Data adquisition.

[Gada]

Good Afternoon, everyone.

I have a question, I am doing a program for data acquisition, I have the Cdaq9174 and NI 9230 cards, when I connect the accelerometers IMI 603c01, a frequency of 60 Hz appears, I ask the question of why this signal appears with a frequency of 60 Hz In addition to that, the signal is not centered, I do not know if that is normal, the questions are:

Does anyone know the cause why this 60 Hz signal appears?

How can the influence of this signal be mitigated or eliminated?

How can I center the signal of the perceived noise. Annex the images of the signals that appear in the program.

If you know anything about it, or where you could investigate, read etc, I would appreciate it.

[Bob_Schor]

60 Hz is probably the frequency of your AC circuitry (unless you are in those parts of the world where it is 50 Hz).  If you have a lot of 60 Hz "noise", this suggests a bad connection, an unshielded connection, or an "incorrect" connection (single-ended when it should be differential, differential when it should be single-ended, not properly grounded, etc.).

The reason for the DC offset of the "noise" is that it may be riding on your Accelerometer signal.  Try turning the Accelerometer upside-down -- does the noisy signal move?

There are numerous sources on the Web discussing signals and grounding.  One from NI is here.  

Bob Schor