What is the reset function of a controller also known as?

The reset function of a controller, also referred to as the integral action, serves a crucial purpose in control systems. This function is designed to eliminate steady-state error that may occur when a system reaches its desired setpoint. The integral component accumulates the error over time, enabling the controller to adjust the control output to reach and maintain the desired setpoint.

When a difference between the setpoint and the process variable persists, the integral action builds up until the error is corrected, effectively pushing the system to the setpoint. This is particularly important in processes where an immediate correction is necessary for steady-state accuracy. The integral effect helps in minimizing the offset and ensuring that the system remains at the desired operational level over time, contributing to overall stability and performance.

While other concepts like derivative action or feedback are integral to control theory, they serve different functions within a control loop. Derivative action anticipates future errors based on the rate of change of the process variable, while feedback is the mechanism by which the output is used to influence the input. Gain adjustment refers specifically to scaling the output response of the controller and does not directly pertain to the reset function.