National Instruments NI 6225 User Manual

Chapter 4 Analog Input
M Series User Manual 4-16 ni.com
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 Using Non-Referenced Single-Ended (NRSE) Connections for
Floating Signal Sources section for more information about NRSE
connections.
When to Use Referenced Single-Ended (RSE) Connections with Floating
Signal Sources
Only use RSE input connections if the input signal meets the following
conditions.
• The input signal can share a common reference point, AI GND, with
other signals that use RSE.
• 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).
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 Using Referenced Single-Ended (RSE) Connections for
Floating Signal Sources section for more information about RSE
connections.
Using Differential Connections for Floating Signal Sources
It is important to connect the negative lead of a floating source to AI GND
(either directly or through a bias resistor). Otherwise, the source may float

National Instruments NI 6225 Specifications

General

Brand	National Instruments
Model	NI 6225
Category	Media Converter
Language	English