National Instruments NI 9215 - Manual (Page 15)

© National Instruments Corp. 15 NI 9215 Operating Instructions and Specifications
NI 9215 Circuitry
The NI 9215 channels share a common ground that is isolated from
other modules in the system. The NI 9215 protects each channel
from overvoltages. For more information about overvoltage
protection, refer to the
Specifications section. The incoming analog
signal on each channel is buffered and conditioned by the
instrumentation amplifier and is then sampled by a 16-bit ADC.
The channels have independent track-and-hold amplifiers that
allow you to sample all four channels simultaneously. Refer to
Figures 8 and 9 for input circuitry illustrations of the NI 9215 with
screw terminal and the NI 9215 with BNC.