Hi community members,
I recently put together a program using LabView 8.0 that runs on my Dell laptop computer.
I am continuously collecting data from four different channels - Ai in., 100Hz, 100s/channel
I am collecting data from:
1) Linear encoder #1
2) Linear encoder #2
3) Load cell output, after signal conditioning - always in tension, so voltage output is always positive
4) Load cell excitation voltage - DC
A) For some reason the voltage that I read with a DMM directly on (4) w.r.t. Ground is off by 2v. All other voltages are not offset. Why?
B) When I run the program on a Sony Vio laptop, signals from (3) are very noisy +/- .2V. Why? All other signals the same, (4) is still offset by 2v.
Thank you for your attention and any valuable input
Solved! Go to Solution.
Sometimes it's simplest to use the Measurement and Automation Explorer (MAX.) to get things working. There you can setup a quick Data-acq. (for NI hardware.) Do you use differential-input mode? Is the load-cell output DC? If yes to both, then it is surprising that the DMM measures differently than the DAQ-device.
Open MAX (Start\Programs\NI\Measure...), find your (NI) hardware, open test-panel...
If the problem isn't solved by using differential-inputs - what NI-DAQ hardware is connected?
Yes! you are right, I did have my measurment mode set to single ended. I changed it to differential and it works like a charm.
Thank you tbd