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Error -200431 occurred at DAQmx Create Channel (AI-Voltage-RMS)

Using Labview 2015 Base. 

 

I am trying to measure the Voltage RMS from a USB-6001 analog input channel.  When executing, I get the message shown further below.  In the error message, it shows possible values without any option for "voltage rms" listed.  What is happening here?  Any help is appreciated. 

 

Capture.JPG

 

Error -200431 occurred at DAQmx Create Channel (AI-Voltage-RMS).vi:4330001

Possible reason(s):

Selected physical channel does not support the measurement type required by the virtual channel you are creating.

 

Create a channel of a measurement type that is supported by the physical channel, or select a physical channel that supports the measurement type.

 

Property: AI.MeasType

Requested Value: Voltage RMS

Possible Values: Current, Resistance, Strain Gage, Temperature:Built-in Sensor, Temperature:RTD, Temperature:Thermistor, Temperature:Thermocouple, Voltage, More:Voltage:Custom with Excitation 

Task Name: _unnamedTask<47>

 

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Voltage RMS is the kind of measurement a multimeter device would take where it measures over a period of time and takes an RMS average.  A regular DAQ device takes voltage at a point of time.  What you want to do is collect a multiple samples of "voltage".  Preferably complete cycles.  Then take an RMS value of the waveform that is collected.

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Hey, thanks for the comment.  So my original  overview of my measurement environment was incomplete.  Added is the section where I am trying to calculate the RMS value of 1000 samples.  The issue, as stated, still remains. 

 

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I don't see where you are taking an RMS on the array of data coming from the DAQmx Read.

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An interesting point. 

 

If I was working with the Labview Full, I believe the programming sequence would be:

  • DAQmx Create Virtual Channel, set to 'AI Voltage'  (or 'AI Voltage RMS'?)
  • DAQmx Read, set to 'Analog 1D DBL 1Chan NSample' with a count of 1000
  • Use the RMS VI, from the Probability & Stats pkg, to calculate my desired reading

I assume that this is a properly executed measurement.  Specifically, I do not have to choose the 'AI Voltage RMS' polymorphic when creating the Virtual Channel in order to have the RMS VI work properly.  All true?  (Maybe this is a misunderstanding on my part.)

 

So, I do not have Labview Full.  I have Labview Base.  I do not have the Probability & Stats Pkg.  I could calculate the RMS value manually, but I THOUGHT THE 'AI Voltage RMS' polymorphic provided me the feature of generating an RMS value per my code snippet.  

 

If I try to use the RMS VI, I get a fail message stating one of the possible reasons as not being licensed for the Stats pkg.  If I use the 'AI Voltage RMS' selection, the error message does not provide any indication of a missing [Stats] pkg. 

 

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