US3732543A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Loop switching teleprocessing method and system using switching interface
Assignee: International Business Machines Corp
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Filing: 1971-06-30
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Granted: 1973-05-08
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Expires: 1991-06-30
Abstract
Abstract A method and system is described for handling digital information in the form of addressed messages. The system includes a master communication loop such as a transmission cable. A plurality of sub-loops as well as devices are connected to the master loop through suitable interface units and sub-loop control units. In each of the sub-loops a plurality of devices capable of transmitting and receiving digitally coded messages are connected to the sub-loops through interface units. Two special characters precede the message and permits a sub-loop control unit to take control of the loop to transmit messages and to obtain further messages from the devices in the associated sub-loop. When a unit is permitted to transmit, it produces and transmits a third special character which is received by the other interfaces or stations which are ready to transmit and informs the other interfaces that they may not transmit. After an interface transmits its message or messages, it produces the first and second special characters which is received by the next interface in the loop that is ready to transmit and in this manner, the sequence of transmission is passed around the loop under the control of the interfaces in the loop.
Inventors
- 👤 E Rocher
- 👤 S Schuster
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 15:33
CPC Classifications
H; H04; H04L; H04L12/00; H04L12/28; H04L12/46; H04L12/4637
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
230 words
A communication system comprising: a closed master transmission loop; a system control means that operates in discrete cycles, said master control means producing first and second framing characters at the beginnIng of each cycle; an interface means connected to said system control means and said master loop, said interface means including a switch connected in said loop master for transferring said first and second framing into said master loop for transmission around said master loop; a plurality of transmission sub-loops, each of said being connected to said master loop by a first interface connected to said master loop, each having a sub-loop control unit connected to said first interface, and a second interface connected to said sub-loop control unit and to a separate transmission subloop; each of said transmission sub-loops having a plurality of stations connected thereto, said stations being operable to transmit and receive digital messages; each of said sub-loop control units having a first storage means for storing messages to be transmitted from its associated subloop and a second storage means for storing messages to be received by its associated sub-loop; a first one of said sub-loop control units being responsive to said first and second framing characters to permit transmission of messages from its first storage means onto said master loop and concurrently producing a third framing character to prevent transmission from the other sub-loop control units.
Claim 2
Dependent Claim
230 words
A communication system comprising: a closed master transmission loop; a system control means that operates in discrete cycles, said master control means producing first and second framing characters at the beginnIng of each cycle; an interface means connected to said system control means and said master loop, said interface means including a switch connected in said loop master for transferring said first and second framing into said master loop for transmission around said master loop; a plurality of transmission sub-loops, each of said being connected to said master loop by a first interface connected to said master loop, each having a sub-loop control unit connected to said first interface, and a second interface connected to said sub-loop control unit and to a separate transmission subloop; each of said transmission sub-loops having a plurality of stations connected thereto, said stations being operable to transmit and receive digital messages; each of said sub-loop control units having a first storage means for storing messages to be transmitted from its associated subloop and a second storage means for storing messages to be received by its associated sub-loop; a first one of said sub-loop control units being responsive to said first and second framing characters to permit transmission of messages from its first storage means onto said master loop and concurrently producing a third framing character to prevent transmission from the other sub-loop control units.
Claim 3
Dependent Claim
77 words
A communication system according to claim 1 wherein said first one of said sub-loop control units produces said first and second framing characters and transmits said characters onto said transmission line after the transmission of the messages from said first sub-loop control unit to permit a second sub-loop control unit to transmit messages, said second sub-loop control unit also transmitting a third framing character onto said master loop to prevent the remaining sub-loop control units from transmitting.
Claim 4
Dependent Claim
107 words
A communication system according to claim 1 wherein each of said interfaces includes a receive register connected to said master loop on one side of the said switch therein and a transmit register connected to the master loop on the other side of said switch; a decoder connected to said receive register for detecting and producing signals upon the receptors of said first, second and third framing characters; a storage means connected to said transmit register for providing first, second and third framing characters to said transmit register; and control means connected to said decoder means and said storage means for controlling the sequence of operation thereof.
Claim 5
Dependent Claim
106 words
A communication system according to claim 1 wherein each of said sub-loop control unit includes means for receiving messages from said interface connected to said master loop; means for storing said messages from said master loop for one cycle of operation; and means for thereafter transmitting said messages from said master loop through said interface connected to said sub-loop; means for receiving messages from said interface connected to said sub-loop; means for storing said messages from said sub-loop for one cycle of operation; and means for thereafter transmitting said messages from said sub-loop through said interface connected to said master loop and onto said master loop.
References Cited (Backward Citations)
US3245043A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-05-07 | 1976-11-06 | 1977-05-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-05-07 | 1980-11-06 | 1981-05-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-05-07 | 1984-11-06 | 1985-05-08 | $7700.00 | Window Closed / Lapsed |