Lca Shelf Configuration - Nortel DMS-100 Series Maintenance Manual

In the RLCC, the LCM connects two to six DS-1 control-side (C-side) links
to its 20 line sub-groups (LSG). The following LCM components make up
this interface:
2 power converters
2 control complexes (LCM processor and digroup control card)
20 LSGs
The RLCM-EDC has a minimum of two DS-1 links because each primary
link carries one message channel to the LTC+ for the LCM unit and one for
the RMM. Each DS-1 link carries 24 speech channels, making possible 48
to 144 available channels. Four of these channels, are always nailed up for
messaging to the host controller. Other links, up to a total of six, may be
accommodated depending on traffic capacity and the concentration ratio
required.
New LCM processor NT6X51BA has hardware and software capability to
implement the HDLC LAP-D messaging protocol required in the extended
distance capability to the controlling LTC+. The LCM processor cards are a
multi-processor design that partitions the real-time critical work in the
peripheral to allow higher call completion rates than the standard RLCM
product.

LCA shelf configuration

The layout of the LCA shelves and line drawers of the RLCM-EDC are
shown in the following figure "Line concentrating array (LCA) shelf
layout."
An LCA shelf contains the following parts:
one power converter
one control complex
five line drawers
Power converter card
The power converter card (NT6X53), located in slots 01–03 of the LCA,
contains circuits for converting –48V office battery to regulated +5V and
+15V outputs for the shelf circuitry.
Power connections to the two shelves of an LCM are arranged so that one
converter can supply power to both shelves if the mate converter fails.
DMS-100 Family Maintenance Manual ABSK007
Maintenance overview 1-5