National Instruments NI 783xR Benutzerhandbuch

In single-ended input modes, electrostatic and magnetic noise couples into 
the signal connections more than in differential input modes. The coupling 
is the result of differences in the signal path. Magnetic coupling 
is proportional to the area between the two signal conductors. Electrical 
coupling is a function of how much the electric field differs between the 
two conductors.

Figure 2-7 shows how to connect a floating signal source to a channel on 
the NI 783xR configured for RSE input mode.

 

Figure 2-7.  Single-Ended Input Connections for Nonreferenced or Floating Signals

To measure a grounded signal source with a single-ended input mode, you 
must configure the NI 783xR in the NRSE input mode. Then connect the 
signal to the positive input of the NI 783xR instrumentation amplifier and 
connect the signal local ground reference to the negative input of the 
instrumentation amplifier. The ground point of the signal should be 
connected to AISENSE. Any potential difference between the NI 783xR 
ground and the signal ground appears as a common-mode signal at both the 

RSE Input Mode Selected

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Floating

Signal

Source

I/O Connector

AISENSE

AIGND

V

m

Measured

Voltage

Instrumentation

Amplifier

AI+ 

AI–

V

s