How read values from Waveform (DBL) 1d Array and compare it with a double value in Labview

Question

I want to stop my measurement (right side od the VI) when the user defined stop voltage has arrived in the measurement. But I do not know how I can read the voltage value from the waveform (DBL) 1d Array and compare it with the user typed stop voltage? Hope someone can help me with that. I have attached a snippet of my VI. You can use that like a VI in labview

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Answer 1

You can index the 1D waveform array to get the individual elements and then use the 'Get Waveform elements' node from the 'Waveforms' pallet to get the actual value. You would then have to check these against your Stop Value, either by constructing a 1D array of DBL or just picking one element.

Is there a reason you are using the waveform output from the DAQ read vi? If you change this to a double 'DBL' then you can wire this up directly to your <= function. A 1D array of type double could be wired up to a graph if needed (I am guessing the indicator 'Measurement' is a graph).

Answer 2

You can use the Waveform limit tester to check if everything is below your Threashold. Here's a codesample how it works.

Ton