The Allen-Bradley 1771-IXHR is a PLC 5 Analog Input Module. It is a high-resolution thermocouple/millivolt input module to transfer input data words from its memory to the PLC processor’s data table and transfer configuration words using block transfer programming. The 1771-IXHR requires a single-slot for installation in a 1771 I/O chassis and needs no external power supply.

The 1771-IXHR module has 8 floating differential inputs for thermocouple or millivolt input ranges which includes types B, E, J, K, T, R, and S thermocouples and ±100 millivolts. Either 8 of the same type of inputs are allowed or 4 inputs each of 2 different types. The 1771-IXHR includes cold junction compensation with a range of 0-60°C and ±0.5°C accuracy. It has a selectable temperature scale of °C or °F with a temperature resolution of 0.1°C or 0.1°F and millivolt resolution of 1µV. It requires a backplane current load of 750mA at 5V and has a channel update time of 25ms per 8 channels. Its wiring is connected to the 1771-WI field wiring arm eliminating the need for disconnecting the wires when replacing the module. The 1771-IXHR has a maximum power dissipation of 4.255W and maximum thermal dissipation of 14.5 BTU/hr. Keying bands must be put between pins 20-22 and pins 24-26 to accept only this module.

The 1771-IXHR module has high and low-temperature alarms that are selectable by the user. It contains a green RUN indicator and a red FLT indicator at the front panel for power and fault status. At power-up, it performs self-diagnostics and reports status. The 1771-IXHR provides open-circuit detection in case the thermocouple fails. It automatically calibrates offset and gain for each channel, eliminating the need of potentiometers.