National Instruments NI 9229E - Manual (Page 7)

© National Instruments Corp. 7 NI 9229E/9239E
The NI 9229E/9239E analog input channels are floating with
respect to earth ground and each other. The incoming analog signal
on each channel is conditioned, buffered, and then sampled by a
24-bit Delta-Sigma ADC.
Each channel provides an independent signal path and ADC,
enabling you to sample all four channels simultaneously. Refer
to Figure 5 for an illustration of the circuitry for one channel.
Figure 5. Input Circuitry for One Channel of the NI 9229E/9239E
NI 9229E/9239E
AI+
AI–
ADC
Amplifier
Overvoltage
Protection
Prefilter