CTD (FB)¶

FUNCTION_BLOCK CTD

Decrements a given value

(* Example declaration *)
CTDInst : CTD ;

(* Example in ST *)
CTDInst(CD:= VarBOOL1, LOAD:=VarBOOL2 , PV:= VarWORD1);
VarBOOL3 := CTDInst.Q ;
VarWORD2 := CTDInst.CV;

InOut:

Scope	Name	Type	Comment
Input	CD	BOOL	Rising edge: Decrementing CV by one
	LOAD	BOOL	TRUE: Set CV to the start value PV
	PV	WORD	Start value for decrementing
Output	Q	BOOL	TRUE if CV = 0
	CV	WORD	Current counter value