PID

PID controller with anti-windup mechanism and manually controllable output.

Input

Name	Type	Description
ACTUAL	REAL	Measured process variable
SET_POINT	REAL	Set point
KP	REAL	Proportional gain factor
TN	REAL	Integral time
TV	REAL	Derivative time
Y_MANUAL	REAL	Sets the control signal Y manually while ignoring any offset, if MANUAL is TRUE
Y_OFFSET	REAL	Offsets the control signal Y
Y_MIN	REAL	Lower limit of the control signal Y
Y_MAX	REAL	Upper limit of the control signal Y
RESET	BOOL	TRUE resets the integrator to zero and sets the control signal Y to Y_OFFSET
MANUAL	BOOL	TRUE resets the integrator to zero and enables setting the control signal Y manually

Output

Name	Type	Description
Y	REAL	Control signal
LIMITS_ACTIVE	BOOL	TRUE, IF (Y ≥ Y_MAX) OR (Y ≤ Y_MIN)

Functional description

The ideal standard form of the PID controller is given by:

, where

Integral windup can be prevented by setting the limits of the control signal. Once the control signal reaches the limits, the integrator is stopped at its current value.