I have a requirement to measure 3 phase input voltages on the cDAQ-9184. If I were to measure only 1 channel at a time, the result measurement is correct at 115VAC on each of the 3 phases. If we were to measure multiple channels simulatanously, then the first channel is measured correctly at 115VAC (phase A), the other two channels have a output less than the first channel. 109VAC (Phase B) and 108VAC (Phase C) respectively. If we were to measure the other two channels seperately or the second and third channel. The output would be ok on the first channel measured (Phase B 115VAC) and the second channel would be less voltage.(Phase C 109VAC). I am unable to determine why the measurement error is there between the three channels. when confirmed its able to measure each channel independently correctly?
NI Hardware: cDAQ-9184 device
I have attached a screen shot of the VI in use and the code below also, Labview 2016, Windows 7 OS.