Nortel Networks Circuit Card 311 - Manual (Page 136)

136 NT1R20 Off-Premise Station Analog Line card
Signaling and control – This portion of the card provides circuits that
establish, supervise, and take down call connections. These circuits work
with the system CPU to operate line interface circuits during calls. The
circuits receive outgoing call signaling messages from the CPU and return
incoming call status information over the DS-30X network loop.
Circuit power
The +8.5 V dc input is regulated down to +5 V dc for use by the digital logic
circuits. All other power to the card is used by the line interface circuits.
The ±15.0 V dc inputs to the card are used to power the analog circuits. The
+5 V dc from the module power supply is used for the analog hybrid. The
–48.0 V dc input is for the telephone battery. Ringing power for telephones
is 86 Vrms ac at 20 Hz on –48 V dc. The Rsync signal is used to switch
the 20 Hz ringing on and off at the zero cross-over point to lengthen the
life of the switching circuits.
This section lists the electrical characteristics of the OPS analog line card.
Analog line interface
Table 64 "OPS analog line card - electrical characteristics" (page 136) lists
the electrical characteristics of NT1R20 OPS analog line card line interface
units.
Table 64
OPS analog line card - electrical characteristics
Characteristic Specification
Terminal impedance (TIMP) 600 or 900 ohms
Balance impedance (BIMP) 600 or 900 ohms, 3COM, or 3CM2
DC signaling loop length (max) 2300 ohm loop (including resistance of
telephone) with nominal battery of –48 V dc
Battery supply voltage –42 to –52.5 V dc
Minimum detected loop current 16 mA
Ground potential difference ± 3 V
Line leakage
≥
30k ohms, tip-to-ring, tip-to-ground,
ring-to-ground
AC induction rejection 10 V rms, tip-to-ring, tip-to-ground,
ring-to-ground
Table 64 "OPS analog line card - electrical characteristics" (page 136) lists
the electrical characteristics of OPS analog line card line interface units.
Nortel Communication Server 1000
Circuit Card Reference
NN43001-311 01.04 Standard
Release 5.0 23 May 2008
Copyright © 2003-2008, Nortel Networks
.