When To Use Non-Referenced Single-Ended (Nrse) Connections With Ground-Referenced Signal Sources; When To Use Referenced Single-Ended (Rse) Connections With Ground-Referenced Signal Sources - National Instruments DAQ X Series User Manual

When to Use Non-Referenced Single-Ended (NRSE)
Connections with Ground-Referenced Signal
Sources
Only use NRSE connections if the input signal meets the following
conditions:
•
•
•
DIFF input connections are recommended for greater signal integrity for
any input signal that does not meet the preceding conditions.
In the single-ended modes, more electrostatic and magnetic noise couples
into the signal connections than in DIFF configurations. 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.
With this type of connection, the NI-PGIA rejects both the common-mode
noise in the signal and the ground potential difference between the signal
source and the device ground.
Refer to the
Ground-Referenced Signal Sources
NRSE connections.
When to Use Referenced Single-Ended (RSE)
Connections with Ground-Referenced Signal
Sources
Do not use RSE connections with ground-referenced signal sources. Use
NRSE or DIFF connections instead.
As shown in the bottom-rightmost cell of Table 4-3, there can be a potential
difference between AI GND and the ground of the sensor. In RSE mode,
this ground loop causes measurement errors.
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The input signal is high-level (greater than 1 V).
The leads connecting the signal to the device are less than 3 m (10 ft).
The input signal can share a common reference point with other
signals.
Using Non-Referenced Single-Ended (NRSE) Connections for
4-21
Chapter 4 Analog Input
section for more information about
X Series User Manual