Nortel Networks 1000 - Manual (Page 647)

Functional description 647
•
provide 600-ohms termination impedance (4-wire configuration)
• provide pad control for 2-wire and 4-wire facility connections
• enable trunk type and function to be configured on a per-port basis in
software
• provide isolation of foreign potentials from transmission and signaling
circuit
• provide software control of A-Law and µ-Law modes
•
support loopback of pulse code modulation (PCM) signals to DS-30X
for diagnostic purposes
The E and M Trunk card passes voice and signaling data over DS-30X
loops, and maintenance data over the card LAN link.
The E and M Trunk card contains four identical and independently
configurable trunk interface units (also referred to as circuits). Each
unit provides impedance matching and a balance network in a signal
transformer/analog hybrid circuit. Also provided are relays for placing
outgoing call signaling onto the trunk. Signal detection circuits monitor
incoming call signaling. A Codec performs A/D and D/A conversion of
trunk analog voiceband signals to digital PCM signals.
The four units on the card can operate in the A-Law or the µ-Law
companding mode. The mode is selected by making service change
entries. Each unit can be independently configured for 2-wire E and M,
4-wire E and M, and paging trunk types. The trunk type is selected by
service change entries and jumper strap settings. All units on the card can
perform the following features:
•
convert transmission signals from analog-to-digital and digital-to-analog
•
provide outpulsing on the card: make/break ratios are defined in
software and downloaded at power-up and by software command
• provide 600-ohm balance and termination impedance (2-wire
configuration)
• provide 600-ohm termination impedance (4-wire configuration)
• provide pad control for 2-wire and 4-wire facility connections
•
allow trunk type and function to be configured on a per port basis in
software
•
provide isolation of foreign potentials from transmission and signaling
circuit
Nortel Communication Server 1000
Circuit Card Reference
NN43001-311 02.06 Standard
27 August 2008
Copyright © 2003-2008 Nortel Networks
.