Why don't i get any value reading from index array

[M.PEDERSEN]

Hi, 

I trying to build my first VI and struckleíng with getting a numeral value from my reading, just give NaN as output, but my chart works fine. 

What am I doing wrong?

[SabariSaravanan.M]

Until give index value to index array it'll give output as 0th index values. Check row0 whether its having values or not.

[GerdW]

Hi M.,

you get a mean of NaN when the "subarray" is empty. Simple as that.

• When reading "N chan N samples" from DAQMxRead you should provide a number of samples to read.
• You should check the error out of DAQmxRead - already inside the loop.
• Notice that error number found in your "Selftest" list? It has a meaning, explained easily by using an error indicator and its context menu. Read that explanation…
• Why are there 4 DAQmx channel controls? Why not use just one control and select several channels with it?

[johntrich1971]

Your chart must have some old data. You need to tell the DAQmx Read how many data points that you want to read. Currently you are getting an empty array - and that's why you're getting the NaN.

Edited to note that GerdW beat me to the punch.