Nortel Networks 1000 - Manual (Page 263)

Functional description 263
— programming of loop interface control circuits for administration of
channel operation
— maintenance diagnostics
•
interface with the line card circuit
— converts on/off-hook, and ringer control messages from the DS-30X
loop into A/B bit manipulations for each time slot in the E1 data
stream, using channel associated signaling.
• the front panel LED when the card is enabled or disabled by
instructions from the NT8D01 controller card.
Card LAN interface
Maintenance data is exchanged with the Common Equipment CPU over a
dedicated asynchronous serial network called the Card LAN link. The Card
LAN link is described in
“Card LAN link” (page 25) .
Sanity Timer
The LEI also contains a sanity timer that resets the microcontroller in the
event of a loss of program control. If the timer is not properly serviced
by the microcontroller, it times out and causes the microcontroller to be
hardware-reset. If the microcontroller loses control and fails to service the
sanity timer at least once per second, the sanity timer automatically resets
the microcontroller restoring program control.
Man-Machine Interface
The LEI provides an optional Man-Machine Interface (MMI) that is primarily
used for E1 link performance monitoring and problem diagnosis. The
MMI provides alarm notification, E1 link performance reporting, and fault
isolation testing. The interface is accessed through connections from the
I/O panel to a terminal or modem. Multiple cards (up to 64) can be served
through one MMI terminal or modem by linking the LEIs through a daisy
chain.
The MMI is an optional feature, since all E1 configuration settings are
performed through dip switch settings or preconfigured factory default
settings. Available MMI commands, and their functionality, are discussed
in-depth in
“Man-Machine E1 maintenance interface software” (page 284) .
Nortel Communication Server 1000
Circuit Card Reference
NN43001-311 02.06 Standard
27 August 2008
Copyright © 2003-2008 Nortel Networks
.