Line Concentrating Module - Nortel DMS-100 Series Maintenance Manual

Line concentrating module

The LCM is the basic design building block of the remote peripheral group.
The control side (C-side) of an LCM interfaces with the host network over
DS30A links. The RLCM-EDC connects over two to six DS-1 links to the
host network. Links connect through a controller peripheral like a line trunk
controller PLUS (LTC+).
When the LCM connects to DS-1 links, the LCM can function as an
RLCM-EDC. The DS30A ports of the LCM map to DS-1 interface cards.
The cards connect to the host office. These DS30A ports are on the digroup
control cards (DCC) of the LCM.
The LCM contains two shelves called line concentrating arrays (LCA).
Each LCA contains five line drawers. A fully equipped LCM contains ten
line drawers. A fully-equipped LCM supports 640 subscriber lines. Each
LCA has a control complex, processor, digroup control card and power
converter. The control units operate in a load sharing mode. If one of the
processors fails, the mate processor takes complete control of the LCM. If
one power converter fails, the power converter that remains can supply
power to all line cards of the LCM.
The RLCM-EDC contains a dual-unit LCM (NTNX28AA), mounted in an
LCM shelf assembly. The NTNX28AA contains the following components:
an NT6X51BA processor card with three Motorola 68302 processors in
a tight coupled distributed process architecture.
a main processor (MP) with four Megabytes (MB) of read-only memory
(ROM) on two banks, (active/standby)
a C-side processor (CP) that terminates C-side messaging data in high
data link controller (HDLC) or DMS-X format
a P-side processor (PP) that operates the serial communication links
between the NT6X51BA card and the bus interface card (BIC). The
NT6X51BA card and the BIC are in each line drawer of the LCM.
The LCM contains the following cards:
NT6X53AA—Power converter 5V/15V
NT6X51BA—LCM processor with 4MB memory (two banks)
NT6X52AA—Digroup controller
NT6X54AA—Bus interface card (BIC) (up to ten)
NT6X21AD—Meridian electronic business set (EBS)
DMS-100 Family Maintenance Manual ABSK007
RLCM-EDC hardware 3-3