Missing triggers on PCI 6052E

[ponnaboy]

Erin,
I have problem with a DAQ vi which does triggered acquisition with pre-trigger scans.The problem is that it misses some of the triggers even for a modest triggering rate.These triggers are generated mechanically by hitting a strain guage,the o/p of which is send thru a transducer and a Coulbourn discriminator producing a TTL pulse.I'm using a PCI6052E DAQ card.Total # of scans = 1000,scan rate = 10000,pre-trigger scans=400.

[Ben]

Hi Shiv,

Do thing work corrctly for the first trigger and then miss subsequent triggers?

When you say "modest triggering rate" are you talking faster than 10 time a second?

If yes, it may be that the your app is busy updating screens or similar and does not get back around to starting another I/O before the following triggers occur.

I hope this helps,

Ben

[ponnaboy]

It misses triggers in a random fashion.I am manually triggering it...that may be like 2 or 3 triggers per second.
Thanks,
Shiva

[Ben]

Hi shiv,

It has been a while since I looked your code but if I remember correctly, the structure had you doing some data collection and then updating a display. I suspect the triggers are getting missed while the app is doing other things.

To avoid this situation I would advise you restructure the app such that there is one loop doing the the data collection, and another to handle anything else that is required.

Ben

[Filipe A.]

Hello;

Agree with Ben's answer and would like to add one extra comment. Make sure the trigger signal you are generating externally, meet all the requirements for a signal to be a valid trigger signal (refer to the documentation of your DAQ board).
Hope this helps.
Filipe