Data Collection Using cDAQ-9174

[202108594@post.au.dk]

Hi

Iam currently usin the NI cDAQ-9174 (an older version it seems) to collect some data using both vibration and audio sensors. To insert my sensors I use the two NI 9232 with BNC which each have 3 channels. Do you know if the channel have any crosstalk and also do you know if the system can messaure the frequency from the power-grids?

Iam messauring vibrations using the NI MAX program where the unit is in volts but regardless of me putting the sensor on the ground or on a machine with fx 50 Hz I get spikes in the fft domain, at 50 Hz. The grid where I take my messaurments provide a frequency of 50 Hz, but I would still assume that there should be a difference when plotting - but there is not..

Iam I just using the hardware wrong or have you heard of this before?

Kind regards

Lukas

[Oli_Wachno]

This ist the TestStand Software forum

https://forums.ni.com/t5/Multifunction-DAQ/bd-p/250

is probably the better place

BTW.... what you are describing sounds a lot like a ground loop

[202108594@post.au.dk]

Thanks for the answer! I both had a ground loop and other issues but it seems to work now.

Kind regards 

Lukas