SCC-2345 crosstalk when using TCs and feedthroughs

[microfanman]

When acquiring two signals from a function generator through a feedthrough (FT01), the lowest channel thermocouple (all TCs go through TC02 modules) get corrupted with crosstalk from the high FT01 channel.

If I short the high FT01 channel, both TCs read correctly. If I use only one TC, that signal is corrupted. The TC and voltage BNC wires are not close together outside the SCC-2345. Inside the SCC-2345, I have placed the wires as far apart as possible.

Systems used: Using Labview 6.1, PCI-MIO-16E-1, SCC-2345, two TC02s, and a FT-01. I have been using Labview's Continuous Input VI to measure the signals. I've tried other VIs as well and the problem persists.

[Filipe A.]

Hello;

The cross talk might be due to a too high Sampling Rate on the system. If the sampling rate is too high, the instrumentation amplifier doesn't have time to settle, and the readings from one channel intefere on the next and so on.

The way to go about this is to increase the interchannel delay in between the channels.

Hope this helps.
Filipe