I am trying to read three channels of the USB 6215 board with Labview DAQmx. Two Channels are connected to photodiodes and one to a stepper motor sending his position in volt.
The problem is that as soon as I read all three channels I got an offset due to the signal from the stepper motor on the photodiode channels.
If I only read one channel without changing the connections, this cross channel talking does not appear.
I am using differential coupling for all three channels and the ground of all three devices is connected to the ground of the USB 6215 Board.
If somebody have an idea would be great.
