National Instruments AT E Series - Manual (Page 71)

Chapter 4 Connecting Signals
AT E Series User Manual 4-24 ni.com
Single-Ended Connection Considerations
A single-ended connection is one in which the AT E Series device AI
signal is referenced to a ground that can be shared with other input signals.
The input signal is tied to the positive input of the PGIA, and the ground is
tied to the negative input of the PGIA.
When every channel is configured for single-ended input, up to 16 analog
input channels are available (up to 64 channels on the AT-MIO-64E-3).
You can 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 AT E Series device are less than
10 ft (3 m).
• The input signal can share a common reference point with other
signals.
DIFF input connections are recommended for greater signal integrity for
any input signal that does not meet the preceding conditions.
You can software configure the AT E Series device channels for two
different types of single-ended connections—RSE configuration and
NRSE configuration. The RSE configuration is used for floating signal
sources; in this case, the AT E Series device provides the reference ground
point for the external signal. The NRSE input configuration is used for
ground-referenced signal sources; in this case, the external signal supplies
its own reference ground point and the AT E Series device should not
supply one.
In single-ended configurations, more electrostatic and magnetic noise
couples into the signal connections than in differential 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.