OMRON CJ1W‑TC001 – Thermocouple Temperature Control Unit for CJ1 PLC

The OMRON CJ1W-TC001 is a dedicated temperature control module designed for the CJ1 series programmable logic controllers. It provides two independent control loops with thermocouple inputs, featuring advanced PID autotuning and heating/cooling output options. This module is essential for applications requiring accurate temperature regulation in industrial processes.

Input and Sensor Support

The CJ1W-TC001 accepts thermocouple types K, J, T, E, L, U, N, R, S, and B, covering a wide range of temperature measurements from -200 °C to 1800 °C depending on the sensor. Each of the two channels is isolated and has cold junction compensation, ensuring high accuracy even in varying ambient conditions. The input impedance is greater than 1 MΩ, and the module has a resolution of 0.1 °C for most thermocouple types.

Control Outputs

Each channel provides two output signals: one for heating (control output) and one for cooling (auxiliary output). The outputs can be configured as ON/OFF, PID, or heating/cooling PID with deadband. Outputs are typically 24 V DC transistor outputs, but can also drive solid‑state relays or contactors via external interposing relays. The module supports both standard and reversed action for heating and cooling applications.

PID and Autotuning

The CJ1W-TC001 features a sophisticated PID algorithm with automatic tuning (AT) to determine optimal proportional, integral, and derivative constants for the process. Users can also manually set PID parameters or select from preset patterns. The module includes feed‑forward control and limiting functions to prevent overshoot. The control cycle time is adjustable from 0.5 to 99.9 seconds, allowing adaptation to different thermal time constants.

Alarm and Event Functions

Built‑in alarm functions include absolute high/low, deviation high/low, and rate‑of‑change alarms. Each channel can have up to four alarm setpoints, with hysteresis adjustable to avoid nuisance tripping. Alarms can be latched or non‑latched, and their status is reflected in the PLC’s I/O memory for integration into the main control logic.

Integration with CJ1 PLC

The module connects to the CJ1 backplane and is mapped into the PLC’s memory as a Special I/O Unit. Configuration is done via CX‑Programmer’s I/O table or using dedicated FB (function blocks) for temperature control. The module supports data exchange with the CPU for setpoint changes, readback of process value, and error handling, ensuring seamless coordination with the overall machine program.

Installation and Diagnostics

DIN rail mounting and front‑accessible terminal blocks simplify wiring. LED indicators on the module display power, run, and error status for each channel. Internal diagnostics include sensor break detection, short‑circuit detection, and cold junction failure alerts. The module stores error history for troubleshooting.

Environmental and Certification

Operating temperature range is 0 °C to 55 °C, with humidity 10% to 90% non‑condensing. The CJ1W-TC001 is CE and UL listed, and complies with EMC directives for industrial environments.

Applications

This temperature control unit is widely used in plastic injection molding, extrusion, heat treatment furnaces, packaging sealing bars, and HVAC systems. Its dual‑channel capability allows independent control of two zones, saving space and cost compared to separate controllers.

In conclusion, the OMRON CJ1W-TC001 provides precise, reliable temperature control with flexible configuration, making it a valuable addition to any CJ1‑based automation system.