9205 all channels reading together

[Cgibsong002]

We have a 9205 in a 9188 xt reading 16 pairs of differential signals, 0-10vdc. This is setup as spares so they're technically not connected to anything but an open connector.

When shooting in a voltage to test my channels, all 16 of my channels in MAX are all reading together. If I put in 8V, they all read 8V. It's differential configuration, nothing tied to COM, and they all show to be correctly wired.

The other guy I'm working with says this is normal and he usually ties up all channels he's not working on with a different voltage so he can test a single channel. I've used this module many times and don't ever recall seeing this kind of thing. Any insights?

[_kb]

You shouldn't expect to see any specific readings on channels left open.  Open channels are free to drift and can be influenced by a wide variety of factors, including signals connected to other channels.

If the results are making it difficult to test a single channel because all lines report similar values, you can do one of several things, including:

• Read only the single channel you are testing.
• Take your colleague's advice and connect any channels that are not of interest to a known voltage, or just short them across Ch+ and Ch- to show 0 V readings.