Rse configuration) -18, Nrse configuration) -18, Figure 4-7 – National Instruments 6023E User Manual
Page 48
Chapter 4
Signal Connections
4-18
ni.com
Single-Ended Connections for Floating Signal
Sources (RSE Configuration)
Figure 4-7 shows how to connect a floating signal source to a channel
configured for RSE mode.
Figure 4-7. 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 device in the NRSE input configuration. Connect
the signal to the positive input of the PGIA, and connect the signal local
ground reference to the negative input of the PGIA. The ground point of the
signal, therefore, connects to the AISENSE pin. Any potential difference
between the device 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
device were referenced to ground, in this situation as in the RSE input
configuration, this difference in ground potentials appears as an error in the
measured voltage.
+
+
+
–
–
–
Measured
Voltage
AIGND
I/O Connector
AISENSE
Selected Channel in RSE Configuration
PGIA
Input Multiplexers
V
s
V
m
Programmable Gain
Instrumentation Amplifier
ACH
Floating
Signal
Source