National Instruments NI 783xR Benutzerhandbuch

© National Instruments Corporation

positive and negative inputs of the instrumentation amplifier. The 
instrumentation amplifier rejects this difference. If the input circuitry of a 
NI 783xR is referenced to ground in RSE input mode, this difference in 
ground potentials appears as an error in the measured voltage.

Figure 2-8 shows how to connect a grounded signal source to a channel on 
the NI 783xR configured for NRSE input mode.

Figure 2-8.  Single-Ended Input Connections for Ground-Referenced Signals

Figure 2-5 and Figure 2-8 show connections for signal sources that are 
already referenced to some ground point with respect to the NI 783xR. 
In these cases, the instrumentation amplifier can reject any voltage caused 
by ground potential differences between the signal source and the device. 
With differential input connections, the instrumentation amplifier can 
reject common-mode noise pickup in the leads connecting the signal 
sources to the device. The instrumentation amplifier can reject 
common-mode signals when V+

in

 and V–

in

 (input signals) are both within 

their specified input ranges. Refer to Appendix A, 

, for more 

information about input ranges.

NRSE Input Mode Selected

–

+

–

+

–

+

–

+

V

cm

V

s

Ground-

Referenced

Signal

Source

Common-

Mode

Noise and

Ground

Potential

I/O Connector

AISENSE

AIGND

V

m

Measured

Voltage

Instrumentation

Amplifier

AI+ 

AI–