Allen Bradley 1771-IXHR Thermocouple Millivolt Input Module

Product Description

The Allen‑Bradley 1771‑IXHR is a high-resolution analog input module designed for PLC‑5 systems, delivering precise thermocouple and millivolt measurements. Engineers rely on this module for accurate temperature monitoring and low-level voltage detection in critical industrial processes. Moreover, its built-in calibration and cold junction compensation ensure reliable readings without requiring manual adjustments. The module integrates seamlessly into existing PLC‑5 racks, providing fast updates suitable for real-time control applications. Its compact design and diagnostic LEDs enhance system reliability and simplify maintenance.

Key Features

• Supports 8 floating differential analog inputs for thermocouples and millivolt signals.

• Compatible with Type B, E, J, K, R, S, and T thermocouples.

• Millivolt input range up to ±100 mV with 1 µV resolution.

• Built-in cold junction compensation, accuracy ±0.5 °C (0–60 °C).

• Automatic offset and gain calibration eliminates potentiometer adjustments.

• Fast update time of 25 ms for all 8 channels.

• Natural binary data format ensures precise integration with PLC-5 logic.

• Diagnostic LEDs indicate module operation and fault conditions.

• Backplane-powered module, no external power required.

• Compatible with 1771-WI wiring arm for safe and uninterrupted field wiring.

Technical Specifications

• Model: 1771‑IXHR

• Module Type: High-Resolution Thermocouple / Millivolt Input

• Manufacturer: Allen-Bradley / Rockwell Automation (USA)

• Input Channels: 8 floating differential

• Supported Inputs: Thermocouples B, E, J, K, R, S, T; ±100 mV millivolt

• Resolution: Temperature 0.1 °C/°F, Millivolt 1 µV

• Cold Junction Compensation: ±0.5 °C (0–60 °C)

• Update Time: 25 ms per 8 channels

• Data Format: Natural binary

• Backplane Current Load: 750 mA @ 5 VDC

• Power Consumption: 4.255 W max; Heat Dissipation 14.5 BTU/hr

• Indicators: Green RUN LED, Red FLT LED

• Diagnostics: Self-test on power-up; open-circuit detection

• Wiring: Compatible with 1771-WI wiring arm

• Mounting: Rack-mountable

• Weight: 0.84 lbs

Typical Applications

• Precision temperature monitoring in chemical or pharmaceutical processes.

• Low-level voltage measurement in laboratory and production systems.

• High-accuracy data acquisition for critical industrial automation controls.

• Integration with PLC-5 systems for real-time process monitoring.

FAQ

Q: Is external power required for the 1771‑IXHR?
A: No, the module operates entirely on backplane power, consuming 750 mA at 5 VDC.

Q: Can it measure multiple thermocouple types simultaneously?
A: Yes, it supports Types B, E, J, K, R, S, and T across all eight channels.

Q: How does the module handle calibration?
A: Automatic offset and gain calibration ensures high accuracy without manual adjustments.

Q: What is the update time for measurements?
A: The module updates all 8 channels every 25 milliseconds, suitable for real-time control.

Q: Is the 1771‑IXHR still available for purchase?
A: It was discontinued on May 31, 2017. Engineering replacements are recommended for new systems.