I am determining if my setup produces DC analog voltages at undesired times. I want to leverage my DAQ hardware AI to monitor AO tasks running a separate VI, but I am stuck at what I think of as step zero.
I have an NI PCIe-6353 board connected to a BNC-2110. As a sanity check, I connected a BNC cable from AO0 to AI0 and used the DAQmx example code to Voltage Continuous out and Input vi to try and drive a sin (or triangle wave) on the output and read it back on the input. I assumed this would be straightforward, forward, and I would read back whatever I drove. But instead, I get a noisy signal. Playing with the terminal config in RSE/NRSE I get a constant 5.29 volts. Switching to differentially, I get a signal that slowly trends to about 3.1V with a really noisy version of the output wave overlayed on the noise, with output of +/-5V, the input signal has a peak-to-peak 0.03V signal. I get similar results when I drive a triangle, square, or sawtooth wave; the noise has a super-faint signal. Max gives the same kind of results.
To make my problem even more difficult, this hardware is five time zones away, and I have very limited local/hands-on troubleshooting support.
What am I doing wrong? Should connecting a BNC cable between AO0 and AI0 allow me to spy on my output signals? I am 99% sure that the DAQ output equipment is functional. I was previously driving some other hardware with it and getting reasonable interactions with the other device. I think my local support merely disconnected the old BNC cable from AO0 and installed a loopback instead.
Thanks
