1771-IXHR | Allen Bradley | PLC 5 High-Resolution Thermocouple/Millivolt Input Module

Product Overview

The Allen Bradley 1771-IXHR provides high-precision temperature and millivolt sensing for legacy PLC-5 control systems. This module interfaces directly with various thermocouple types and millivolt sources, converting low-level analog signals into high-resolution digital data. We supply this unit as 100% Brand New original stock, featuring a factory-applied conformal coating to ensure long-term stability in corrosive or high-humidity industrial atmospheres.

Technical Specifications

The 1771-IXHR utilizes a high-speed backplane interface to deliver precise thermal telemetry across eight channels.

Engineering Advantages

• Ultra-Fast Thermal Response: With a channel update rate of 25 ms for all eight inputs, the 1771-IXHR captures rapid temperature fluctuations that standard analog modules might miss. This speed enables tighter PID control loops in high-precision heat treatment and chemical reaction processes.

• Floating Differential Inputs: The module employs eight floating differential inputs to reject common-mode noise. This architecture prevents ground loops and electrical interference from distorting sensitive millivolt signals, even in environments with heavy motor switching or high-frequency induction.

• Corrosion Resistance: The factory conformal coating protects internal circuitry against airborne contaminants, moisture, and chemical vapors. This hardware hardening makes the 1771-IXHR an ideal choice for wastewater treatment, oil and gas, and pulp and paper facilities.

• High-Resolution Accuracy: The 15-bit plus sign resolution ensures precise data conversion, translating to 1.0 degree per bit. This granularity allows the PLC-5 processor to make minute adjustments to fuel-to-air ratios or cooling valves, maximizing energy efficiency and product consistency.

FAQs

• What thermocouple types does the 1771-IXHR support?

  The module supports a wide array of industrial standards, including Type B, E, J, K, R, S, and T thermocouples. It also accepts direct $\pm$99.99 mV signals for non-standard sensing applications.

• Does this module require an external power supply for the field side?

  No. The 1771-IXHR draws its required 750 mA operating current directly from the 1771 backplane. This reduces wiring complexity and saves space in the remote I/O chassis or local rack.

• Can I hot-swap this module during operation?

  While the 1771 chassis supports "Removal and Insertion Under Power" (RIUP), you must exercise caution to prevent system glitches. Always verify that your PLC-5 program handles I/O faults gracefully before removing the module from a live backplane.

• Why should I choose the "IXHR" version over standard thermocouple modules?

  The "IXHR" variant offers significantly higher resolution (15-bit) and faster update times compared to standard 1771-IX units. Furthermore, the standard conformal coating provides an extra layer of protection for legacy systems operating in harsh or aging facilities.