User manual

Chapter 2 Analog Input
© National Instruments Corporation 2-21 E Series User Manual
Refer to the Analog Input Terminal Configuration section for descriptions
of the input modes.
Table 2-6. Recommended Input Configurations
Input
Signal Source Type
Floating Signal Sources
(Not Connect To Building
Ground)
Ground-Referenced Signal
Sources
Examples
• Ungrounded thermocouples
• Signal conditioning with
isolated outputs
• Battery devices
Examples
• Plug-in instruments
with non-isolated outputs
Differential (DIFF)
Single-Ended—
Ground Referenced
(RSE)
Single-Ended—
Non-Referenced
(NRSE)
+
–
+
–
V
s
AI –
AI GND
R
ext
AI +
+
–
+
–
V
s
AI +
AI –
AI GND
+
–
+
–
V
s
AI
AI GND
+
–
+
–
V
1
AI
+ V
g
–
AI GND
Ground-loop losses, V
g
, are added
to measured signal.
NOT RECOMMENDED
+
–
+
–
V
s
AI
AI SENSE
AI GND
AI GND
R
ext
+
–
+
–
V
s
AI
AI SENSE
AI GND