TP

Pulse timer. Generates a pulse of duration PT on the rising edge of input IN.

IEC 61131-3	Section 2.5.2.3.3
Support	Supported

Inputs

Name	Type	Description
IN	BOOL	Triggers a pulse on each rising edge. Changes during the pulse have no effect.
PT	TIME	Pulse duration. The pulse always runs for this full duration once triggered.

Outputs

Name	Type	Description
Q	BOOL	TRUE while a pulse is active. Becomes FALSE when ET reaches PT.
ET	TIME	Elapsed time since the pulse started. Holds at PT after the pulse completes.

Behavior

When IN transitions from FALSE to TRUE (rising edge), the output Q becomes TRUE and the elapsed time ET begins counting from T#0s. The output Q remains TRUE until ET reaches the preset time PT, at which point Q becomes FALSE. Changes to IN during the pulse have no effect; the pulse always runs for the full duration PT.

Example

This example triggers a 1-second pulse. On the first scan IN is TRUE, so the pulse starts and active becomes TRUE.

Try it

Source

PROGRAM main
   VAR
      pulse : TP;
      active : BOOL;
      elapsed : TIME;
   END_VAR

   pulse(IN := TRUE, PT := T#1s, Q => active, ET => elapsed);
   (* After first scan: active = TRUE, pulse is running *)
END_PROGRAM

See Also

• TON — on-delay timer

• TOF — off-delay timer