Decimation and E-prime triggers

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Decimation and E-prime triggers

Post by Sam » Wed Apr 23, 2014 5:06 am


I have a question about decimation affecting the triggers being send through e-prime. When I don't use decimation (i.e decimation: 1) I don't have any problems, but when I want to down sample the triggers change. The triggers changed both when I used decimation with speed mode 5 (when sample rate is 4096) and with speed mode 4 (when sample rate is 2048). It doesnt seem to be the sampling rate itself, since both 4096 Hz and 2048 Hz work fine if I don't use decimation. I added a .jpg to clarify the change.

Thanks in advance,
triggerprob.jpg (230.89 KiB) Viewed 6176 times

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Re: Decimation and E-prime triggers

Post by Coen » Wed Apr 23, 2014 11:41 am

During decimation, an OR function is applied to the individual trigger bits within a group of samples. So, do not use decimation when the time between triggers is less than the sample time of the decimated sample rate.

Best regards, Coen (BioSemi)

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