Справочник Пользователя для National Instruments NI 9236

The NI 9235/9236 is isolated from earth ground. However, the 
individual channels are not isolated from each other. The EXC 
terminals all connect internally to a common excitation supply. 
You must connect each EXC terminal to only one gage to maintain 
the channel-to-channel crosstalk performance of the module.

Each channel on the NI 9235/9236 has an independent 24-bit ADC 
and input amplifier that enables you to sample signals from all 
eight channels simultaneously. Refer to Figures 5 and 6 for 
illustrations of the input circuitry for one channel of the 
NI 9235/9236.