Chapter 4
Connecting the Signals
©
National Instruments Corporation
4-17
Single-Ended Connection Considerations
In a single-ended connection, the AI signal is referenced to a ground that
can be shared with other input signals. The input signal connects to the
positive input of the PGIA, and the ground connects to the negative input
of the PGIA.
When every channel is configured for single-ended input, up to 16 AI
channels on the NI 6052E are available. Use single-ended input
connections for any input signal that meets the following conditions:
•
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.
DIFF input connections are recommended for greater signal integrity for
input signals that do not meet the preceding conditions.
Using application software, you can configure the NI 6052E channels
for RSE or NRSE mode. RSE mode is used for floating signal sources.
In this case, the NI 6052E provides the reference ground point for the
external signal. NRSE mode is used for ground-referenced signal sources.
In this case, the external signal supplies its own reference ground point,
and the device should not supply one.
In single-ended configurations, more electrostatic and magnetic noise
couples into the signal connections than in the DIFF configuration.
The coupling is a result of signal path differences. 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 signal conductors.
