Table of Contents

CTUD

Block name

CTUD

ST call

PROGRAM CTUD_DEMO
   VAR
     BOOL1,BOOL2,BOOL3,BOOL4,BOOL5,BOOL6: BOOL;
  INT1,INT2: INT;
     FB:CTUD;
   END_VAR
    FB(CU:=BOOL1,CD:=BOOL2,R:=BOOL3,LD:=BOOL4,PV:=INT1,QU=>BOOL5,QD=>BOOL6,CV=>INT2);
END_PROGRAM

Description

The block is an up and down counter. If both r and ld are true, r has higher priority.

Inputs

InputTypeDescription Default value
CU BOOLAdds 1 on rising edge False
CD BOOLSubtracts 1 on rising edge False
R BOOLReset to zero False
LD BOOLSets the counter to the maximum valueFalse
PV INT Maximum counter value 0

Outputs

OutputTypeDescription
QU BOOLStatus when the counter reaches its maximum value
QD BOOLStatus when the counter is zero
CV INT Current counter value

Application example