Microprocessor; Signalling And Control; Signalling Interface - Northern Telecom NT5K17 Description

1-2 NT5K17 Direct Dialing Inward Trunk Card

Microprocessor

Signalling and control

Signalling interface

553-3001-173 UK Trunk cards description
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• provides for loss pads appropriate to 3 dB, 6 dB and 8 dB Public
Switched Telephone Network (PSTN) lines as governed by the UK
System Loss plan
• provides termination impedance to match the UK three-component
complex network
• provides transhybrid balance matching against the UK complex
impedance
• provides Analog-to-Digital and Digital-to-Analog call path losses for
DDI trunk units, values downloadable in the initial configuration
stage.
The NT5K17 DDI trunk card is equipped with an Intel 8052-type
microprocessor that controls card operation. The microprocessor also
provides the communication function for the card.
The NT5K17 DDI trunk card communicates with the controller card
through a serial communication link. Features provided through the serial
link include:
• card-identification
• self-test status reporting
• status reporting to the controller card
• maintenance diagnostics.
The signalling and control portion of the NT5K17 DDI trunk card operates
with the Central Processing Unit (CPU) to control card hardware. The card
receives messages from the CPU over a signalling channel and returns
status information to the CPU over the same channel. The signalling and
control portion of the card provides the means for analog loop terminations
to establish, supervise, and take-down call connections.
Trunk signalling messages are three bytes in length. The messages are
transmitted in channel zero of the DS-30X in A10 format.