Chapter 4 Connecting Signals
© National Instruments Corporation 4-9 NI 6115/6120 User Manual
Connections for Ground-Referenced Signal Sources

Figures4-2 and 4-3 show how to connect a ground-referenced signal

source to a channel on the NI6115 and NI 6120, respectively.

Figure 4-2. Pseudodifferential Input Connections on the NI 6115
forGro und-Referenced Signals
Vm
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 kΩ40 pf for ranges > ±10 V
Vs
Vcm
+
+
Common-Mode
Choke