TOKEN RING FIBER EXTENDERS
18
5.
'
Switch Settings
The switches on the LCL112A-TR are located on the rear panel. These provide the
following functionality.
Switch
Number
Name
Function
1
NODE/
CONC
When ACL is set to ON the NODE/CONC switch defines
whether the LCL112A-TR sources phantom current (i.e.
looks like the NIC in a PC) or provides the valid phantom
load (i.e. looks like the lobe port of a MAU).
To connect to a node (PC or other station/router etc.) set
switch 1 to “NODE” i.e. UP.
To connect to a concentrator (lobe port of a MAU etc.) set
Switch 1 to “CONC” i.e. DOWN.
Note: This switch has no effect when ACL is disabled.
2
LOBE/
TRUNK
When set to “LOBE” the LCL112A-TR uses 802.5J keying
sequences to establish the link. This means that the fiber
link will not insert until the PC on the lobe is inserted on to the
LAN.
When set to “TRUNK” the fiber link is established
immediately. No devices need to be inserted using
phantom before the fiber link comes up.
Lobe mode is selected when the links are established by
switches, stations and routers connected to the LCL112A-
TR in a lobe extension mode to a concentrator port of a
switch or MAU. Lobe mode is the best mode of operation for
inter-switch links and links to the lobe ports of MAUs.
Trunk mode is selected when the fiber link must always be
inserted, e.g. in the Ring In/Ring Out path. Trunk mode has
some limited use in creating a Fiber backbone between two
sites with devices connecting as stations to that backbone.
Trunk mode connections to active MAU lobe ports are not
recommended.
