Chapter 2
Hardware Overview of the NI 78xxR
©
National Instruments Corporation
2-9
R Series Intelligent DAQ User Manual
Figure 2-5 summarizes the recommended input mode for both types of
signal sources.
Figure 2-5.
Summary of Analog Input Connections
+
–
+
–
V
1
AI<
i
>
AISENSE
AIGND<
i
>
+
–
+
–
V
1
AI<
i
>
AISENSE
AIGND<
i
>
See text for information on bias resistors.
+
–
+
–
V
1
AI<
i
>
AIGND<
i
>
+
–
+
–
V
1
AI
+ V
g
–
AIGND
Ground-loop losses, V
g
, are added to
measured signal.
NOT RECOMMENDED
+
–
+
–
V
1
AI<
i
>(+)
AI<
i
>(–)
AIGND<
i
>
+
–
+
–
V
1
AI<
i
>(+)
AI<
i
>(–)
AIGND<
i
>
See text for information on bias resistors.
Signal Source Type
Floating Signal Source
(Not Connected to Building Ground)
Grounded Signal Source
Examples
• Ungrounded Thermocouples
• Signal Conditioning with
Isolated
Outputs
• Battery Devices
Examples
• Plug-in Instruments with
Nonisolated
Outputs
Input
Differential
(DIFF)
Single-Ended—
Ground
Referenced
(RSE)
Single-Ended—
Nonreferenced
(NRSE)
Summary of Contents for NI 781 R Series
Page 1: ...PXI 7842...
