Card Interfaces; Card Control Functions - Nortel Enterprise 1000 Reference Manual

Page 50 of 236 Analog Trunk Cards - NT8D14 Universal Trunk Card

Card interfaces

Card control functions

553-3023-211 Standard 1.00 June 2001
The universal trunk card passes voice and signaling data over DS-30X loops,
and maintenance data over the card LAN link.
The universal trunk card contains eight 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. Two CODECs are provided for performing A/D and D/A
conversion of trunk analog voiceband signals to digital PCM signals. Each
CODEC supports four trunk interface units. The following features are
common to all units on the card:
• trunk type configurable on a per unit basis
• terminating impedance (600 or 900 ohms) selectable on a per unit basis
(minimum vintage BA)
• balance impedance (600 or 900 ohms or complex impedance network)
selectable on a per unit basis (minimum vintage BA)
• control signals provided for RAN and paging equipment
• loopback of PCM signals received from trunk facility over DS-30X
network loop for diagnostic purposes
• switchable pads for transmission loss control
Control functions are provided by a microcontroller, a card LAN interface,
and signaling and control circuits on the universal trunk card.
Microcontroller
The universal trunk card contains a microcontroller that controls the internal
operation of the card and the serial card LAN link to the controller card. The
microcontroller controls the following:
• reporting to the CE CPU through the card LAN link:
— card identification (card type, vintage, and serial number)
— firmware version