Using Differential Connections For Ground-Referenced Signal Sources - National Instruments DAQ X Series User Manual

Chapter 4 Analog Input
Using Differential Connections for
Ground-Referenced Signal Sources
Figure 4-10 shows how to connect a ground-referenced signal source to the
MIO X Series device configured in differential mode.
With this type of connection, the NI-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
AI+ and AI– must both remain within ±11 V of AI GND.
X Series User Manual
Artisan Technology Group - Quality Instrumentation ... Guaranteed | (888) 88-SOURCE | www.artisantg.com
Ground-
+
Referenced
V
Signal
s
–
Source
Common-
+
Mode
V
cm
Noise and
–
Ground
Potential
Input Multiplexers
AI SENSE
AI GND
I/O Connector
MIO X Series Device Configured in Differential Mode
Figure 4-10. Differential Connections for Ground-Referenced Signal Sources
4-22
AI +
Instrumentation
Amplifier
+
PGIA
AI –
–
V
m
in the figure.
cm
+
Measured
Voltage
–
ni.com