Nortel Networks Circuit Card 311 Manuel d'utilisateur Page 28

  • Télécharger
  • Ajouter à mon manuel
  • Imprimer
  • Page
    / 113
  • Table des matières
  • MARQUE LIVRES
  • Noté. / 5. Basé sur avis des utilisateurs
Vue de la page 27
28 Overview
amplifies the result. On some of the line cards, the gain of these filters can
be programmed by the system controller. This allows the system to make
up for line losses according to the loss plan.
Balancing network
Depending on the card type, the balancing network provides a 600
3
/4, 900
3
/4, 3COM or 3CM2 impedance matching network. It also converts the 2-wire
transmission path (tip and ring) to a 4-wire transmission path (Rx/ground
and Tx/ground). The balancing network is usually a transformer/analog
(hybrid) circuit combination, but can also be a monolithic Subscriber Line
Interface Circuit (SLIC) on the newer line cards.
Line interface and foreign voltage protection
The line interface unit connects the balancing network to the telephone
tip and ring pairs. The off-premise line card (NT1R20) has circuitry that
protects the line card from foreign voltage surges caused by accidental
power line connections and lightning surges. This protection is necessary if
the telephone line leaves the building where the switch is installed.
The line interface unit has a relay that applies the ringing voltage onto the
phone line. See Figure 4 "Typical analog line interface unit block diagram"
(page 27). The RSYNC signal from the 20 Hz (nominal) ringing voltage
power supply is used to prevent switching of the relay during the current
peak. This eliminates switching glitches and extends the life of the switching
relay.
The off-hook detection circuit monitors the current draw on the phone line.
When the current draw exceeds a preset value, the circuit generates an
off-hook signal that is transmitted back to the system controller.
The message waiting circuit on message waiting line cards monitors the
status of the message waiting signal and applies –150 V dc power to the
tip lead when activated. This voltage is used to light the message waiting
lamps on phones that are equipped with that feature. The high voltage
supply is automatically disconnected when the phone goes off-hook. Newer
line cards can sense when the message waiting lamp is not working and
can report that information back to the system controller.
Digital line interface units
The NT8D02 Digital Line card provides voice and data communication
links between a switch and modular digital telephones. These lines
carry multiplexed PCM voice, data and signaling information as Time
Compression Multiplexed (TCM) loops. Each TCM loop can be connected
to a Nortel "Meridian Modular Digital" telephone.
Nortel Communication Server 1000
Circuit Card Reference
NN43001-311 01.04 Standard
Release 5.0 23 May 2008
Copyright © 2003-2008, Nortel Networks
.
Vue de la page 27
1 2 ... 23 24 25 26 27 28 29 30 31 32 33 ... 112 113

Commentaires sur ces manuels

Pas de commentaire

LG AS876 Handbücher

Bedienungsanleitungen und Benutzerhandbücher für Nein LG AS876.
Wir stellen 2 PDF-Handbücher LG AS876 zum kostenlosen herunterladen nach Dokumenttypen zur Verfügung Schnellstart Anleitung


Lg AS876 Schnellstart Anleitung (2 Seiten)


Marke: Lg | Kategorie: No info | Größe: 1.85 MB |

 

Inhaltsverzeichnis





Weitere Produkte und Handbücher für Nein LG

Modelle Dokumententyp
WT1701CW Energienachweis   LG WT1701CW Energy Guide, 1 Seiten
LFX28979SB Energienachweis   LG LFX28979SB Energy Guide, 1 Seiten
VS985 Schnellstart Anleitung   LG VS985 Quick Start Guide (Spanish), 2 Seiten
LFC21770ST Energienachweis   LG LFC21770ST Energy Guide, 1 Seiten
47LW6500 Energienachweis   LG 47LW6500 Energy Guide, 1 Seiten
65UB9200 Energienachweis   LG 65UB9200 Energy Guide, 1 Seiten
D321 Schnellstart Anleitung   LG D321 Quick Start Guide (Spanish), 15 Seiten
VX4650 Schnellstart Anleitung   LG VX4650 Quick Start Guide, 26 Seiten
55GA6400 Energienachweis   LG 55GA6400 Energy Guide, 1 Seiten
55EA8800 Installationshandbuch   LG 55EA8800 Installation Manual, 16 Seiten
L2323T Bedienungsanleitung   LG L2323T User's Manual, 44 Seiten
WM4070HVA Energienachweis   LG WM4070HVA Energy Guide, 1 Seiten
LFC22770SB Energienachweis   LG LFC22770SB Energy Guide, 1 Seiten
MN240 Bedienungsanleitung    LG MN240 Imprint Manual, 131 Seiten
VS660 Schnellstart Anleitung   LG VS660 Quick Start Guide (Spanish), 36 Seiten
LFX25950SB Bedienungshandbuch   LG LFX25950SB Owner's Manual, 40 Seiten
D959 Spezifikationsblatt   LG D959 Specification Sheet (Spanish), 1 Seiten
VS450PP Datenblatt   LG VS450PP Data Sheet, 2 Seiten
LDS5040BB Energienachweis   LG LDS5040BB Energy Guide, 1 Seiten
LP1214GXR Handbuch   LG LP1214GXR Product manual, 2 Seiten