Specifications

RADring
Installation & Operation Manual Functional Description
3/11/98 12:33 RI/RO Modules Functional Description 2-27
Automatic cable break protection (TCP) will automatically loop the ring
around (using the back-up path) when the cable is damaged, as in the
short-circuit-on-disconnect function of the IBM data connector. This feature
will function when installed opposite another RADring hub equipped with
the TIO. It can be disabled to achieve plug compatibility with equipment
which does not have a cable break protection facility. The cable break
detection is provided by means of a phantom current on the trunk cable.
The TIO module is switch-selectable for either Ring-In or Ring-Out. Since
the TIO does not regenerate the signal, the segment cable distance between
the TIO Ring-Out module of one hub and the TIO Ring-In module of the
next hub is not defined and varies depending on the configuration of the
ring. In any case the distance should not exceed 80 meters for IBM Type 3
cable at 16 Mbps and 200 meters for Type 1 cable at 16 Mbps.
The TIO can be set to three positions - On, Off or Termination:
On
The TIO module is set to ON whenever the cable break
protection (TCP) facility with automatic loopback is to be
used on the RADring.(The TIO should only be set to the
ON position when working in conjunction with
equipment containing a TCP.) Automatic loopback, in
this state, is only activated if a cable break is detected on
the ring and is activated at both ends of the broken
cable. When a cable break is detected, the FLT indicator
is lit.
Off
The TIO module should be placed in the OFF position
whenever it is not working in conjunction with a remote
TCP.
Termination
The TIO module should be set to TERMINATION ON
whenever the automatic loopback is to be initiated by
the user, and not by a cable break on the ring. A card is
kept in the TERMINATION position to allow a single
RADring to operate as a standalone. In this situation one
generally prefers the card to be in an active state so that
the network can be tested by carrying out the automatic
loop.
Note
The fault indicator will not light up for a TERMINATION setting.
TCR Token-Ring
Copper Repeater
Module
The TCR Token Ring Copper Repeater module is used to extend the
distance over a shielded or unshielded twisted pair trunk operating
between RADring modular hubs. Normally operating in pairs, the TCRs
ensure that there is always signal regeneration on the ring, irrespective of
which stations are active on the ring. The TCR meets all the applicable IEEE
02.5 and IBM Token Ring requirements, and supports both 16 and 4 Mbps
networks.