ADLINK PCIe-7300A - Manual (Page 27)

Installation 17
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/cPCI/PCIe-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 the cPCI/PCI/PCIe-7300A, it is important to terminate your
cable properly to reduce or eliminate signal reflections in the
cable. The PCI/cPCI/PCIe-7300A support active terminator on
board, you can enable or disable the terminator by software selec-
tion. This is a good way to include termination on the signal trans-
mission.
Additional recommendations apply for all signal connection to your
cPCI/PCI/PCIe-7300A are listed as follows:
1. Separate cPCI/PCI/PCIe-7300A device signal lines from
high-current or high-voltage line. These lines are capa-
ble of inducing currents in or voltages on the cPCI/PCI/
PCIe-7300A if they run in parallel paths at a close dis-
tance. 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.