hardware trigger start AND stop

[NW]

Hello,
I have a ni DAQ PCI-MIO-19E card in my PC.
I would like to do an acquisition using a start AND a stop trigger. I have
tried with the trig A and B but this doesn't do what I want : I want to
start a buffered data acquisition when the signal in trig (say 1) raise
until the trig (say 2) fall.

Thanks for your help.

[Labviewguru]

This should be easy to solve with gating and some fancy triggering.

I would suggest that you build a timing diagram, showing all of your signals. It sounds like you can just gate the acquisition to your trigger signal, but if you want accurate start and stop, and to be able to read the data as it is triggered, you are going to have to get fancy with trigger lines, gates, and perhaps even some digital lines or occurrences.

I have a lot of experience in this realm. If you like, you can either email or post here a very detailed list of what you are doing, and I will try to help more.

Good luck

[bman]

One possible solution would require the use of two counters. The first counter would be set for Simple Event Counting. You would need to set the initial count to 1 and set it to count down and set the output to toggle on the terminal count. Apply your trigger to the source of this counter. After the first pulse, start trigger, comes in, the counter will count down to zero, TC, this will toggle the output high. Then when the second pulse, stop trigger, comes in, the counter will count down to 2^24-1, which is not the terminal count, so the output will toggle back to low. What this basically does is generate a high signal between the start and stop trigger.

You would set up the second counter for pulse train generation and set the frequency to the rate you want
to acquire data. This pulse train will be used as an external clock for the acquistion. Route the output of the first counter to the Gate of this counter. (This can be done internally.) What this will do is generate a pulse train when the output of counter 1 is high. (between the two pulses.)

Brian