Using external clock on a 6062E DAQ card

[E.G.]

In my application I need to use an external clock (2 MHZ) to sample 10 channels at 40 KHz each. I connected the external clock to PFI_7/Startscan, enabled the ND_IN_CHANNEL_CLOCK_TIMEBASE and ND_IN_SCAN_CLOCK_TIMEBASE using The Select_signal function. If I use only two channels (instead of 10) everything works fine. If I try to increase the number of channels to more than 2 I get a digitized waveform with points missing (one every 2). I tried to decrease the sampling rate to 4 KHz per channel, but the problem persisted. For 2 channels everything is always fine, but for more than 2 I get the same error in the digitization pattern.

The relevant lines of my codes are attached

Thank you for your help

Enrico Gratt
on

[Spencer S.]

Enrico,

I have a couple of questions. Do you see the same amount of missing data regardless of how many channels (more than 2) you are acquiring? If you use the internal 20 MHz timebase, can you successfully acquire all 10 channels at 40 kHz?

Spencer S.

[E.G.]

Dear Spencer

Thank you for your answer. I changed the interrupt flag from automatic to at half_the_buffer and now everything works fine. I have no idea why this fixed the problem.