A PID controller, uses 3 term PID control to control the process. Modification of these parameters is called 'loop tuning'. In order for control of the process to be attained you must enter the correct parameters in these settings this is called Tuning the process. The ControlMaster features an Autotune functionality which can be used to automatically calculate the required PID values. If in the very rare event the autotune is unable to tune the process, you will find in the ControlMaster manual a selection of PID values which can be used as a starting point for tuning standard application types.