Nortel Circuit Card 311 Reference page 745

units to configure trunk and signaling type. The remaining three messages
are sent per card to select the make/break ratio and the A-Law and µ-Law
modes.
The signaling and control circuits on the card perform the following functions:
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The signaling and control portion of the E and M Trunk card works with the
system CPU to operate the card hardware. The card receives messages
from the CPU over a signaling channel in the DS-30X loop and returns
status information to the CPU over the same channel. The signaling and
control portion of the card provides analog loop terminations that establish,
supervise, and take down call connections.
Configuration information for the E and M trunk card is downloaded from
the CPU at power-up and by command from maintenance programs.
Configuration messages are sent. One message is sent to configure trunk
and signaling type. The other messages are sent to each card to select the
make/break ratio and the A-Law and Mu-Law modes.
The signaling and control circuits on the card perform the following functions:
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provide interface between the card and the system CPU
— transmit PCM signals from each of the four units to one DS-30X
timeslot in A10 format (ready to send/clear to send—flow control,
handshake format)
— transmit and receive signaling messages over a DS-30X signaling
channel in A10 format
decode received messages to set configuration and activate/deactivate
interface relays for PCM loopback diagnostic purposes
decode outpulsing messages (one per digit) from the CPU to drive
outpulsing relays at 20 pps, 10 pps1 (primary), or 10 pps2 (secondary)
monitor signals from the trunk interface and generate a message when
required for each state change
control disabling and enabling of unit or card
control of A-Law and µ-Law operation modes
control of transmission pad settings
provide an interface between the card and the system CPU
— transmit PCM signals from each of the four units to one DS-30X
timeslot in A10 format (ready to send/clear to send—flow control,
handshake format)
— transmit and receive signaling messages over a DS-30X signaling
channel in A10 format
Nortel Communication Server 1000
Circuit Card Reference
NN43001-311 01.04 Standard
Release 5.0 23 May 2008
Functional description 745