Trigger saving glitch

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noxid
Posts: 2
Joined: Thu Jul 15, 2010 12:43 pm
Location: Switzerland

Trigger saving glitch

Post by noxid » Thu Jul 15, 2010 12:55 pm

Hello,

I've recorded some data with triggers (10ms) that were sent by an other computer (via the USB box) and they only appear in your BDFreader and no other software.

I used a third computer to retest the recording and this time the triggers were visible in my other readers. Can lag of a computer mess up the writing of the triggers (my computers are heating up a lot due to their location in a closed backpack)? Is it possible to manually resave the data from your BDFreader?

Thanks

Alex

Coen
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Post by Coen » Thu Jul 15, 2010 1:23 pm

If the BDFreader shows triggers, then there are triggers saved in the BDF file. If other readers do not show theses trigger (sometimes), then there is a problem with these other readers.

Best regards, Coen

noxid
Posts: 2
Joined: Thu Jul 15, 2010 12:43 pm
Location: Switzerland

Post by noxid » Tue Jul 20, 2010 2:15 pm

Hello again,

I've done some further testing and it would seem that if I launch my trigger sequence before I start actiview and then launch the recording my triggers in any reader are fine. If I start recording before my trigger sequence it defaults to 8 bit triggers in all alternate software readers and misses the higher ones. I am using triggers 1-4 and 9-10 in this experiment. 9-10 are ignored in the later scenario.

Coen
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Post by Coen » Tue Jul 20, 2010 3:18 pm

Use positive trigger logic (High = trigger, Low = idle), return all trigger lines to Low after a trigger, and keep unused trigger lines Low (either by your trigger software, or by a hard wire connection to ground, pin 37), length of trigger pulse should be longer than 1 sample period.

Best regards, Coen (BioSemi)

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