Signal
Description
AI+
Positive analog input signal connection
AI-
Negative analog input signal connection
Table 1. Signal Descriptions
Connecting Signal Sources
You can connect ground-referenced or floating signal sources to the NI-9230.
If you make a ground-referenced connection between the signal source and the
NI-9230, make sure the voltage on the AI+ and the AI- connections are in the
channel-to-earth safety voltage range to ensure proper operation of the NI-9230.
Refer to the device datasheet on
for more information about
operating voltages and overvoltage protection.
Figure 3. Connecting a Grounded Signal Source
NI 9230
AI+
AI–
+
–
Signal
Source
Common
Mode
Voltage
Figure 4. Connecting a Floating Signal Source
NI 9230
AI+
AI–
+
–
Signal
Source
Integrated Electronic Piezoelectric (IEPE) Sensors
The NI-9230 provides an IEPE excitation current for each channel to measure the
IEPE sensors. Typical IEPE sensors have a case that is electrically isolated from the
IEPE electronics. As a result, connecting the sensor to the NI-9230 results in a
floating connection even though the case of the sensor is grounded.
Wiring for High-Vibration Applications
If your application is subject to high vibration, NI recommends that you follow these
guidelines to protect connections to the NI-9230 with screw terminal:
© National Instruments
9
NI-9230 Getting Started
