Unfortunately I will need a little more information in order to provide you with a useful answer. Please include some of the following information so that we can better understand your system and situation:
- What NI DAQ device are you using for acquisition?
- What other hardware are you using?
- Does the signal float all the time or does it ever read correctly? Try to describe what you are seeing in a little more detail.
- Are you acquiring any other signals?
- What software are you using? Do you see this in LV? MAX? CVI?
- Have you tried any other input mode configuration, such as RSE or NRSE?
You should be running these tests through the test panels in Measurement & Automation Explorer (MAX) to ensure that the problem is not in software. If so, see if
moving it to a different channel corrects the problem.
Please review the following documentation to make sure that you are using the correct input mode and there are no ground loops causing errors:
http://zone.ni.com/devzone/conceptd.nsf/2d17d611efb58b22862567a9006ffe76/01f147e156a1be15862568650057df15?OpenDocument
Also, there is a lot of useful information on ni.com/support that can provide a lot of useful information for commonly seen problems.
Regards,
Michael Haag
Applications Engineer
National Instruments
