Passive bus system for decentrally organized multi-computer systems
AssigneeSiemens Aktiengesellschaft
InventorsAnton Sauer, Hans H. Witte
Life of this patent
Estimating the term…
Abstract
A passive bus system for decentrally structured multi-computer systems, particularly multi-microcomputer systems, allows execution of a bit-serial information exchange between the individual computers of the system achieving the bandwidth required for high transmission speeds with simple and reliable means, capable of decentralized monitoring and control. Exclusively optical transmission means is employed for all data exchange operations in a communications level shared by all of the function units of the multi-computer system, exclusively decentralized control devices are individually allocated to the function units for control of the bus system seizure.
Claims23
In a decentrally organized multi-computer system incorporating a plurality of function units, a passive bus communication system comprising an internal communication function unit for carrying on all data exchange operations between individual ones of said function units, said passive bus communications system employing exclusively optical transmission means, means associated individually with a plurality of said function units for the control of said bus system, a plurality of optical transmitter-receivers individually allocated to said function units and a light wave guide for optically connecting said optical transmitter-receivers to all other optical transmitter-receivers, said light wave guide being individually allocated to each said transmitter-receiver by means of an optical mixer, said optical mixer comprising a bidirectional mixer operating as the central mixer in a central level of the passive bus system, and including a plurality of transmission-reception lines each of which is respectively connected between the branching point of a branching unit and one of a plurality of terminals of a first group of terminals of the central mixer, a plurality of auxiliary computers, means for connecting said auxiliary computers to terminals of said branching units, and means for connecting at least one function unit directly to a plurality of terminals of a second group of terminals of the central mixer without using a branching unit.
A method for operating a passive bus system for a decentrally organized multi-bus computer system incorporating exclusively optical transmission means for all data exchange operations between plural function units comprising the steps of:
- providing address information in each of the information packets to be transmitted, said address information consisting of two addresses, namely, a source address representing the information source and a destination address representing the information destination;
- transmitting, from the transmission part of the transmitter-receiver of a designated function unit, information packets containing said address information to all of the function units comprising said computer system;
- receiving in the reception part of the transmitter-receiver of said designated function unit the information packets transmitted by the transmission part of the transmitter-receiver of said designated function unit;
- checking a received information packet in the reception part as to non-falsification by comparing it with the corresponding information packet still available in the transmission part;
- interrupting further transmission of information packets upon the detection of erroneously received address information;
- repeating the transmitting operation with successively longer pauses between the information packets until the reception part has received non-erroneous information;
- receiving in the reception part of the transmitter-receiver of the remaining function units all transmitted information packets;
- checking the received address information by each said remaining function unit by comparing the destination address of the received address information with the address associated with that function unit;
- accepting the information contained in the information packet whenever the destination address of the received address information matches the address of the function unit;
- and
- cancelling the received information whenever the destination address of the received address information does not match the address of the function unit.
Dependencies are inferred from the claim text.