Analog Line Interface Units - Avaya Nortel Communication Server 1000 Reference

page 37). The output bus is used by the system controller for output of control data to the line
card. The input bus is used by the system controller for input of line card status data.
A card LAN link bus is common to all of the line/trunk card slots within an IPE module. This
bus is arranged in a master/slave configuration where the controller card is the master and all
other cards are slaves. The module backplane provides each line/trunk card slot with a unique
hardwired slot address. This slot address enables a slave card to respond when addressed
by the controller card. The controller card communicates with only one slave at a time.
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 is 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
of the logic that performs these functions. Each part of the analog line interface unit is discussed
in the following section.
Circuit Card Reference
on page 40 shows a typical example
Line cards
July 2011 39