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`
Output	`CV`	`WORD`	Current counter value