Multichannel data acquisition problem with DAQPad 6015

[RAGHUL]

I am giving two inputs for DAQPad 6015 , inputs are from a function generator. When the channels are sampled individually they are fine but when done simultaneously then the data read is not proper. Three pictures are attached one picture showing channel one data, next picture showing channel two waveform and third picture showing both channel one and channel two as seen in the test panels of the Measurement and automation explorer. The same problem exists when viewed with a labview program.

[WM_John_Weeks]

It looks like the red line is a combination of both signals. That might happen if you have connected the signals to just one half of a differential input.

If you are using differential inputs, you need to connect the signal plus to the pin for AI0 and the signal minus to the pin for AI8.

Alternately, connect signal plus to AI0 and signal minus to AI ground, but make sure to select RSE inputs (Referenced Single-Ended).

[Tom_W_[DE]]

Hi All-

John's suggestion seems to be right on the money- it seems like the second signal is just being superimposed over the first.  For differential inputs on the DAQpad-6015 on channel 0 you will need to connect your positive signal pin to ai0 (pin 1) and your negative signal pin to ai8 (pin 2).  For differential channel 1 you will need to use ai1 (pin 4) and ai9 (pin5) for positive and negative signal pins, respectively.

Let us know if you're still seeing problems-