User manual

Chapter 4 Connecting Signals
NI 6034E/6035E/6036E User Manual 4-12 ni.com
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
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
UM.book Page 12 Monday, May 14, 2001 10:32 AM