FUNCTION_BLOCK FB_Measure_Pulse
VAR_INPUT
	Signal :BOOL;//Signal A (Rising / Falling Edge detection)
END_VAR
VAR_OUTPUT
	Delta :TIME;//Time measured
END_VAR
VAR
	Sample_On : TIME;//Time Sampled when Signal is on
	Sample_Off : TIME;//Time Sampled when signal is off
	Edge_On : BOOL;//Edge Trigger (Rising)
	Edge_Off : BOOL;//Edge Trigger (Falling)
END_VAR
		

code:

IF Signal AND (NOT Edge_On) THEN //Rising Edge of signal
	Sample_On := TIME();
	//Edge_On := TRUE;
	Edge_On  := TRUE ;
	Edge_Off := FALSE;
END_IF;
	

IF (NOT Signal) AND (NOT Edge_Off) THEN
	Sample_Off := TIME();
	//Edge_Off := TRUE;	
	Edge_Off := TRUE;
END_IF;


IF (Edge_On AND Edge_Off) THEN
	//Delta := TIME_TO_DINT(Change of output format , to your use);
	Delta := Sample_Off - Sample_On;  //Value in time format
	Edge_On  := FALSE;

END_IF;