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DS3 I/O Rear Module
Plexus 9000 Planning and Engineering Guide
Issue 3, April 23, 2004
Section 130-120-5500
5-146
Telica,
Inc
5.12.3 Theory
of
Operation
provides a block diagram or the rear DS-3 IOM and is
described in the following paragraphs.
Front Card
Protection Bus
MID
PLANE
DS3-IOM Rear
RX
Relay
Transformer
From Front Card
From Protection Bus
TX
Relay
Transformer
P250-AA
11-08-00
EE Prom
Figure 5.12-2. Block Diagram of Rear DS-3 IOM
5.12.3.1 Power
Each DS-3 I/O rear module receives its local voltages (5V, 3V, etc.) from
the front IOM that has the DC-to-DC converter for converting the -48
volts from the backplane.
5.12.3.2 Interface
Protection
Buses
Module protection is accomplished by the midplane design where the line
inputs can be routed from the working module to the protection module.
This is performed by relays on the working module that either connect the
signals straight though to the front module, or connect them onto the mid-
plane and the protection bus. The rear protection module picks the signals
off the midplane and routes them to the front protection module.
5.12.3.3 EEPROM
An EEPROM that contains the CLEI code for the module is located on the
module. All modules have a CLEI code so that missing and incompatible
replaceable equipment can be alarmed. The CLEI code of the working
module is BA9IB80AAA and the CLEI code of the protection module is
BA9IB90AAA.