TOF

VAR_INPUT

VAR_INPUT
    IN : BOOL; (* starts timer with falling edge, resets timer with rising edge *) 
    PT : TIME; (* time to pass, before Q is set *)
END_VAR

VAR_OUTPUT

VAR_OUTPUT
    Q  : BOOL; (* is FALSE, PT seconds after IN had a falling edge *)
    ET : TIME; (* elapsed time *)
END_VAR

When IN is TRUE, Q is TRUE and ET is 0.As soon as IN becomes FALSE, the time will begin to be counted in milliseconds in ET until its value is equal to that of PT. It will then remain constant. Q is FALSE when IN is FALSE and ET is equal to PT. Otherwise it is TRUE. Thus, Q has a falling edge when the time indicated in PT in milliseconds has run out.
Graphic display of TOF behavior over time:

The function TOF requires 15 byte data.

Requirements