Nortel Networks 1000 - Manual (Page 455)

Functional description 455
The faceplate of the NT8D09 Analog Message Waiting Line Card is
equipped with a red LED which lights when the card is disabled. At
power-up, the LED flashes as the analog line card runs a self-test. If the
test completes successfully, the card is automatically enabled (if it is
configured in software) and the LED goes out.
Functional description
The NT8D09 Analog Message Waiting Line card contains a
microprocessor that provides the following functions:
• self-identification
• self-test
•
control of card operation
• status report to the controller
• maintenance diagnostics
The NT8D09 Analog Message Waiting Line card also provides:
•
600 ohms balanced terminating impedance
• analog-to-digital and digital-to-analog conversion of transmission and
reception signals for 16 audio phone lines
• transmission and reception of Scan and Signaling Device (SSD)
signaling messages over a DS-30X signaling channel in A10 format
•
on-hook/off-hook status and switchhook flash detection
•
20 Hz ringing signal connection and automatic disconnection when the
station goes off-hook
•
synchronization for connecting and disconnecting the ringing signal
to zero crossing of ringing voltage
• loopback of SSD messages and Pulse Code Modulation (PCM) signals
for diagnostic purposes
• correct initialization of all features at power-up
•
direct reporting of digit dialed (500-type telephones) by collecting dial
pulses
•
connection of –150 V dc at 1 Hz to activate message waiting lamps
• lamp status detection
• disabling and enabling of selected units for maintenance
Nortel Communication Server 1000
Circuit Card Reference
NN43001-311 02.06 Standard
27 August 2008
Copyright © 2003-2008 Nortel Networks
.