With continuous data sampling with DAQMX, error -200279 occurs while attaining 2d dbl array

[Dennis_Knutson]

No, it is not. Multiplexed switching has nothing to do with your problem, as I already said.

It sounds like you fixed the problem by just switching off continuous mode. You could have done the same thing without resorting to a sequence structure.

[azurenight17]

If you say so, please take a look. I'll be glad if there would be a way to fix it. Thank you.

[Dennis_Knutson]

You've got hidden code in express Vis. Remove all of that processing and try it.

Have you tried an unmodified example yet?

[azurenight17]

That I don't know. Would you explain what is hidden code and where to find, please?

And unmodified VI examples don't fit with the circuit I'm using, so the result in LabView isn't correct. Thank you.

[Dennis_Knutson]

I already told you where the hidden code was and the whole point of running an example is to see if you get an error. The actual data after your processing is as irrelevant as some of your other statements.

[moderator1983]

In your original code just remove START function (the one with Green play button symbol) and then try running your code... The issue could be, as you have a triggering setup, this code will wait for that specific trigger to happen before starting reading the samples (from device to software). But when you choose to START the task the acquisition of samples starts and it starts filling the CIRCULAR BUFFER..Even in this situation your code is waiting for Trigger to happen and as soon as the specified Trigger event happens, 'DAQmx Read.vi' tries to read overwritten samples (at CIRCULAR BUFFER) and throws an error...

You might want to check this... I don't have hardware so can run your code only with SIMULATED device.

[azurenight17]

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@moderator1983 wrote:

In your original code just remove START function (the one with Green play button symbol) and then try running your code... The issue could be, as you have a triggering setup, this code will wait for that specific trigger to happen before starting reading the samples (from device to software). But when you choose to START the task the acquisition of samples starts and it starts filling the CIRCULAR BUFFER..Even in this situation your code is waiting for Trigger to happen and as soon as the specified Trigger event happens, 'DAQmx Read.vi' tries to read overwritten samples (at CIRCULAR BUFFER) and throws an error...

You might want to check this... I don't have hardware so can run your code only with SIMULATED device.

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I've tried as you adviced, but it won't work for me. I think I should adjust my system for DAQ to sample properly.

Thank you for your concern.

[azurenight17]

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@0utlaw wrote:

Hello Azurenight,

The 6259 is a multiplexed M-series DAQ card, meaning that it isn't possible to sample each signal at the same instant, rather the channels are all sent through the same ADC and must be sampled in order. More information on this can be found here:

LabVIEW Help: Multiplexed Versus Simultaneous Sampling

http://zone.ni.com/reference/en-XX/help/370466W-01/mxcncpts/multisimulsamp/

It might still be possible to get the data you need with the card you have- could you provide more information on the maximum allowable delay between samples on different channels?

If you need *actual* simultaneous sampling, you'll likely need different hardware.

Regards,

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I've fixed the error based on Tom's advice. My DAQ could not sample all four signals instantly,

so I adjusted my circuit to provide the output signals a bit longer and to send the trigger signal by a wide margin.

As my DAQ was able to take enough time for multiplexed sampling, the data were acquired properly.

Thank you.