Choosing Between Rising and Falling Edge for Trigger

[Vlngrl87]

I am collecting data from a photodetector using LabVIEW and want to trigger the aquisition of waveforms using an external pulse generator.  This pulse generator is also used to trigger another piece of equipment, and the whole set-up is very time sensitive.  Does it matter if I set it to trigger using rising or falling edges, and if so, which would be best for this application?

[Steve_B]

Hi VIngrl87,

You can use either edge for triggering purposes, but the once that will best suit your application depends on the signal itself and the configuration of your other hardware that is triggering. Do you want the devices to trigger at the same time or offset by the pulse width?

[kikiduu]

I would suggest you use the same triggering edge that you are using for the all the other equipments that you trigger with this external pulse. BTW what is this external pulse input and does it signify some event? If yes what type of event?

[Vlngrl87]

I want the two to trigger at the same time.

Thanks.

[Vlngrl87]

The pulse is coming from a pulse generator, and the spacing is based on some physical characteristics of our sample that we're measuring.