National Instruments NI 6120 - Manual (Page 47)

Chapter 4 Connecting Signals
© National Instruments Corporation 4-9 NI 6115/6120 User Manual
Connections for Ground-Referenced Signal Sources
Figures 4-2 and 4-3 show how to connect a ground-referenced signal
source to a channel on the NI 6115 and NI 6120, respectively.
Figure 4-2. Pseudodifferential Input Connections on the NI 6115
for Ground-Referenced Signals
V
m
ACH0 Connections Shown
PGIA
100 pf
*
10 nf
Ground-
Referenced
Signal
Source
Common-
Mode
Noise and
Ground
Potential
AC Coupling
1 M
*
Instrumentation
Amplifier
I/O Connector
ACH0GND
ACH0–
ACH0+
Measured
Voltage
+
–
+
–
*
10 k Ω 40 pf for ranges > ±10 V
V
s
V
cm
+
–
+
–
Common-Mode
Choke