Abstract: A star coupler for serial bus systems operates in compliance with the carrier sense multiple access (CSMA) method. The star coupler connects a plurality of individual bus systems to corresponding T-drivers and associated logic circuits, so that arbitration is performed within the total bus system in which all individual bus systems are included. Feedback suppression is used to assure unidirectional data flow, while error detection is combined with switching logic to disable faulty individual bus systems without affecting the other connected individual bus systems.

Abstract: A method of dispatching documents, wherein the basic idea is to first convert the documents from a customer-specific data format to a standardization data format, and only then to decide by means of a decision logic using the document in the standardized data format, whether the document is further transmitted to the recipient as an electronic document, or whether it is converted from the standardized to a postal data format in a converter station. The converter station then dispatches the document to a postal service printing center in the area where the recipient is located. There the document is printed out and directed for delivery by postal service personnel.

Abstract: A communications system (10) is provided which comprises a plurality of network hubs (12), (14), and (16). Network hubs (12), (14), and (16) are interconnected through a communications network (18). The system (10) interconnects messaging systems (24), (26), (28), (30), (32), (34), (36), (40), (42) and (44) having disparate capabilities and using disparate communications protocols. The network hubs use numbers of connection processors (52) and (54) to interact with the messaging systems. A hub database (68) and message store (58) are used to store control information and messaging information within the network hubs. A network processor (60) is used to interact with other hubs within the communications system (10). A message router (72), connection manager (74), data replicator (76), and an administrative event manager (78) are used to control the operations of the hub in processing a message.

Abstract: A method and a facility for communication between packet mode supporting units interconnected in the core of a communications installation by point-to-point links that are physically structured and time governed in identical manner, a packet being transmitted between two packet mode support units of the installation after the unit desiring to transmit has previously sent a request to the destination unit and the destination unit has responded with a corresponding acknowledgment. The communications facility constitutes a distributed type asynchronous switch in which each packet mode support unit includes a packet communication circuit to which the point-to-point links terminating at the unit are connected via a switching module. The communication circuit conditions each of the packets that is to be transmitted to another packet mode supporting unit of the installation in the form of a sequence of cells, and also performs inverse conditioning.

Abstract: A frame-structured bus system, particularly for a local operation network for automotive applications, is disclosed in which a plurality of bus stations share a data bus, and in which one of the bus stations generates a sequence of data frames of constant bit length. Each data frame includes an isochronous frame module and an asynchronous frame module, and the division of each data frame into the isochronous and asynchronous frame modules is dynamically variable. The message transmitted by a station is passed through a central star coupler to all stations.

Abstract: Apparatus for monitoring and displaying the status of a local area network. The network includes a hub with ports for connection to various data terminal equipment in a star configuration and for connection to other hubs of the network. The hubs each have different types of plug-in modules which have ports for connecting the hub to different types of network cable such as fiber optic cable, unshielded twisted pair cable and shielded twisted pair cable. Information is automatically provided to a control console identifying the types of modules and the location of the modules in the hub so that an image of the actual hub can be displayed on the screen of the control console. The actual hub image shows the location and types of modules installed in the hub. In addition, information regarding the connection of each of the hubs to other hubs of the network is obtained and provided to the control console.