Structured Cabling Systems
Cabling standards for LANs such as Ethernet are defined by EIA/TIA
568 and ISO11801 for both copper and fiber cabling plants and is
usually referred to as a Structured Cabling System (SCS). Simply put, the
standards under EIA/TIA and ISO11801 provide a series of requirements
for the physical layout of the cabling plant and performance and testing
criteria, providing a “structure” so that known performance can be
expected when plugging in your network equipment. Properly followed
it is the intent of these standards that the SCS will provide a useful life
of 10 or more years.
Some of the critical yet practical requirements of these standards include
maximum horizontal cable runs of no longer than 90 meters, patch cords
not to exceed 5 meters each and 10 meters combined, specific
construction of horizontal cable such as 4 pairs UTP and STP of no less
than 24 AWG and performance criteria defined as Cat 5e and Cat 6.
Both Cat 5e and Cat 6 are capable of supporting networking speeds up
to 1 Gigabit/second. For industrial applications Cat 5e is recommended
and will meet virtually all needs now and in the future. Patch cords can
be of either solid or stranded construction, with stranded cable providing
improved flexibility. Currently under development are standards for
industrialized versions of copper connectivity offering more robust
interfaces to higher vibration, shock, environmental conditions such as
IEC IP67 ratings.
These standards also apply to fiber cabling, both Single Mode (SM)
and Multi Mode (MM). There are many variations of fiber but the prime
advantages offered by either fiber type include noise immunity, longer
distances and higher bandwidth capabilities. MM cables can extend
from 220 meters up to 550 meters. SM fiber cables can extend up to
40km and beyond! For most industrial applications MM fiber is
recommended as the more cost effective solution while still getting
most of the benefits of fiber.