Black Box Mixed-Media Fiber Hubs
Installation and User Guide (4/99)
the hub on and off when it is placed in or taken out of service, or when it needs to be reset. AC
Power input is auto-ranging, from 100 to 240vac with a frequency of 47 to 63 Hz.
When shipped for use in the U.S. and Canada, a 115vac power cord is included.
AC Power
Bonus Port Slot, configurable via
Port Module (PM)
(SPM - FST shown)
peater Bus (IRB)
rface to unit above.
8
Figure 2.3.c: Black box LH8050A Rear Panel View
Cooling Fan:
The LH8050A is equipped with a low noise 9 cfm fan. The fan will
maintain low temperature operation inside the unit to maximize reliability, even in wiring
closets with ambient temperatures up to 50
°
C.
Bonus Port:
The LH8050A features a bonus port slot that is rear-mounted and is
factory configured with any one of the Switch Port Module (SPM) types. An SPM will segment
the LH8050A from the other parts of the network connected to it, providing flexibility in the
network topology. This flexibility is especially desirable for 100Mbps traffic domains which
are Path Delay Value (PDV) limited.
PMs for the front slots may not be used in the rear Bonus Port slot.
Inter-Repeater Bus (IRB):
The IRB allows an LH8050A unit to be stacked with up
to two LH8050A-special and/or LH8016A-C units to form one logical dual-speed repeater.
Instructions for the using the IRB connectors on the LH8050A are discussed in detail in Section
2.6, "Stacking Black-Box LH8050As".
2.4
Port Modules (PMs)
To provide maximum application flexibility, individual Port Modules (PMs) are
used with the LH8050A. The LH8050A features 16 PM slots on the front of the unit, some
(minimum of 2) or all of which may be configured at a given time. The bonus slot allows for an
optional factory-installed rear-mounted switched Ethernet segment connection, typically to a
backbone. With the bonus slot used, the LH8050A becomes a 16-port dual-speed hub with one
switched up-link.
There are a total of six standard PM cards, each for a specific media cable connector.
A seventh module type is used as a face plate when any front slot is not used. The LH8050A
Connector
1 8
Inter-Re
P3 - Inte
P4 - Interface to unit below.
R
L
ON
OFF
OUT
IN
