National Instruments Data Acquisition Device NI USB-621x - Taking Non-Referenced Single-Ended (NRSE) Measurements

Chapter 4 Analog Input
NI USB-621x User Manual 4-38 ni.com
Taking Non-Referenced Single-Ended (NRSE) Measurements
To reach a compromise between RSE and differential measurements, you
can use an NRSE measurement configuration. This configuration allows
for a remote sense for the negative (–) input of the instrumentation
amplifier (PGIA) that is shared among all channels configured for NRSE
mode. The behavior of this configuration is similar to that of RSE
connections, except it provides improved noise rejection. Figure 4-26
shows an NRSE connection configuration.
Figure 4-26. Connecting to the USB-6215/6216/6218 in NRSE Mode
In NRSE connection configuration, each input channel is measured with
respect to AI SENSE.
AI 1
AI 0
AI GND
Mux
ADC
PGIA
AI SENSE
USB-6215/6216/6218