I am measuring mV on 8 channels using 2 NI 9239's and want to find the mean of each channel

[dh2o]

I'm using 2 NI 9239's to capture the voltages at 8 point on a test fixture. The voltages are very small (a few mV). I want to take an average of 1k samples from each channel and use these to calculate the resistivity of the sample under test. 

What is the easiest method to precisely measure 8 channels?

[crossrulz]

Let's start from the beginning.  Do you know how to read 1k samples from 8 channels using a single DAQmx Task?  Once you have that, then use a FOR loop to do a mean on each channel's data.

[dh2o]

So, I need to set up a for loop with a loop count equal to the number of samples for each channel. 

[Dennis_Knutson]

No, the loop count should equal the number of channels. If you are passing a 1D waveform array. You just have to pass in the array to the for loop and it will be auto-indexed. No need to wire anything to the n terminal.