Nortel Networks Circuit Card 311 - Manual (Page 894)

894 NTAK10 2.0 Mb DTI card
Carrier interface
Tx Direction
The HDB3 encoded multiplexer output is sent to the output selector, which
selects the PCM/Data output or the looped around far end data. The HDB3
is converted from digital to AMI and sent to the carrier. A transformer
provides isolation and impedance matching (75 ohms or 120 ohms).
The HDB3 encoded multiplexer output is fed to the output selector, which
selects the PCM/Data output or the looped around far end data. The
HDB3 is converted from digital to AMI and fed to the carrier. A transformer
provides isolation and impedance matching (75 ohms or 120 ohms).
The HDB3 encoded multiplexer output is sent to the output selector, which
selects the PCM/Data output or the looped around far end data. The HDB3
is converted from digital to AMI and sent to the carrier. A transformer
provides isolation and impedance matching (75 ohms or 120 ohms).
Rx Direction
The AMI data of the carrier is converted to digital and fed to the input
selector as well as the output selector for far end loopback. Clock recovery
circuitry within the receiving device extracts the 2.0 MHz clock. This clock
generates the frame and multiframe count and sends them to the clock
controller as a reference.The AMI data of the carrier is converted to digital
and fed to the input selector as well as the output selector for far end
loopback. Clock recovery circuitry within the receiving device extracts the
2.0 MHz clock. This clock is used to generate the frame and multiframe
count and is sent to the clock controller as a reference.
The AMI data of the carrier is converted to digital and fed to the input selector
as well as the output selector for far end loopback. Clock recovery circuitry
within the receiving device extracts the 2.0 MHz clock. This clock generates
the frame and multiframe count and sends them to the clock controller as a
Clock controller interface
The recovered clock from the external digital facility is provided to the clock
controller through the backplane-to-clock controller interface. Depending
upon the state of the clock controller (switched on or off), the clock controller
interface, in conjunction with software, enables or disables the appropriate
reference clock source.
The clock-controller circuitry on NTAK10 is identical to that of the NTAK20.
While several DTI/PRI packs can exist in one system, only one clock
controller can be activated. All other DTI/PRI clock controllers must be
switched off.
Nortel Communication Server 1000
Circuit Card Reference
NN43001-311 01.04 Standard
Release 5.0 23 May 2008
Copyright © 2003-2008, Nortel Networks
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