User manual

Chapter 4 Connecting Signals

Single-Ended Connection Considerations

A single-ended connection is one in which the analog input signal of the

NI 6034E/6035E/6036E device 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.

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 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.

Using your software, you can configure the 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

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 NI 6034E/6035E/6036E 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.

UM.book Page 15 Monday, May 14, 2001 10:32 AM