Figure 3-3 – National Instruments PCI-1200 User Manual
Page 32
Chapter 3
Signal Connections
3-10
© National Instruments Corporation
Differential Connections for Grounded Signal Sources
Figure 3-3 shows how to connect a ground-referenced signal source to a
PCI-1200 board configured for DIFF input. Configuration instructions are
in the
section in Chapter 2,
Figure 3-3. Differential Input Connections for Grounded Signal Sources
With this type of connection, the instrumentation amplifier rejects both the
common-mode noise in the signal and the ground-potential difference
between the signal source and the PCI-1200 ground (shown as V
cm
in
Figure 3-3).
+
+
Grounded
Signal
Source
V
m
Measured
Voltage
V
s
+
I/O Connector
PCI-1200 in DIFF Configuration
1
3
5
7
2
4
6
8
Common-
Mode
Noise,
Ground
Potential
ACH0
AGND
11
ACH2
ACH4
ACH6
ACH1
ACH3
ACH5
ACH7
V
cm
–
+
PC0
–
–
–