8. ABBREVIATIONS AF- - Access Fault AR- - Action Request CC- - Central Control (CPU, DS, PS) CI- - Command Interpreter CMC- - Central Message Controller CP- - Call Processing CPU- - Central Processor Unit DC- - Device Controller cards (part of IOC) DR- - Diagnostic Request DS- - Data Store FD- - Fault Detection IOC- - Input-Output Controller LM- - Line Module MAP- - Maintenance and Administration Position MMI- - Man-Machine Interface MR- - Manual Request MSIP- - Maintenance Sub-system Interaction Protocol NM- - Network Module NMC- - Network Message Controller ODM- - Office Data Modification PM- - Peripheral Modules (LM, TM) PS- - Program Store SR- - Status Request SS- - Sub-system TL- - Trunk/Line Maintenance TM- - Trunk Module TTY- - Teletype or printer VDU- - Visual Display Unit (c) NORTHERN TELECOM LIMITED, 1978 MAINTENANCE SYSTEM DMS-100/200