Table of Contents

CTD

Block name

CTD

ST call

PROGRAM CTD_DEMO
    VAR
     BOOL1,BOOL2,BOOL3: BOOL;
    INT1,INT2: INT;
     FB:CTD;
    END_VAR
    FB(CD:=BOOL1,LD:=BOOL2,PV:=INT1,Q=>BOOL3,CV=>INT2);
END_PROGRAM

Description

The block acts as a counter counting down to zero from the preset value pv.

Inputs

InputTypeDescription Default value
CD BOOLRising edge counts one down False
LD BOOLSets the counter to its initial value pvFalse
PV INT Initial value of the counter 0

Outputs

OutputTypeDescription
Q BOOLState when the counter finished counting (counting finished: q=true).
CV INT Current value of the counter

Application example