TP / TP_S - Pulse

This timer function block creates a pulse.

If the input IN changes from FALSE to TRUE, a pulse is created at output Q for the time interval set at the input PT. The elapsed time while Q=TRUE is output at ET. If IN becomes TRUE for a second time before the time set at PT has elapsed, Q remains unchanged.

The function block is available as standard function block TP and safety-related function block TP_S.

Parameter	Data types	Description
IN	BOOL	If a rising edge is detected, a pulse is created.
PT	TIME	Preset time interval for the pulse
Q	BOOL	TRUE if IN = TRUE and ET < PT. FALSE if IN = FALSE and ET >= PT.
ET	TIME	Elapsed time interval

TP_S

Parameter	Data types	Description
IN	SAFEBOOL	If a rising edge is detected, a pulse is created.
PT	SAFETIME	Preset time interval for the pulse
Q	SAFEBOOL	TRUE if IN = TRUE and ET < PT. FALSE if IN = FALSE and ET >= PT.
ET	SAFETIME	Elapsed time interval

NOTE:

Function blocks have to be instantiated. Like variables, instances have to be declared before they can be inserted in a code body. Instances must be unique within the POU. In the following example, the instance name 'PULSE_TIMER' is used for the TP_S FB.

Timing diagram

Example for safety-related function block declaration TP_S

Variables declarations in this example

NOTE:

If you want to use the standard function block TP in your code worksheet, you have to select the data type 'TP' for the function block instance in the local variables worksheet. Accordingly, the data types 'BOOL' and 'TIME' must be used instead of 'SAFEBOOL' and 'SAFETIME'.