Nortel Networks 1000 - Manual (Page 459)

Functional description 459
•
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
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 the
following:
• 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
Nortel Communication Server 1000
Circuit Card Reference
NN43001-311 02.06 Standard
27 August 2008
Copyright © 2003-2008 Nortel Networks
.