Chapter 4
Signal Connections
PCI-MIO E Series User Manual
4-20
©
National Instruments Corporation
Single-Ended Connections for Floating Signal
Sources (RSE Configuration)
Figure 4-6 shows how to connect a floating signal source to a channel
on the PCI-MIO E Series board configured for RSE mode.
Figure 4-6. Single-Ended Input Connections for Nonreferenced or Floating Signals
Single-Ended Connections for Grounded Signal
Sources (NRSE Configuration)
To measure a grounded signal source with a single-ended configuration,
you must configure your PCI-MIO E Series board in the NRSE input
configuration. The signal is then connected to the positive input of the
PCI-MIO E Series PGIA, and the signal local ground reference is
connected to the negative input of the PGIA. The ground point of the
signal should, therefore, be connected to the AISENSE pin. Any
potential difference between the PCI-MIO E Series ground and the
signal ground appears as a common-mode signal at both the positive and
negative inputs of the PGIA, and this difference is rejected by the
amplifier. If the input circuitry of a PCI-MIO E Series board were
referenced to ground, in this situation as in the RSE input configuration,
this difference in ground potentials would appear as an error in the
measured voltage.
V
s
+
+
+
-
-
-
V
m
Measured
Voltage
Floating
Signal
Source
ACH<0..15>
AIGND
Instrumentation
Amplifier
I/O Connector
AISENSE
Selected Channel in RSE Configuration
PGIA
Input Multiplexers