MARINE RADIO CO.,LTD.
주/선박무선
Subject : Auto Exchanger Page : (38 / 44)
Date : 2010.10.06 Doc. : Matex-2000_ENG(Rev. 1.0)
(QAS-ADD-008/0/09.09.25) manual\pabx\matex-2000\Matex-2000_eng.doc
(
MARINE RADIO CO., LTD.)
MRC
2. Explanation of Circuit
2.1 Configuration of System
An auto-exchanger for the MATEX-2000series includes power source unit, switching regulator
unit, CPU board, dial tone board, trunk board, I/O switching board, display board etc.
1. Except for switching regular unit and display board, the main devices make replacement
and maintenance easily because they support plug-in.
The following figure shows the signal flow of each device:
2.2 CPU Board
The CPU board controls the overall system. 8085 Micro-Processor performs all functions by program in
system ROM. Timer sets time for morning call, and CPU reads time data and uses them as a variety of time
information. This time information is operated by built-in battery even during power failure. Also, it is
transmitted to display board through buffer. The Watch Dog circuit is automatically initialized if the failure is
generated in program, so it recovers the system normally. CPU monitors the selected I/O board through card
select port, address bus and control signal port. At this time, if any subscriber picks up the handset, it is
detected by data bus and operated in order of program. The following figure shows the detailed flow of CPU
board:
To Next Page
Loading...