I agree that a pattern match is probably your best bet. You can setup the trigger, start the acquistion, call "wait until done" and after you return from it, you know that a poulse has arrived and you can proceed with generation.
Just FYI: if you happen to have a 653x card laying around; these boards have a "Change detection" timing mode which works at relatively slower speeds, but would be the ticket for this type of application.
Good luck with your project.
Juan Carlos
