Nortel Networks Circuit Card 311 - Manual (Page 26)

26 Overview
In normal operation, the controller card continually scans (polls) all of the
slave cards connected to the card LAN to monitor their presence and
operational status. The slave card sends replies to the controller on the
input bus along with its card slot address for identification. In its reply, the
slave informs the controller if any change in card status has taken place.
The controller can then prompt the slave for specific information. Slaves
only respond when prompted by the controller; they do not initiate exchange
of control or status data on their own.
When an IPE line card is first plugged into the backplane, it runs a self-test.
When the self-test is completed, a properly functioning card responds to
the next controller card poll with the self-test status. The controller then
queries for card identification and other status information. The controller
then downloads all applicable configuration data to the line card, initializes
it, and puts it into an operational mode.
Analog line interface units
Once the 8-bit digital voice signal has been received by the analog line card,
it must be converted back into an analog signal, filtered, converted from a
4-wire transmission path to a 2-wire transmission path, and driven onto
the analog telephone line.
Figure 4 "Typical analog line interface unit block diagram" (page 27) shows
a typical example of the logic that performs these functions. Each part of
the analog line interface unit is discussed in the following section.
Nortel Communication Server 1000
Circuit Card Reference
NN43001-311 01.04 Standard
Release 5.0 23 May 2008
Copyright © 2003-2008, Nortel Networks
.