National Instruments PCI-6281

© National Instruments | 4-11
M Series User Manual
Connecting Analog Input Signals
Table 4-3 summarizes the recommended input configuration for both types of signal sources.
Table 4-3. Analog Input Configuration
AI
Ground-Reference
Setting
*
Floating Signal Sources
(Not Connected to
Building Ground)
Ground-Referenced
Signal Sources
†
Examples:
• Ungrounded thermocouples
• Signal conditioning with isolated
outputs
• Battery devices
Example:
• Plug-in instruments with
non-isolated outputs
Differential (DIFF)
Non-Referenced
Single-Ended
(NRSE)
Referenced
Single-Ended (RSE)
*
Refer to the Analog Input Ground-Reference Settings section for descriptions of the RSE, NRSE, and
DIFF modes and software considerations.
†
Refer to the
Connecting Ground-Referenced Signal Sources section for more information.
+
–
+
–
AI+
AI–
AI GND
Signal Source DAQ Device
+
–
+
–
AI+
AI–
AI GND
Signal Source DAQ Device
+
–
+
–
AI
AI SENSE
AI GND
Signal Source DAQ Device
+
–
+
–
AI
AI SENSE
AI GND
Signal Source DAQ Device
+
–
+
–
AI
AI GND
Signal Source DAQ Device
Ground-loop potential (V
A
– V
B
) are added
to measured signal.
NOT RECOMMENDED
+
–
+
–
AI
AI GND
V
B
V
A
Signal Source DAQ Device