Chapter 2 Preparing for Installation
Installation Site Requirements
2-18
Cisco 12404 Internet Router Installation and Configuration Guide
OL-11636-01
Site Wiring
This section offers site wiring guidelines for setting up the plant wiring and
cabling at your site. When planning the location of the new system, consider the
following:
•
Electromagnetic interference (EMI)
•
Distance limitations for signaling and unshielded conductors
Electromagnetic Interference
Electromagnetic interference can occur between the signal on the wires and
external or ambient EMI fields when the wires are run for any significant distance.
This fact has two implications for the construction of plant wiring.
•
Bad wiring practice can result in radio interference emanating from the plant
wiring.
Warning
Strong EMI, especially when it is caused by lightning or radio transmitters, can
destroy the signal drivers and receivers in the Cisco 12404 router, and can
create an electrical hazard by conducting power surges through lines and may
cause damage to the equipment.
Note
To predict and remedy strong EMI, you may need to consult experts in
radio frequency interference (RFI).
If you use twisted-pair cable in your plant wiring with a good distribution of
grounding conductors, the plant wiring is unlikely to emit radio interference. If
you exceed the recommended distances, use a high-quality twisted-pair cable with
one ground conductor for each data signal when applicable.
todd.book Page 18 Tuesday, November 27, 2007 6:02 PM