Connections For Nonreferenced Or Floating Signal Sources - National Instruments NI 6115/6120 User Manual

Connections for Nonreferenced or Floating Signal Sources

+
Floating
V
Signal
s
Source
–
Bias
Current
Return
Paths
Bias
Resistor
(see text)
I/O Connector
© National Instruments Corporation
Figures 4-4 and 4-5 show how to connect a floating signal source to a
channel on the NI 6115 and NI 6120, respectively.
Common-Mode
Choke
ACH0+
ACH0–
ACH0GND
ACH0 Connections Shown
Figure 4-4. Differential Input Connections on the NI 6115
AC Coupling
*
*
100 pf
1 M
10 nf
*
for Nonreferenced Signals
4-11
Chapter 4 Connecting Signals
Instrumentation
Amplifier
+
PGIA
+
Measured
–
V
m
Voltage
–
10 kΩ40 pf for ranges > ±10 V
NI 6115/6120 User Manual