the TCU Controller accepts signals from a variety of temperature sensors (thermocouple or RTD elements), precisely displays the process temperature, and provides an accurate output control signal (time proportional or linear) to maintain a process at the desired control point. A comprehensive set of easy to use steps allows the controller to solve various application requirements. the controller can operate in the PID control mode for both heating and cooling, with on-demand auto-tune, which will establish the tuning constants. the PID tuning constants may be fine-tuned by the operator at any time and then locked out from further modification. the controller employs a unique overshoot suppression feature, which allows the quickest response without excessive overshoot. the unit can be transferred to operate in the manual mode, providing the operator with direct control of the output. the controller may also be programmed to operate in the ON/OFF control mode with adjustable hysteresis. dual 4-digit displays allow viewing of the process temperature and setpoint simultaneously. front panel indicators inform the operator of the controller and output status. Replaceable and interchangeable output modules (relay, SSR drive, or triac) can be installed for the main control output, alarm output(s) and cooling output.