bad data from daq

[Albert - UC Davis]

I am taking data off of a radar gun. The gun is connected to one channel of a 16 channel circuit board which sends the data through an ide cable to a DAQ notebook card. This exact setup worked at one time on an older computer. Now the signal from the gun is too weak to read. I have watched the data real-time using the test panel in the Measurement & Automation Explorer. In doing so, I noticed one aditional concern. The data peaked whenever I lifted my feet off the ground. This peak was even more dramatic if I had one hand touching the radar gun.

Thanks for the help.
Albert

[Jeremy_C]

Albert,

It sounds like you may have a grounding issue. Is your board configured for reference single-ended (RSE) or non-reference single-ended (NRSE)? When you say "too weak", does this mean you aren't reading anything? What voltage are you expecting to read. Is the laptop plugged in when you are acquiring data? That is, does it have its own ground reference? You may want to analyze your setup as far as determining your various ground references. I would also suggest reading the following tutorial that discusses many factors that need to be taken into account when wiring signals in the field.

Tutorial