Nortel Circuit Card 311 Reference page 548

548 NT8D09 Analog Message Waiting Line card
Power for lighting the message waiting lights is provided by either the
peripheral equipment power supply or the ringing generator. Logic on the
message waiting line card interrupts the –150 V dc signal at 1 Hz intervals
to provide a flashing message waiting light.
Technical summary or
Electrical specifications
Analog line interface
The NT8D09 Analog Message Waiting Line Card meets the EIA/TA464
standard for ONS Type II line cards.
line card - line interface unit electrical characteristics" (page 548)
summary of the analog line interface unit electrical characteristics.
Table 211
Analog message waiting line card - line interface unit electrical characteristics
Characteristics
Impedance
Loop limit
(excluding telephone)
Leakage resistance
Ring trip
Ringing voltage
Signaling
Supervision
Power input from
backplane
Insertion loss
Input impedance
The impedance at tip and ring is 600 ohms with a return loss of:
•
•
Input impedance
The impedance at tip and ring is 600 ohms with a return loss of:
•
•
Copyright © 2003-2008, Nortel Networks
.
20 dB for 200-500 Hz
26 dB for 500-3400 Hz
20 dB for 200-500 Hz
26 dB for 500-3400 Hz
Nortel Communication Server 1000
Circuit Card Reference
NN43001-311 01.04 Standard
Release 5.0 23 May 2008
Table 211 "Analog message waiting
Description
600 ohms
1000 ohms at nominal –48 V
(excluding telephone)
30,000 ohms
During silent or ringing intervals
86 V ac
Loop start
Normal battery conditions are continuously applied
(approximately –44.5 V on ring and –2.5 V on tip at
nominal –48 V battery)
–48 (can be as low as –42 for DC-powered
systems), +15, +8.5, –150 V and ringing voltage
4 dB ±1 dB at 1020 Hz
3.5 dB loss for analog to PCM
0.5 dB loss for PCM to analog
shows a