Signal noise for cDAQ 9137 with C series module 9201

[ANichs123]

Hi there,

I have connected an NI 9201 module to my cDAQ 9137 and am receiving an analogue input voltage signal from each of the seven possible empty channels. The signal however has noise to it as seen below from my NI MAX 'test panels' window.

I have a few questions due to my lack of understanding of this signal. Am I expecting to receive noise like this with amplitudes sometimes over 0.1V? Is this just noise that is inherent in the module? If yes then what is it about the connection with the module to the cDAQ that causes this noise? If no then is there ways of attenuating this noise, through software or hardware. I have tried things like changing the module to different ports, replacing the module itself and the noise is also seen in my simple daqmx LabVIEW VI which just reads the channel signal and plots it.

I am happy to provide more information, just ask away. My aim for the module is to take the signal from a pressure gauge and log the pressure in a program. However the range of output voltages of this gauge is (without amplification) 1.9V to 2.1V for a 0-50 psi pressure range. Is it instead worth trying to increase this output range?

Thanks

[VA.KI]

Hello,

The noise we see here can be normal as this is also based on the environment.

It is possible if you connect the sensor to the input the noise will disappear.

If the noise will stay you can contact NI to check if the device is faulty and need repair.

If this is normal then by averaging the signal you will eliminate the noise, those more, if you are measuring pressure then this should be okay.

Based on the documentation of the NI 9201 about the noise ~0.02V peck to peck should be ok.

Check these links regarding LSB parameters:

https://knowledge.ni.com/KnowledgeArticleDetails?id=kA00Z000000PANfSAO&l=en-US

https://www.ni.com/en-us/support/documentation/supplemental/16/specifications-explained--ni-multifun...

Regarding the rage I think would be better to check this based on sensor documentation or empirically.