US 4,383,137 A · Key telephone system with multiple processor control

Abstract

A key telephone exchange system comprises office line units connected to office lines, terminal units respectively connected to key telephone sets and a main control unit for changing connections between respective office line units and respective terminal units. Each office line unit comprises a first memory device to store data transmitted between the office line unit and an office line, and a first processor for writing and reading data into and out of the first memory device for controlling origination and call requests to and from the office line. Each terminal unit comprises a second memory device adapted to store data transmitted between a terminal unit and a key telephone set, and a second processor for writing and reading data into and out of the second memory device for controlling transmission of data between a terminal unit and a corresponding key telephone set. The main control unit comprises a third memory device for storing states of use of the terminal unit and of the office line unit, and a third processor which sequentially scans data in the first and second memory devices of the terminal unit and of the office line unit and for exchanging connections between the terminal units and the office line units according to data obtained as a result of the scanning.

Claims28

Dependent claims

A key telephone exchange system for enabling connections between office lines and key telephone sets, said system comprising:

a main control unit provided with a processor;
a plurality of office line units provided for respective office lines, each office line unit including a processor, means for detecting a call request and means for seizing an office line;
a plurality of key telephone sets;
and
a plurality of terminal units respectively connected to associated ones of said key telephone sets via voice lines and data lines, each terminal unit including a processor, means for transmitting and receiving data to and from a telephone set, and means for establishing connections;
the processor of said main control unit including means for checking information signals of said office line units and of said terminal units, and means for controlling said office line units and said terminal units in accordance with the results of said checking for establishing connections between said office lines and said key telephone sets and between said key telephone sets.

3 more elements

In a key telephone exchange system of the type comprising office line units connected to office lines, terminal units respectively connected to key telephone sets via voice lines and data lines, and a main control unit for establishing connections between respective office line units and respective terminal units, the improvement wherein each one of said office line units comprises a memory device adapted to store data transmitted between said office line unit and an office line, and a processor for writing and reading data into and out of said memory device for controlling origination and call requests to and from said office line;

wherein each one of said terminal units comprises a memory device adapted to store data transmitted between a terminal unit and a telephone set, and a processor for writing and reading data into and out of said terminal unit memory device for controlling transmission of data between a terminal unit and a corresponding telephone set;
and wherein said main control unit comprises a memory device for storing states of use of said terminal units and said office line units, and a processor for sequentially scanning data in said memory devices of said terminal units and said office line units and for establishing connections between said terminal units and said office line units according to data obtained as a result of the scanning.

A key telephone exchange system comprising:

a main control unit (MCU) provided with a processor;
a plurality of office line units (SLU1-SLUm) corresponding to a plurality of office lines, each of the office line units being provided with a means (DET) for detecting states of said corresponding office lines, a means (HS, hS1) for seizing said office line, a memory (MS) for storing first information from and to said detecting means (DET) and said seizing means (HS, hS1), and a processor (CPUs) for controlling operations of writing and reading said first information to and from said memory (MS), and for controlling operations of said detecting means (DET) and said seizing means (HS, hS1) without depending on said main control unit processor;
a plurality of terminal units (TEU1-TEUn) corresponding to a plurality of key telephone sets (MFT1-MFTn), each of said terminal units being connected to the corresponding key telephone set through a pair of data lines (DL1-DLn) and provided with a means (MODEM, Td) for transmitting and receiving second information to and from the corresponding key telephone set, a memory (Mt) for storing the second information to and from the corresponding key telephone set, and a processor (CPUt) for controlling operation of writing and reading the second information to and from said memory (Mt) and for controlling operations of said second information transmitting and receiving means without depending on said main control unit processor;
and
a means for establishing through a pair of voice lines (VL1-VLn) a connection between one of said office lines and one of said key telephone sets in accordance with a control signal from said main control unit processor;
said main control unit processor having means for sequentially analyzing said office line states using portions of the first information stored in said office line unit memories and portions of the second information stored in said terminal unit memories which are transmitted from said key telephone sets.

3 more elements

Dependencies are inferred from the claim text.

Key telephone system with multiple processor control

Life of this patent

Key telephone system with multiple processor control

Life of this patent

Abstract

Claims28