Data flow control arrangement for local area network

A local area data distribution system, comprising

• a central virtual circuit switch connected as a central node to a plurality of data distribution systems each joined independently to the virtual circuit switch in a star network configuration,
• at least one of the data distribution systems comprising;
• a bidirectional data transmission bus,
• a means for controlling data flow connected to the data transmission bus and to the central virtual circuit switch and including local virtual circuit switching means for controlling local data traffic flow to and from addressable entities attached to the bidirectional data transmission bus, and
• the addressable entities including station units each having a unique destination address and operative for coupling data processing devices to the bidirectional data transmission bus and further including means for resolving conflict in more than one station unit simultaneously attempting to access the bidirectional data transmission bus to apply data thereto;

A digital data communication system comprising;

• a plurality of bidirectional communication busses each providing two-way switched packet data communication between a plurality of data processing devices connected thereto,
• each said data processing device including means for resolving conflicts between more than one of said devices attempting to access the connected bus at the same time,
• means for connecting subsets of said busses to a communications hub for providing virtual circuit communication between the different ones of each said subset of busses connected to said hub, and
• means, including a virtual circuit switch, for connecting all of said hubs to each other and to other data communications systems.

A local area data distribution system, comprising:

• a bidirectional data transmission bus,
• first and second stations connected to the bidirectional data transmission bus, each station including;
• means for transmitting and receiving data, data storage means for accommodating differing input and output data rates, a unique address and connecting means for accepting a data processing device;
• a bus termination hub, including;
• a bus master control connected to the data transmission bus, a data trunk for facilitating a data transmission connection to external data handling entities, local virtual circuit switching means, and bus monitoring means for monitoring an operational status of the bidirectional data transmission bus and the first and second station connected thereto and including means for polling a status of each station connected to the data transmission bus;
• the bus master control including data drive and receive means and data buffering means for accommodating differing input and output data rates,
• the local virtual circuit switching means being operative for controlling data flow between the first and second station and between the first and second stations and an external data handling entity.

A local area data distribution system, comprising:

• a first bidirectional data transmission bus,
• a second bidirectional data transmission bus,
• a third bidirectional data transmission bus,
• first and second stations connected to the first bidirectional data transmission bus, third and fourth stations connected to the second bidirectional data transmission bus, fifth and sixth stations connected to the third bidirectional data transmission bus, each station including;
• means for transmitting and receiving data, data storage means for accommodating differing input and output data rates, a unique address and connecting means for accepting a data processing device;
• a first bus termination hub, including;
• a first bus master control connected to the first bidirectional data transmission bus, a second bus master control connected to the second bidirectional data transmission bus, a first data trunk for facilitating a data transmission connection to external data handling entities, first local virtual circuit switching means, and bus monitoring means for monitoring an operational status of the first and second bidirectional data transmission busses and monitoring by polling the first, second, third and fourth stations connected thereto, a first trunk connecting circuit including a first output connection and data retention means for accommodating differing input and output data rates;
• a second bus termination hub, including;
• a third bus master control connected to the third bidirectional data transmission bus, a second data trunk for facilitating a data transmission connection to external data handling entitites, second local virtual circuit means, and bus monitoring measns for monitoring an operational status of the third bidirectional data transmission bus and monitoring by polling the fifth and sixth stations connected thereto, a second trunk connecting circuit including a second output connection and data retention means for accommodating differing input and output data rates;
• the first and second bus master controls each including data drive and receive means and data buffering means for accommodating differing input and output data rates,
• the first local virtual circuit switching means being operative for controlling data flow between one of the first, second third and fourth stations the first and second bidirectional data transmission busses and an external data handling entity, and the second local virtual circuit switching means being operative for controlling data flow between one of the fifth and sixth stations and the external data handling entity;
• the external data handling entity including a central virtual circuit switch node connected to the first and sercond trunks and operative for controlling data flow between the first and second bus termination hubs.

A local area data distribution system wherein data flow is in packet format, comprising:

• a bidirectional data transmission bus,
• first and second stations connected to the bidirectional data transmission bus, each station including;
• means for transmitting and receiving data, data storage means for accommodating differing input and output data rates, a unique address and connecting means for acepting a data processing device;
• a bus termination hub, including;
• a bus master control connected to the data transmission bus, a data trunk for facilitating a data transmission connection to external data handling entities, local virtual circuit switching means and bus monitoring means for monitoring an operational status of the bidirectional data transmission bus and the first and second station connected thereto;
• the bus master control including data drive and receive means and data buffering means for acommodating differing input and output data rates,
• the local virtual circuit switching means being operative for controlling data flow between the first and second station and between the first and second stations and an external data handling entity, and
• each data packet including a first bit for providing synchronization between the bus master control and a connecting station and a second bit for specifying direction of data flow between a bus master and a connecting station.

A local area data distribution system for transmitting data flow in a packet format, comprising

• a first bidirectional data transmission bus,
• a second bidirectional data transmission bus,
• a third bidirectional data transmission bus,
• first and sseocnd stations connected to the first bidirectional data transmission bus, third and fourth stations connected to the second bidirectional data transmission bus, fifth and sixth stations connected to the third bidirectional data transmission bus, each station including;
• means for transmitting and receiving data, data storage means for accommodating differing input and output data rates, a unique address and connecting means for acepting a data processing device;
• a first bus termination hub, including;
• a first bus master control connected to the first bidirectional data transmission bus, a second bus master control connected to the second bidirectional data transmission bus, a first data trunk for facilitating a data transmission connection to external data handling entities, first local virtual sitching means including address translation circuitry, and bus monitoring means for monitoring an operational status of the first and second bidirectional data transmission busses and the first, second, third and fourth, stations connected thereto, a first trunk connecting circuit including a first output connection and data retention means for accommodating differing input and output data rates;
• a second bus termination hub, including;
• a third bus master control connected to the third bidirectional data transmission bus, a second data trunk for facilitating a data transmission connection to externl data handling entities, second local virtual circuit switching means including address translation circuitry, and bus monitoring means for monitoring an operational status of the third bidirectional data transmission bus and the fifth and sixth stations connected thereto, a second trunk connecting circuit including a second output connection and data retention lmeans for accomodating differing input and output data rates;
• the first and second bus master controls each including data drive and receive means and data buffering means for accommodating differing input and output data rates,
• the first local virtual circuit switching means being operative for controlling data flow between one of the first, second, third and fourth stations the first and second bidirectional data transmission busses and an external data handling entity, and the second local virtual circuit switching means being operative for controlling data flow between one of the fifth and sixth stations and the external data handling entity;
• the external data handling entity including a central virtual circuit switch node connected to the first and second trunks and operative for controlling data flow between the first and second bus termination hubs;
• whereby each packet includes a first bit for providing synchronization between the bus master control and a connecting station and a second bit for specifying direction of data flow between a bus master control means and a connecting station.

A local area data distribution system, comprising:

• a bidirectional data transmission bus,
• first and second stations connected to the bidirectional data transmission bus, each station including;
• means for transmitting and receiving data, data storage means for accommodating differing input and output data rates, a unique address and connecting means for accepting a data processing device;
• a bus termination hub, including;
• a bus master control connected to the data transmission bus, a data trunk for facilitating a data transmission connection to external data handling entities, local virtual circuit switching means and bus monitoring means for monitoring a operational status of the bidirectional data transmission bus and the first and second station connected thereto and operative for disconnecting and identifying a faulty bidirectional data transmission bus or one having a faulty station connected to it;
• the bus master control including data drive and receive means and data buffering means for accommodating differing input and output data rates,
• the local virtual circuit switching means being operative for controlling data flow between the first and second station and between the first and second stations and an external data handling entity.

A local area ata distribution system, comprising:

• a first bidirectional data transmission bus,
• a second bidirectional ata transmission bus,
• a third bidirectional data transmission bus,
• first and second staitons connected to the first bidirectional data transmission bus, third and fourth stations connected to the second bidirectional data transmission bus, fifth and sixth stations connected to the third bidirectional data transmission bus, each station including;
• means for transmitting and receiving data, data storage means for accommodating differing inlput and output data rates;
• a unique address and connecting means for accepting a data processing device;
• a first bus termination hub, including;
• a first bus master control connected to the first bidirectional data transmission bus, a second bus master control connected to the second bidirectional data transmission bus, a first data trunk for facilitating a data transmission connection to external data handling entities, first local virtual circuit switching mesans, and bus monitoring means for monitoring an operational status of the first and second bidirectional data transmission busses and the first, second, third and fourth, stations connected thereto and further being operative for disconnecting and identifying a faulty bidirectional data transmission bus or one having a faulty station connected to it, a first trunk connecting circuit including a first output connection and data retention means for accommodating differing input and output data rates;
• a second bus termination hub, including;
• a third bus master control connected to the third bidirectional data transmission bus, a second data trunk for facilitating a data tansmission connection to external data handling entities, secon local virtual circuit switching means, and bus monitoring means for monitoring an operational status of the third bidirectional data transmission bus and the fifth and sixth stations connected thereto and further being operative for disconnecting and identifying a faulty bidirectional data transmission bus or one having a faulty station connected to it, a second trunk connecting circuit including a second output connection and data retention means for accommodating differing input and output data rates;
• a trunk for data transmission connected to the first and second output connections;
• the first and second bus master controls each including data drive and receive means and data buffering means for accommodating differing input and output data rates,
• the first local virtual circuit switching means being opetive for controlling data flow between one of the first, second, third and fourth stations that first and second bidirectional data transmission busses and an external data handling entity, and the second local virtual circuit switching means being operative for controlling data flow between one of the fifth an sixth stations and the external ata handling entity;
• the external data handling entity including a central virtual circuit switch node connected to the first and second trunks and operative for controlling data flow between the first and second bus termination hubs.

A local area data distribution system wherein data flow is in a form of data packets, comprising:

• a data packet format in which each data packet includes synchronizing information, directional information and address information,
• a central virtual circuit switch connected as a central node to a plurality of data distribution systems each joined independently to the virtual circuit switch in a star network configuration,
• at least one of the data distribution systems comprising;
• a bidirectional data transmission bus,
• a means for controlling data flow connected to the data transmission bus and to the central virutal circuit switch and including local virtual circuit switching measns for controlling local data traffic flow to and from addressable entities attached to the bidirectional data transmission bus and including means for translating and converting source address information into a specific destination address, and
• the addressable entities including station units each having a unique destination address and operative for coupling data processing devices to the bidirectional data bus.

A system for local distribution of data packets, comprising:

• a bidirectional data transmission bus including a plurality of passive data outlets.
• at least a first and second data station connected to first and second ones of the passive data outlets, each data station having a unique address, and input means for accepting a data processing device,
• a data trunk for connecting to an external data handling entity,
• a bus termination hub connect.RTM.d for interconnecting the ata trunk and the bidirectional data transmission bus and including a bus master control an local virtual circuit switch for switching data between the data trunk and the bus master control,
• the bus master control including a data driver, a data receiver, and data buffering apparatus for accommodating differing data rates between the data trunk and the bidirectional data transmission bus and a means for applying synchronization signals to the bidirectional data transmission bus, and means for polling a status of stations connected to the bidirectional data transmission
• the first and second stations each including a data driver, a data receiver and data buffering apparatus for accommodating differing data rates between the data processing device and the bidirectional data transmission bus;
• synchronization signal response means and means for determining if the bidirectional data transmission bus is in a mode transmitting data to station or in a mode receiving data from stations.