Common-Mode Signal Rejection Considerations; Figure 4-8. Single-Ended Input Connections For Ground-Referenced Signals - National Instruments DAQ PCI E Series User Manual

Chapter 4 Signal Connections
Ground-
Referenced
V
Signal s
Source
Common-
Mode
V
cm
Noise
and Ground
Potential
I/O Connector

Common-Mode Signal Rejection Considerations

PCI E Series User Manual
Figure 4-8 shows how to connect a grounded signal source to a channel
on the PCI E Series board configured for NRSE mode.
+
-
Input Multiplexers
+
AIGND
-
Selected Channel in NRSE Configuration

Figure 4-8. Single-Ended Input Connections for Ground-Referenced Signals

Figures 4-5 and 4-8 show connections for signal sources that are
already referenced to some ground point with respect to the
PCI E Series board. In these cases, the PGIA can reject any voltage
caused by ground potential differences between the signal source and
the board. In addition, with differential input connections, the PGIA can
reject common-mode noise pickup in the leads connecting the signal
sources to the board. The PGIA can reject common-mode signals as
long as V + and V -
in
The PCI-MIO-16XE-50 has the additional restriction that (V +
added to the gain times (V +
At gains of 10 and 100, this is roughly equivalent to restricting the two
input voltages to within ±8 V of AIGND.
ACH
+
PGIA
-
AISENSE
(input signals) are both within ±11 V of AIGND.
in
- V -
) must be within ±26 V of AIGND.
in in
4-22
Instrumentation
Amplifier
+
Measured
V
m
Voltage
-
in
© National Instruments Corporation
+ V -
)
in