NI-9227 Isolated Analog Input Module

The NI 9227 has four 2-terminal detachable screw-terminal connectors that provide connections for four simultaneously sampled, isolated analog input channels.

You can connect ground-referenced or floating current sources to the NI 9227. Connect the positive side of the current source to the
AI+ terminal, and connect the negative side of the current source to the AI- terminal. If you make a ground-referenced connection
between the current source and the NI 9227, make sure the voltage on the AI+ and AI- connections are in the channel-to-earth safety
voltage range to ensure proper operation of the NI 9227.

NI-9227

The NI 9227 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 of the NI 9227.

If an application is subject to high vibration, National Instruments recommends that you either use ferrules to terminate wires to the
detachable screw-terminal connector or use the NI 9971 backshell kit to protect the connections. Refer to Figure 6 for an illustration
of using ferrules. Refer to Figure 1 for an illustration of the NI 9971 connector backshell.