Allen-Bradley 1771-IXHR Thermocouple/mV Input Module

Allen-Bradley 1771-IXHR PLC-5 High-Resolution Thermocouple/mV Input Module is an eight-channel analog input module designed for PLC-5 systems. It accepts thermocouple and millivolt signals and provides high-resolution measurement suitable for precise temperature monitoring and small-signal sensing in industrial environments. The module is designed to plug into a 1771 I/O chassis and delivers input data words to the PLC processor’s data table and configuration words via block transfer programming, enabling efficient data movement within PLC-5 programs. Each of the eight channels can be configured for thermocouple input ranges or millivolt inputs, offering flexible multi-sensor temperature monitoring and low-level signal acquisition. As part of the 1771 PLC-5 I/O family, the IXHR is a legacy, high-resolution thermocouple/mV input option, and it was officially discontinued on May 31, 2017, with engineering replacement guidance provided by Rockwell Automation. This module is intended for legacy installations and is typically used in process temperature monitoring across multiple sensing points, or for precise mV measurements in instrumentation signals that require finer resolution than standard analog inputs. Installation notes document the high-resolution thermocouple/millivolt input and its connection diagram within the PLC-5 1771 I/O ecosystem.