National Instruments NI 6014 - Manual (Page 37)

Chapter 4 Connecting Signals
© National Instruments Corporation 4-11 NI 6013/6014 User Manual
Differential Connections for Ground-Referenced
Signal Sources
Figure 4-4 shows how to connect a ground-referenced signal source to
a channel on the device configured in DIFF input mode.
Figure 4-4. Differential Input Connections for Ground-Referenced Signals
With this type of connection, the PGIA rejects both the common-mode
noise in the signal and the ground potential difference between the signal
source and the device ground, shown as V
cm
in Figure 4-4.
Selected Channel in DIFF Configuration
PGIA
–
+
–
+
–
+
–
+
V
cm
V
s
Ground-
Referenced
Signal
Source
Common-
Mode
Noise and
Ground
Potential
I/O Connector
AIGND
AISENSE
Input Multiplexers
V
m
Measured
Voltage
Instrumentation
Amplifier
ACH+
ACH–