National Instruments NI 6014 - Manual (Page 42)

Chapter 4 Connecting Signals
NI 6013/6014 User Manual 4-16 ni.com
Figure 4-7 shows how to connect a grounded signal source to a channel
configured for NRSE mode on the NI 6013/6014.
Figure 4-7. Single-Ended Input Connections for Ground-Referenced Signals
Common-Mode Signal Rejection Considerations
Figures 4-4 and 4-7 show connections for signal sources that are
already referenced to some ground point with respect to the NI 6013/6014.
In these cases, the PGIA can reject any voltage caused by ground potential
differences between the signal source and the device. In addition, with
differential input connections, the PGIA can reject common-mode noise
pickup in the leads connecting the signal sources to the device. The PGIA
can reject common-mode signals as long as V
in
+ and V
in
– (input signals)
are both within ±11 V of AIGND.
Selected Channel in NRSE Configuration
Common-
Mode
Noise
and Ground
Potential
Ground-
Referenced
Signal
Source PGIA
Input Multiplexers
–
+
–
+
V
s
V
cm
I/O Connector
AIGND
AISENSE
ACH<0..15>
–
+
Instrumentation
Amplifier
Measured
Voltage
V
m
–
+