© 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
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