ZyXEL Communications Multi-service Access Platform MSAP2000 - Manual (Page 126)

7. Product Specification
MSAP2000 Technical Manual V3.0 7-19
7.8. Expansion Processing Module (EPM)
Overview
The Expansion Processing Module (EPM) co-works with the Expansion
Link Module (ELM) to provide capacity expansion for a single node.
The EPM is installed within the extension shelf, whereas the ELM is
installed within the main shelf.
The EPM provides the extension shelf’s with a synchronized clock, and
also converts and transmits the control commands sent from the Main
Processing Module (MPM).
Features
And
Benefits
„ Panel LEDS indicate status, faults, alarms, and network connection
„ Timing recovery circuit, with ultra-low jitter
„ Simplified insertion and monitoring procedures for STM-1 Overhead
Byte
„ Protection Switch functions
„ Clock synchronization recovery, and excellent phase lock loop
technologies
„ Alarm and fault monitoring and reporting
„ Digital cross-connection for all STM-1 Timeslots
„ Use of non-volatile memory devices for storage of performance data
Function
Diagram
Application
When more than one shelf is needed, installation of EPM in the
expansion shelf is needed. A corresponding ELM must be installed in
the main shelf and link with EPM using a multi-mode fiber patch-cord.
ELM MPM Module
Local node communication
Module EPM Module
Local node communication