Passive bus system for decentrally organized multi-computer systems
First Claim
1. 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.
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Accused Products
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.
75 Citations
23 Claims
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1. 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.
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2. The passive bus system according to claim 1, wherein a transmission part and a reception part of all transmitter-receivers are connected via optical transmission lines and optical reception lines to first and second terminals of an optical branching unit, a third terminal of said branching unit being connected via a transmission-reception line to a terminal of the bidirectional mixer.
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3. The passive bus system according to claim 1, wherein single-element transmitter-receivers are individually allocated to said function units, each of said single-element transmitter-receivers being connected to a terminal of said bidirectional mixer via a transmission-reception line individually allocated to said single-element transmitter-receiver.
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4. The passive bus system according to claim 1, wherein said bidirectional mixer functions as the central mixer in a central level of the passive bus system;
- and including a plurality of transmission-reception lines connected to a plurality of terminals of a first group of terminals of the central mixer, each of said transmission-reception lines being connected to a branching unit, a plurality of auxiliary computers each having a transmission part and reception part connected to first and second terminals of one of said branching units, a plurality of unidirectional optical submixers connected to a plurality of terminals of a second group of terminals of the central mixer; and
means for connecting a plurality of said function units to terminals of said submixers.
- and including a plurality of transmission-reception lines connected to a plurality of terminals of a first group of terminals of the central mixer, each of said transmission-reception lines being connected to a branching unit, a plurality of auxiliary computers each having a transmission part and reception part connected to first and second terminals of one of said branching units, a plurality of unidirectional optical submixers connected to a plurality of terminals of a second group of terminals of the central mixer; and
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5. The passive bus system according to claim 4, wherein said unidirectional submixers are connected via bidirectional transmission-reception lines to the central mixer, and including a plurality of branching units connected to said submixers, and means connecting said function units to said central mixer via unidirectional transmission and reception lines, so that a tree structure results for the bus system.
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6. The passive bus system according to claim 5, wherein additional function units are connected with their transmission and reception parts to the central mixer or to at least one submixer, directly via unidirectional transmission and reception lines, so that a hybrid structure results for the bus system.
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7. The passive bus system according to claim 4, wherein the connection of the submixers is provided via at least two transmission or reception lines, whereby a corresponding number of terminals are provided both at the central mixer and at the submixers, to achieve an optimization of the distribution of the light power.
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8. The passive bus system according to claim 1, including at least one function computer having its transmission part connected to a terminal of a first connection side of the unidirectional mixer via a function computer transmission line, and having its reception part connected to a terminal of a second connection side of the unidirectional mixer via a function computer reception line;
- and including at least one auxiliary computer having its transmission part connected to a further junction point of the first connection side of the unidirectional mixer via an auxiliary computer transmission line, and having its reception part connected to a further terminal of the second connection side of the unidirectional mixer via an auxiliary computer reception line.
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9. The passive bus system according to claim 1, wherein all light wave guides comprise a single light wave guide;
- and wherein all data transmission operations are executed by means of serial light pulses in chronological succession.
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10. The passive bus system according to claim 9, wherein said light wave guides are constructed as single-fiber wave guides.
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11. The passive bus system according to claim 9, wherein the light wave guides are constructed as multi-fiber wave guides.
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12. The passive bus system according to claim 1, wherein the transmission part consists of a light emitting diode, and a pre-connected amplifier;
- and wherein the reception part consists of a phototransistor, and a post-connected amplifier.
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13. The passive bus system according to claim 1, wherein the transmission part consists of a light-emitting diode LED, and a pre-connected amplifier;
- and wherein the reception part consists of a photodiode and a post-connected amplifier.
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14. The passive bus system according to claim 1, wherein an individually allocated optical input-output device is provided for each of said function units, each said optical input-output device being coupled to all other input-output devices via an output line and via an input line, and being connected to further devices of its associated function unit via an internal computer bus.
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15. The passive bus system according to claim 9, wherein a control clock is derived from the chronologically successive light pulses of the optical information, means for intermediately storing information bits gained from the individual light pulses and representing electrical character pulses;
- and a clock buffer associated with the optical input-output device, said clock buffer being connected to said intermediate storage means to synchronize the storage and recall of said information bits with the working clock of an associated central processing unit CPU.
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16. The passive bus system according to claim 1, including two optical bus lines, means for transmitting useful data information via the first of the two optical bus lines and means for transmitting diagnostic information via the second of the two optical bus lines for the purpose of error recognition and error localization.
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17. The passive bus system according to claim 1, including two optical bus lines, means for transmitting information representing a test request via the first of the two optical bus lines and means for transmitting information representing a test execution via the second of the two optical bus lines, so that the functionability of the two optical bus lines can be monitored.
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18. The passive bus system according to claim 16, including means for changing over the two optical bus lines, whereby the functions can be interchanged.
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19. 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:
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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.
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20. The method according to claim 19, including the step of transmitting said address information in a code with error detectability, so that an information falsification arising due to a chronological coincidence of two or more transmission operations can be detected.
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21. The method according to claim 20, including the step of employing a code with a constant, prescribed hamming distance between the binary words as the code with error detectability.
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22. The method according to claim 20, including the steps of initiating an interrupt procedure for inputting a received information via an internal computer bus into a central processing unit only when an addressing operation is terminated, to allow a complete decoupling of the input line from the central processing unit, and allowing specific functions of the central processing unit to have priority over an input of said received information.
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23. The method according to claim 19, including the step of executing an information transmission or a data transfer directly between memories of two or more computers, so that the associated central processing units are disconnected from the internal computer bus, whereby they can sequence priority processing operations or remain in idle condition.
Specification