PCI 6024E signals interfere in DAQ assistant

[Anton Zadorozhnyy]

Hi all,
i have LabVIEW 8.5.
I'm using PCI 6024E card to acquire signals from two separate analog channels, with the same triggering and clocking.
One is data that I'm collecting (1000 samples at 200k Hz sample rate, magnitude: 5 mV), the other one is reference square pulse (4 V).
I use either "Split Signals" or "Select Signals" at the output of DAQ Assistant express VI, and then I plot my signals separately.
When only data cable is connected, everything is fine: i see my data and i don't see the unplugged pulse. When I plug in the pulse - the interfere somehow, and where there was my data I now see something like a convoluted plot of those two.
Any suggestions?
Thank you in advance!
--Anton Zadorozhnyy

[Ima U]

Hello Anton,

What you are describing sounds like you are experiencing Ghosting.  This is a great knowledge base article on how to eliminate ghosting from your measurements.  Please take a look at it and post back if you have any more questions.