Table of Contents
Advertisement
Functional
The 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 analog message waiting line card also provides:
•
600-ohm 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 DS30X 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
NT8D09 Analog Message Waiting Line Card
Option 11C and 11C Mini
Page 373 of 544
Technical Reference Guide
Hide quick links:
Advertisement
Chapters
Table of Contents
