Unable to get individual RMS readings for 4 Analog Input voltage channels from DAQ-USB-6001

[dshukla]

Hi Santhosh,

Could you please elaborate on your previous reply.

Also how could I log the 4 RMS values alongside the voltage values in the ".tdms" file ?

Thank you so much!

[GerdW · Accepted solution]

Hi dshukla,

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@dshukla wrote:

Could you please elaborate on your previous reply.

Also how could I log the 4 RMS values alongside the voltage values in the ".tdms" file ?

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When you calculate the RMS value for an array of 4 waveforms then you get an array of 4 RMS values. Sounds reasonable, doesn't it? What else do you expect?

When it is just for displaying purposes: convert that array of 4 elements into a cluster of 4 elements and use a chart to display that cluster…

As you decided to use the TDMS logging built into DAQmx you have no way to access that TDMS file while it is written. You can only add to this file after your DAQ task has finished!

When you create the TDMS file on your own and write to it using TDMSWrite you can easily add your RMS values, either as 2nd group of channels in the TDMS file or as properties of the waveform channel group…