Any new benchmarls on 6062E buffered counting?

[halsbane]

Hello,
I am trying to get a laptop (Toshiba Satellite 1100-S101, 1.33 GHz Celeron, 256 MB RAM) to do buffered event counting using a DAQCard-6062E. My measurement parameters using GPCTR0 include a TTL signal coming in on the source pin at a variable frequency between 0-1MHz, and a TTL-like signal on the gate pin (waveform from ACH0) telling the counter to dump into the buffer at 1-10 kHz, usually 2 kHz. The gate signal is set before and remains consant during the measurement. I am using finite buffered counting. I do this for 40-70ms out of every 100ms for up to a minute or more, so I have finite buffer sizes ranging from 40 (40 ms at 1 kHz) to 700 (70 ms at 10 kHz). I think I am forced to use interrupts because of it being a 6062E.

Is this too taxing for the laptop and/or 6062E card, because I keep getting the diabolical error -10920?

I have looked at a few knowledgebase articles, particularly 2C69GDQO (http://digital.ni.com/public.nsf/3efedde4322fef19862567740067f3cc/db428a46f345da4986256aa100556876?OpenDocument), and it seems to me they discuss the rates at which a fairly old computer can make buffer writes using DMA or interrupts. The DAQ-STC source pin should be able count TTL pulses at up to 20 MHz, right? and if that 550 MHz PIII is getting 2-3 kHz of buffer writes using interrupts, then why am I getting error -10920 when I try to do it at 2kHz using a faster computer?

Hope you can help, and thanks.

~Dave

[Jarrod_B.]

Hello halsbane,

That is the downside of operations that are "system dependent."  While theoretically, your computer should be able to acquire these buffered values at the same rate or higher, there is no guarantee.  You may have seen it already, but the following KB describes some factors other than CPU clock speed that can affect the rate of buffered counter operations:

Why Do I Get Error -10920 When Doing Buffered Counter Operations?

Also, I'm not sure whether you're programming this application with NI-DAQmx or Traditional NI-DAQ, but in each case, there are some LabVIEW examples that you could look at to make sure you are coding the task efficiently.  For NI-DAQmx, take a look at the example Count Digital Events-Buffered-Continuous-Ext Clk.vi.  For Traditional NI-DAQ, try the example Count Buffered Edges (DAQ-STC).vi.

I hope this information helps!

Best regards,