EP0074672A2
Expired / Lapsed
EP
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Asynchronous data bus system
Assignee: FMC Corp
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Filing: 1982-09-16
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Granted: —
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Expires: 2002-09-16
Abstract
Abstract A data bus system includes a plurality of interconnected active terminals which receive data from one terminal and re-transmit it or transmit new data to a new terminal. The data is in seria p digital form and takes one of a known group of message component formats. The messages contain a code identifying the format and the message may be of any arbitrary length. An access window signal is transmitted from terminal to terminal along a closed transmission path, which begins and ends at each terminal, as long as the system is available for transmission by one of the terminals. A terminal receiving the access window signal which has a transmission to place on the transmission path removes or "captures" the access window signal and subsequently opens the loop at the "capturing" terminal preparatory to transmitting data on the transmission path. The terminal is said to be in the transmit access mode when configured to transmit data along the transmission path and to be in the relay mode when configured to re-transmit data along the transmission path. In one embodiment of the invention the transmission path is dual and a transmitter and receiver is provided in each terminal for each transmission path. The paths extend from a separate transmitter in one terminal to a separate receiver in an adjacent terminal so that two continuous loops are formed as the transmission paths serially communicate with each terminal in the system. In this latter embodiment the system may be configured by a microprocessor to enter either a diagnostic mode, wherein the system is configured in the most efficient arrangement considering possible terminal or transmission path casualties, or a user access mode after the most desirable system configuration is implemented and users in communication with various ones of the terminals are to be served. It should be noted that in the diagnostic mode a system functions synchronously as directed by a controller terminal, while in the user access mode the system functions asynchronously.
Inventors
- 👤 Keith S. Champlin
- 👤 George William Miller
- 👤 Ernest Charles Preimesberger
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-29 17:40
CPC Classifications
H; H04; H04L; H04L12/00; H04L12/28; H04L12/42; H04L12/437; H04L12/427; H04L12/433
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
200 words
An asynchronous data communications system wherein a plurality of system users provide data at random intervals and ot random length and wherein system dead time is minimized, comprising a plurality of multiplex terminals.in communication with ones of the system users, a transmitter and a receiver in each of said terminals, a message component path communicating said transmitter in one of said terminals with said receiver in another ot said terminals so tha said path describes a continuous loop extending from and returning to each of said terminals, means in each of said multiplex terminals for accepting data from said receiver and for providing said data to one of the system users in communication therewith, means in each of said multiplex terminals for transferring data to said transmitter from one of the system users in communication therewith, means in each of said multiplex terminals for controlling said terminal to operate in a transmit access moae so that data is transmitted thereby from a user in communication therewith and to operate in a relay mode so that data is relayed trom said receiver to said transmitter for retransmittal along said path to a user in communication with another of said multiplex terminals.
Claim 2
Dependent Claim
200 words
An asynchronous data communications system wherein a plurality of system users provide data at random intervals and ot random length and wherein system dead time is minimized, comprising a plurality of multiplex terminals.in communication with ones of the system users, a transmitter and a receiver in each of said terminals, a message component path communicating said transmitter in one of said terminals with said receiver in another ot said terminals so tha said path describes a continuous loop extending from and returning to each of said terminals, means in each of said multiplex terminals for accepting data from said receiver and for providing said data to one of the system users in communication therewith, means in each of said multiplex terminals for transferring data to said transmitter from one of the system users in communication therewith, means in each of said multiplex terminals for controlling said terminal to operate in a transmit access moae so that data is transmitted thereby from a user in communication therewith and to operate in a relay mode so that data is relayed trom said receiver to said transmitter for retransmittal along said path to a user in communication with another of said multiplex terminals.
Claim 3
Dependent Claim
68 words
A communications system as in claim 1 wherein said means for transrerring data includes means for providing terminal broadcast data and wherein said means for accepting data includes means for accepting terminal broadcast data, said means for providing and accepting broadcast data communicating with said means for controlling, whereby said means for controlling in each multiplex terminal may communicate with said same means in every other multiplex terminal.
Claim 4
Dependent Claim
40 words
A communications system as in claim 1 wherein the data is in one of a predetermined number of data formats having predetermined identifying codes, and wherein said means for accepting data includes a format decoder, whereby format identification is established.
Claim 5
Dependent Claim
73 words
A communications system as in claim 1 wherein said means for controlling includes means for providing an initiation signal indicative of system availability for data transmission, and wherein said means for transferring data includes means coupled to said initiation signal for providing a system access signal at the termination of a data transmission, whereby each multiplex terminal in sequence in said continuous loop is apprised that the system is available for data transmission.
Claim 6
Dependent Claim
64 words
A communications system as in claim 4 wherein said means for controlling comprises means for capturing said system access signal when said means for transferring in the receiving multiplex terminal has data ready for transmittal, and means for opening said continuous loop at the receiving terminal in response to capture of said access signal and for communicating said means for transferring with said transmitter.
Claim 7
Dependent Claim
88 words
A communications system as in claim 1 wherein said transmitter and said receiver comprise dual transmitters and receivers and wherein said message component path comprises dual paths each extending from a separate transmitter in one multiplex terminal to a separate receiver in another multiplex terminal, whereby said continuous loop comprises a pair of parallel loops serially connecting said multiplex terminals, and means included in said means for controlling for alternately configuring said plurality of multiplex terminals all in a diagnostic mode and all in a user access mode.
Claim 8
Dependent Claim
74 words
A communications system as in claim 6 wherein said means for controlling includes a microprocessor and means for cross coupling a receiver in one of said parallel loops with a transmitter in the other of said loops in each terminal, so that said microprocessor may analyze the status of each loop and configure a hybrid loop when required in accordance with microprocessor instructions when all of said multiplex terminals are in said diagnostic mode.
Claim 9
Dependent Claim
208 words
A communications system for conveying messages of random length from system users in a sequence in accordance with the position of the user in the system and the time at which the message is ready for transmission while minimizing overhead, comprising at least two terminals each configurable in a relay and in a transmit access mode, a message conducting path extending from each terminal to another terminal so that said terminals are serially connected in a closed loop, means at each terminal for receiving messages conducted along said message path from an adjacent terminal in said loop, means in eacn terminal for transmitting messages along said message path to an adjacent terminal in said loop, means in each terminal for coupling newly generated messages to said means for transmitting, means in communication with-said means for coupling for selectively generating and joining to newly generated messages a signal indicative of system availability for message transmission, means included in each terminal coupled between said means for receiving and means for transmitting for removing said system availability signal from a received message when said receiving terminal has a message to transmit, and means responsive to removal of said system availability signal for configuring said receiving terminal in said transmit access mode.
Claim 10
Dependent Claim
208 words
A communications system for conveying messages of random length from system users in a sequence in accordance with the position of the user in the system and the time at which the message is ready for transmission while minimizing overhead, comprising at least two terminals each configurable in a relay and in a transmit access mode, a message conducting path extending from each terminal to another terminal so that said terminals are serially connected in a closed loop, means at each terminal for receiving messages conducted along said message path from an adjacent terminal in said loop, means in eacn terminal for transmitting messages along said message path to an adjacent terminal in said loop, means in each terminal for coupling newly generated messages to said means for transmitting, means in communication with-said means for coupling for selectively generating and joining to newly generated messages a signal indicative of system availability for message transmission, means included in each terminal coupled between said means for receiving and means for transmitting for removing said system availability signal from a received message when said receiving terminal has a message to transmit, and means responsive to removal of said system availability signal for configuring said receiving terminal in said transmit access mode.
Claim 11
Dependent Claim
31 words
A communications system as in claim 8 wherein said means for configuring comprises means for closing said'message conducting path in said closed loop through a terminal wnen in said relay mode.
Claim 12
Dependent Claim
66 words
A communications system as in claim 8 wherein said means for transmitting includes means ior providing terminal broadcast messages and wherein said means for receiving includes means for accepting terminal broadcast messages, said means for providing and accepting broadcast messages communicating with said means for configuring, wnereby said last named means in eacn multiplex terminal may communicate with said same means in every other multiplex terminal.
References Cited (Backward Citations)
No citation records indexed.
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