National Instruments AT-MIO-16X - Manual (Page 45)

Chapter 2 Configuration and Installation
© National Instruments Corporation 2-23 AT-MIO-16X User Manual
Differential Connections for Ground-Referenced
Signal Sources
Figure 2-7 shows how to connect a ground-referenced signal source
to an AT-MIO-16X board configured in the DIFF input mode. The
AT-MIO-16X analog input circuitry must be configured for DIFF input
to make these types of connections. Configuration instructions are
included in Chapter 4, Register Map and Descriptions.
Figure 2-7. Differential Input Connections for Ground-Referenced Signals
With this type of connection, the PGIA rejects both the common-mode
noise in the signal and the ground potential difference between the
signal source and the AT-MIO-16X ground, shown as V
cm
in
Figure 2-7.
Ground-
Referenced
Signal
Source
Common-
Mode
Noise,
Ground
Potential,
and so on
Input Multiplexers
AI SENSE
PGIA
V
m
Measured
Voltage
AI GND
-
+
-
+
V
s
V
cm
+
-
-
+
I/O Connector
AT-MIO-16X Board in the DIFF Input Configuration
ACH<0..7>
ACH<8..15>
Gain