FUNCTION_BLOCK PID_control
VAR_INPUT
	ProcesVal		:INT;		(*proceswaarde*)
	SetVal			:LREAL;		(*wenswaarde*)
	Auto			:BOOL;		(*als true dan automatisch regelen*)
	Direct			:BOOL;		(*als true dan direct acting, oftewel: verwarmen of koelen *)
	TimeBase		:LREAL;		(*moet 1000 of groter zijn*)
	Gain			:LREAL;		(* Kp *)
	ResetRate		:LREAL;		(* Tr  *)
	Derivative		:LREAL;		(* Td *)
END_VAR
VAR_OUTPUT
	ControllerOut		:LREAL;		(* output *)
END_VAR
VAR
	testbit			: BOOL;
	TON_pulstijd		: TON;
	TON_pauzetijd		: TON;
	Puls			: R_TRIG;
	Err			: LREAL;
	ErrLast			: LREAL;
	ErrlastLast		: LREAL;
	ControllerOutTemp	: LREAL;
END_VAR



testbit := TRUE;

(*		cyclustijd PID regeling*)
TON_pulstijd (in := NOT ton_pauzetijd.Q, PT := LREAL_TO_TIME(Timebase - 500));
TON_pauzetijd (in := ton_pulstijd.Q, PT := t#500ms);
Puls (clk := TON_pulstijd.Q);

(*		PID regeling*)
IF
	Puls.Q
THEN
	IF	(*---------------------------------------------------------------------auto mode*)
		 auto
	THEN
		Err := SetVal - ProcesVal;

		IF 		(*------------------------direct mode*)
			NOT direct
		THEN
			Err := 0 - Err;
		END_IF	(*-----------------------------------------*)
               
                (*de PID zelf: *)
                ControllerOutTemp := ControllerOut + (Gain * ( Err - ErrLast + (ResetRate * Err) + (Derivative * ( Err -(ErrLast *2) + errlastLast))));
		ControllerOut := ControllerOutTemp; (*alleen voor controle, verder is het niet nodig dit via een kladvariabele te doen*)

		ErrLastLast := ErrLast;
		ErrLast := Err;
	ELSE
		ControllerOut := 0;
		ErrLastLast := Err;
		ErrLast := Err;


	END_IF	(*-------------------------------------------------------------------------------*)
END_IF

IF
	ControllerOut > 100
	AND auto
THEN
	ControllerOut := 100;
END_IF

IF
	ControllerOut < 0
	OR NOT auto
THEN
	ControllerOut := 0;
END_IF