hz over +100 mV

• Input Overvoltage Protection: 120 V rms continuous

• Open Input Detection: Overrange in <10 seconds

Connections & Data

• Input Connections: 18-terminal wiring arm (Cat. No. 1771-WI)

• Data Format: 2’s complement binary

Calibration

• Auto Calibration: Offset and gain

• Manual Calibration: Zero offset and gain adjustment per channel via programming terminal

• Verification: Every six months recommended for maintaining accuracy

Compatibility

• I/O Chassis Location: Any single I/O module slot

• Processor Compatibility: PLC-3 or PLC-5 family processors using 1771 I/O structure and block transfer

• Note: Not recommended for PLC-2 family processors

Environmental Ratings

• Operating Temperature: 0…60 °C (32…140 °F)

• Rate of Change: Ambient changes >0.5 °C/min may temporarily degrade performance

• Storage Temperature: -40…85 °C (-40…185 °F)

• Relative Humidity: 5…95% (non-condensing)

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