National Instruments AT E Series - Manual (Page 68)

Chapter 4 Connecting Signals
© National Instruments Corporation 4-21 AT E Series User Manual
Differential Connections for Ground-Referenced
Signal Sources
Figure 4-6 shows how to connect a ground-referenced signal source to
an AT E Series device channel configured in DIFF input mode.
Figure 4-6. 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 AT E Series device ground, shown as V
cm
in Figure 4-6.
Selected Channel in DIFF Configuration
PGIA
Programmable
Gain
Instrumentation
Amplifier
+
+
–
–
+
–
Input Multiplexers
AISENSE
AIGND
I/O Connector
V
cm
+
–
V
s
ACH+
ACH–
V
m
Common-
Mode
Noise and
Ground
Potential
Ground-
Referenced
Signal
Source
Measured
Voltage