interference signals with NI 9206.

[UTC-Aerospace]

Hello everyone,
So I use NI input/output modules for acquisition of signals on DasyLab, including a 9206 module for voltage acquisition.
It turns out that I have noisy signals with great noise pikes from time to time.
Knowing that we bought the NI hardware for its noise isolation, would there be a better way to use the hardware?
Or a configuration on NI MAX or use the digital filters on DasyLab to guard against interference signals?
Thank you.

[CJ_Butler__DASYLab_Pro]

The first place to deal with noisy signals is at the source. Once the noise has been digitized, it can distort your signal and may be difficult to remove. 

Check for ground loops and ensure that you have grounded the signal correctly. Use shield wiring, whenever possible, and keep your wiring as short as possible. Frequencies higher than your sample rate may cause aliasing in the signal. 

NI.com has a number of articles about how to correctly connect your signal. The choice of single ended vs differential is an important decision. At Measurement Computing, we have a Guide to Signal Connections https://www.mccdaq.com/support/DAQ-Signal-Connections.aspx that addresses these issues. 

Once acquired, I would recommend that you run an FFT to see if the noise is at a specific frequency. If so, you may be able to use an analog filter circuit or an anti-aliasing filter to remove it. 60 cycle interference is common, as well as interference from nearby equipment. The best place to remove noise is before the signal is digitized.

If the noise is truly "spikes" and grounding does not resolve it, then look at the Slope Limitation module. It damps the rate of change. 

Of course, the Digital Filter and Average modules can also be used to try to eliminate noise. All three of these techniques will affect your signal.

[UTC-Aerospace]

Thanks Cj,
I will try to apply what you have told me and see how it evolves.
Thankyou.