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NWA-008845-001 Rev.5.0
32ch1008.fm
MESSAGE CENTER INTERFACE (MCI)
SYSTEM OUTLINE
The Message Center Interface (MCI) provides an interface with a customer supplied Voice Mail System
(VMS) which can send Message Waiting lamp control data to the PBX.
The MCI can provide the following operations.
• Incoming call information is sent to the VMS when a call terminates to the VMS.
• Control of Message Waiting lamps is based on information sent from the VMS.
The MCI interface is a half duplex EIA-RS232C asynchronous data link that operates under a specific
message protocol and format.
The PBX can provide two kinds of MCI. One is the RS-232C interface on the MP card, and the other is
the RS-232C interface on the AP00 card.
The system outline of the MCI is shown below.
(1) MCI with MP
The Main Processor (MP) is required to make a data link with a customer supplied VMS and the
analog line circuit (LC) to interface with the VMS.
• MP card:
The MP stores call information for stations, and provides the RS-232C ports for a VMS.
The MP keeps supervising the status of the VMS. If the VMS is not ready for information
receiving (Busy Status), the MP temporarily stores the call information into its internal memory.
The MP stores call information of a maximum of 15 calls.
• LC card:
The LC is used for the VMS stations. The UCD or Station Hunting feature is usually provided with
the VMS stations.
MESSAGE CENTER INTERFACE (MCI)
SYSTEM OUTLINE