Nortel Networks Circuit Card 311 - Manual (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.
Table 211 "Analog message waiting
line card - line interface unit electrical characteristics" (page 548) shows a
summary of the analog line interface unit electrical characteristics.
Table 211
Analog message waiting line card - line interface unit electrical characteristics
Characteristics Description
Impedance 600 ohms
Loop limit
(excluding telephone) 1000 ohms at nominal –48 V
(excluding telephone)
Leakage resistance 30,000 ohms
Ring trip During silent or ringing intervals
Ringing voltage 86 V ac
Signaling Loop start
Supervision Normal battery conditions are continuously applied
(approximately –44.5 V on ring and –2.5 V on tip at
nominal –48 V battery)
Power input from
backplane –48 (can be as low as –42 for DC-powered
systems), +15, +8.5, –150 V and ringing voltage
Insertion loss 4 dB ±1 dB at 1020 Hz
3.5 dB loss for analog to PCM
0.5 dB loss for PCM to analog
Input impedance
The impedance at tip and ring is 600 ohms with a return loss of:
• 20 dB for 200-500 Hz
• 26 dB for 500-3400 Hz
Input impedance
The impedance at tip and ring is 600 ohms with a return loss of:
• 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
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.