Technical data

Cabling
5-13
5
Cabling
After you have completed the rack installation or otherwise
situated the system and associated equipment, proceed as follows
to cable the hardware together.
Note All rack cabling should be contained within the rack
bay. Cabling to external peripheral equipment should
be routed through the rear panel of the rack.
Cables
The system console, printers, and some other peripherals use
EIA-232-D cables. Although EIA-232-D shielded cables can be
successfully used over extended distances, reliable communication
over cables longer than 50 feet depends on the absence of electrical
noise, correct ground potentials at termination points, and other
variables. For this reason, error-free communication cannot be
guaranteed on EIA-232-D cables longer than 50 feet. An alternative
solution to extending cables is to use “short-haul” modems for
devices further than 50 feet from the computer processor.
Two types of cables are commonly found in local area networks:
standard and thin. Some installations may have fiber optic or
twisted pair cables. Standard cabling, the thicker and more
insulated of the two, generally serves as the backbone of the
network. Thinnet cabling usually links individual devices, such as
terminals, to the network, but can be used as the main cabling
device as well.
The standard type of Ethernet cable has the following
characteristics:
❏ A maximum length of 1640 feet (500 m). Shorter segments of
384 feet (117 m), 230 feet (70 m), and 77 feet (23 m) are also
available.