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Timing and/or bandwith issues with the NI-9237


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Have configured my NI-9237 as an AI bridge, reading in CONTINUOUS with a very low sample rate and SAMPLES at ONE. I'm running on a FAST Dell Precision T7500 with USB to a cDAQ-9178. But I still get warnings of memory overrun due to not being able to read data fast enough. Tried a bunch of other values and none of them work. I rebooted the PC and the cDAQ and still no go. Any ideas?

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I usually start with a NI example, they aren't perfect but they give a nice starting off point. I recommend the "TDMS Logging - Cont Log and Read Data.vi" found here:

<LabVIEW Directory>\examples\DAQmx\Analog In\Measure Voltage.llb\TDMS Logging - Cont Log and Read Data.vi

I'm guessing your problem is the fact that you are doing a single sample read, which takes a very short amount of time, but then in a loop read again, this whole time the AI read task is still running filling up a buffer, and by the time windows requests another single sample, there maybe hundreds of samples waiting to be read. This eventually fills up and you run out of your buffer on the DAQ hardware. To prevent this try to decrease the sample rate, or increasing the number of samples to read. The example above uses 1K samples at 10KHz.

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