Nortel Networks 1000 - Manual (Page 664)

664 NT8D15 E and M Trunk card
— 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 A-Law and Mu-Law operation modes
• control transmission pad settings
The signaling and control portion of the trunk card works with the CPU to
operate the card hardware. The card receives messages from the CPU
over a signaling channel in the DS30X loop and returns status information
to the CPU over the same channel. The signaling and control portion of
the card provides the means for analog loop terminations to establish,
supervise and take down call connections.
The signaling and control operation of the card performs many functions
which are handled by different functional units. Some of the functions of
the signaling and control portion of the E & M card are:
•
Communications between the card and the CPU
• Monitor signals from the trunk interface and generate a message when
required for each state change
• Decode received messages and activate/deactivate configuration and
interface relays PCM loopback for diagnostic purposes
•
Disable and enable units for maintenance
•
Drive Light Emitting Diode (LED) on faceplate
• Decode outpulsing messages (one per digit) from the CPU to drive
outpulsing relays
— Make break ratios (20pps, 10pp1, 10pps2) are downloaded by
software.
• Control of A/mu-law operation
Nortel Communication Server 1000
Circuit Card Reference
NN43001-311 02.06 Standard
27 August 2008
Copyright © 2003-2008 Nortel Networks
.