Pulse duration measurement of a single, non-periodic pulse

[Joesph]

New to Labview. I'm trying to measure pulse duration of a single, Power- On-Reset, pulse using waveform data. The Pulse measurements VI requires two consecutive mid ref level crossings in the same direction. I have only one positive going mid ref level crossings & one negative in the waveform data. Am I missing something easy in the Waveform Measurements palette or do I need to use counters to accomplish this task? I would like to use waveform data. 

Labview 8.6 Professional. 

[chilly_charly]

You could use the Transition measurement.vi twice, as shown on the attachment.

Message Edité par chilly charly le 09-01-2008 07:04 PM

[Joesph]

Thanks CC.

[tomdeb]

Hi chilly_charly,

I've tried your VI on my laptop and it works fine.

I also wants to measure the duration of a single pulse, I've tried your solution but the result isn't correct : 476ns instead of something like 120ns (approximately measured on the graph).... The result of the start time is also strange ; it is equal to 3510146181.02804184s for the fall time and 3510146181.02804232s for the rise time instead of 200ns and 320ns respectively. 

In attachment, you'll find my VI where I also measure the rise time which is correct (8ns) so it quiet strange that the start time appears like that. The waveform comes from an acquisition on a NI-Scope, I've set the default values so that I can work on this waveform without the scope.

Thanks for your help,

Thomas