7 wiring and termination, Wiring and termination – ADLINK PCI-7300A User Manual

Page 27

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Installation

15

2.7 Wiring and Termination

Transmission line effects and environment noise, particularly on
clock and control lines, can lead to incorrect data transfers if you
do not take care when running signal wires to and from the
devices.

Take the following precautions to ensure a uniform transformation
line and minimize noise pickup:

1. Use twisted-pair wires to connect digital I/O signals to

the device. Twist each digital I/O signal with a GND line.
In PCI-7300A, 50 signals are used as GND.

2. Place a shield around the wires connecting digital I/O

signal to device.

3. Route signals to the devices carefully. Keep cabling

away from noise sources, such as video monitor.

For cPCI/PCI-7300A, it is important to terminate your cable prop-
erly to reduce or eliminate signal reflections in the cable. The PCI-
7300A support active terminator on board, you can enable or dis-
able the terminator by software selection. This is a good way to
include termination on the signal transmission.

Additional recommendations apply for all signal connection to your
cPCI/PCI-7300A are listed as follows:

1. Separate cPCI/PCI-7300A device signal lines from high-

current or high-voltage line. These lines are capable of
inducing currents in or voltages on the cPCI/PCI-7300A
if they run in parallel paths at a close distance. To reduce
the magnetic coupling between lines, separate them by
a reasonable distance if they run in parallel, or run the
lines at right angles to each other.

2. Do not run signal lines through conducts that also con-

tain power lines.

3. Protect signal lines from magnetic fields.

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