Equinox Systems MEGAPORT, Справочник по аппаратуре

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46 Equinox MEGAPORT Hardware Reference Manual
LD Cabling Schemes
There are two recommended cabling schemes for connecting devices
to MEGAPORT LD ports. Both methods are illustrated in Figure 4-5.
The first scheme uses 25 pair telco extension cables for the long
distance portion of the cable run and then uses the Equinox 210117
LD modular splitter to connect a group of ports in close proximity to
each other to the MEGAPORT.
The second scheme uses a telephone punch block to interface the
MEGAPORT with the individual two-twisted-pair cables that are run
to modular wall outlets.
Both schemes have their advantages and disadvantages. The Equi-
nox pinouts match standard telephone cabling practices. Thus, when
planning an installation in a new building, a telephone installer can
connect wall outlets to punch block and the MEGAPORT round cable
telco connector can be connected to the punch block directly, with no
special consideration on the part of the installer to its use for data
instead of voice. Alternatively, the modular splitter is useful when a
number of devices located some distance (i.e. in another building) are
required to be connected to the MEGAPORT.
CAUTION
Cabling Between Buildings
When connecting devices to LD ports located in another
building, the potential for lightning induced surges is
highly likely, especially if the wiring is unprotected.
This is usually caused by a shift in the ground potential
between the two buildings. The LD ports are protected
due to their on-board surge suppression. However, the
surge can be transmitted to the device connected to the
LD port, with a high probability of damage occurring.
To protect terminals and other devices connected to LD
ports, Equinox strongly recommends the use of the
Equinox LDA-232 on the terminal side. The surge
suppression on the LDA-232 should protect the terminal
equipment in this case, although in severe cases the
LDA-232 may be sacrificed in place of the terminal
equipment.