Differential Connections For Grounded Signal Sources - National Instruments PCI-1200 User Manual

Chapter 3 Signal Connections
Grounded
Signal V
s
Source
Common-
Mode
Noise and
V
cm
Ground
Potential
I/O Connector
NI PCI-1200 User Manual

Differential Connections for Grounded Signal Sources

Figure 3-3 shows how to connect a ground-referenced signal source to a
NI PCI-1200 configured for DIFF input mode. Configuration instructions
are in the Analog I/O Configuration
Configuring the NI
1 ACH0
3 ACH2
5 ACH4
+
7 ACH6
–
2 ACH1
4 ACH3
+
6 ACH5
–
8 ACH7
11 AGND
NI PCI-1200 in DIFF Configuration
Figure 3-3. Differential Input Connections for Grounded Signal Sources
With this connection type, the instrumentation amplifier rejects both the
common-mode noise in the signal and the ground-potential difference
between the signal source and the NI PCI-1200 ground (shown as V
Figure 3-3).
section of Chapter 2,
PCI-1200.
PC0
3-10
Installing and
+
+
Measured
–
V
m
Voltage
–
in
cm
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