Slow graph update: 6070E vs. 6024E

[carfo]

I have a VI that continously acquires two signals, saves the data (as binary I16) and displays it on a graph. When I run this VI using a DAQpad 6070E with sampling rate = 30 kHz and scans to read at a time = 3000, everything works fine. But when I run the VI using a DAQcard-6024E with sampling rate = 1 kHz and scans to read at a time = 100, the graph updating becomes very slow. It takes up to 4 seconds for the graph to update. Is this what to expect from a 6024E device? The maximum sampling rate of this card is 200 kS/s.

Can anybody please explain why there is such a difference in performance when using a 6070E device compared to using a 6024E device? It seems that a lot more cpu is needed when I use the 6024E-card. Are there any manuals or application notes about this?

Thanks,
Carina

[devchander]

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But when I run the VI using a DAQcard-6024E with sampling rate = 1 kHz and scans to read at a time = 100, the graph updating becomes very slow. It takes up to 4 seconds for the graph to update. Is this what to expect from a 6024E device? The maximum sampling rate of this card is 200 kS/s.

Can anybody please explain why there is such a difference in performance when using a 6070E device compared to using a 6024E device? It seems that a lot more cpu is needed when I use the 6024E-card. Are there any manuals or application notes about this?

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Your DAQ card might be working just fine ( verify it with giving Sampling rate= Scans to read)

The "graph updating becomes very slow" problem might have a very different reason and nothing to do with the acquisition capabilities of your card.

One of the reasons  for this slow update might be because you are trying to update it 10 times every sec ( sampling rate = 1 kHz and scans to read at a time = 100, will make the while loop for continuous acq run 10 times in a sec)

Are you using a graph or a chart??

[carfo]

Thank you for your answer.

I am using a chart (or actually two charts, one for each signal). The charts can be updated 10 times every second when I use the 6070E device (sampling rate = 30 kHz, scans to read at a time = 3000), but when I use the 6024E-card the maximum update rate seems to be about once or twice a second.

[devchander]

could you attach your vi which has this behaviour??