Example - Manual - SIMATIC AX - Counter function blocks. - System.Counters,library

USING System.Counters;

PROGRAM SampleProgram
    VAR_EXTERNAL
        pushButton : BOOL;
        switch : BOOL;
        light : BOOL;
    END_VAR
    VAR
        count : Counter := (presetValue := 10);
    END_VAR
    VAR_TEMP
        total : INT;
    END_VAR

    // increment counter by 1 for every push of the button
    count(up := pushButton, down := switch);

    // pushButton created a rising edge 10 times more often than switch
    IF count.presetReached THEN
        light := true;
    END_IF;

    IF count.value > 100 THEN
        count(reset := true); // reset the current value to 0
        count(reset := false); // set reset to false, otherwise the count will stay 0 regardless of other inputs
    END_IF;

END_PROGRAM