Acquired Data in MATLAB from using USB 6210 different channels

[hwasif]

I am using NI USB 6210 to measure the vibration data comming from accelerometer in the range of +-0.5V. i am acquiring data in MATLAB data acquisation tool box. The problem I am facing is that I am using Single Ended mode and selecting 3 analogue channel to acquire data. But they have DC offset voltage with 1 or 2 data line but when I select only 1 channel it has no offset voltage and output oscillate around zero. All the accelerometers are grouded and atttached to AIGND point

addchannell(ai, [1 2 3])

Any one have the idea to solve this issue

[S.Limb]

Hi hwasif

I will be looking into your problem for you and giving you some suggestions to progress with your application, as I understand it so far you have 3 input channels that are reading unexpected values due to offset voltages.

By how much is the offset voltage altering? If you test each channel separately and the channels together what kind of readings do you get?

In the measurement and Automation explorer, MAX, have you tried self testing/ self calibrating the device, as it may just be an internal alteration that can easily be fixed by calibrating the device.

Not using differential input voltages can also cause offset issues, so this could be something to look into to avoid the issue in the future, I have linked a few articles on this.

I also found an example online which you may be able to implement to overcome the issue you are noticing.

Let me know how you get on with these links and please ask any further questions regarding your device. If you have any additional information please also include this, the more information I have, the better.

Thank you