Floating voltage on USB-6210

Hi Every one,

I have an USB-6210, I used Test Panel to read Analog input, i didn't connected any signals at AI, it have a floating voltage.

I have tested on USB-6009, USB-6009 don't have this floating voltage.

When i connected a signal to AI on USB-6210, it read really good.
Is my USB- 6210 damaged?

Connect USB-6009 and 6210 to ComputerFloating voltage on USB-6210USB 6210 read Sine wave 6Vpp- 10 Hz