The first thing to realize is that you posted to the wrong board. Measure is an old NI product - an Excel add-on.Post to the Multifunction DAQ board.
In you code, you are not setting the infput configuration - i.e. differential, single-ended, etc. Provide details on your connections from the power supply to the DAQ device and look at the recomended connections in the manual. You also need to provide details on what you mean by 'they are not the same'. Is the difference volts, millivolts, or what?
