PID Response Graph

The graph above shows how the response of PID controller can change based on the set coefficients. In this example, the system is subjected to a setpoint change. The controller with K = 0.5 reacts rather slowly and reaches the setpoint with no overshoot. This condition is referred to as overdamped. The controller with K = 1.6 reacts extremely fast and severely overshoots the setpoint. The controller adjusts accordingly so that the output eventually settles down at the setpoint. This condition is referred to as underdamped. Finally, the controller with K = 1.1 reaches the setpoint quickly with minimal overshoot. Each PID controller application is different than the next and the coefficients need to be adjusted appropriately to achieve the desired response.