US3632881A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Data communications method and system
Assignee: International Business Machines Corp
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Filing: 1970-03-16
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Granted: 1972-01-04
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Expires: 1990-03-16
Abstract
Abstract A method of bidirectionally communicating data between a central control unit and a plurality of serially looped local control units in which a number of time-separated contiguous time slots are provided, the number of slots being substantially greater than one and substantially less than the maximum number of local controllers. The number of contiguous time slots are preceded by a header which includes synchronizing control and addressing data which permits local controllers to initiate transmission or reception of data which will continue via the specific slot assigned by the control data for the duration of the then initiated data exchange.
Inventors
- 👤 William I Graham
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 13:49
CPC Classifications
H; H04; H04L; H04L12/00; H04L12/28; H04L12/42; H04L12/423
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
173 words
A method for bidirectionally communicating coded data between a central station and a plurality of serially looped local stations comprising the steps of: providing a fixed number of time-separated contiguous time slots in which the number of slots provided is much greater than one and substantially less than the maximum number of local stations; providing a header section for each fixed number of timeseparated contiguous time slots which includes; a first group of uniquely coded bits for identifying the beginning of the fixed number of time-separated contiguous time slots and for permitting the local stations to synchronize their operation therewith, a second group of control bits including a first part for designating one of several communications functions which are initiated in at least one but substantially less than all of the fixed number of time slots and a second part for identifying the time slot within which the initiated function will take place, and a third group of address bits for identifying at least one local station which is to initiate the function.
Claim 2
Independent Claim
173 words
A method for bidirectionally communicating coded data between a central station and a plurality of serially looped local stations comprising the steps of: providing a fixed number of time-separated contiguous time slots in which the number of slots provided is much greater than one and substantially less than the maximum number of local stations; providing a header section for each fixed number of timeseparated contiguous time slots which includes; a first group of uniquely coded bits for identifying the beginning of the fixed number of time-separated contiguous time slots and for permitting the local stations to synchronize their operation therewith, a second group of control bits including a first part for designating one of several communications functions which are initiated in at least one but substantially less than all of the fixed number of time slots and a second part for identifying the time slot within which the initiated function will take place, and a third group of address bits for identifying at least one local station which is to initiate the function.
Claim 3
Independent Claim
237 words
A method for transmitting data from a plurality of remotely located stations to a central station in which the remote stations are connected in a serial loop with the central station comprising the stEps of: providing a fixed number of time-separated contiguous time slots within which data is transmitted on the station interconnecting line and in which the number of slots provided is substantially greater than one and substantially less than the maximum number of remote stations; providing a header section for each fixed number of time-separated contiguous time slots which includes; a first group of uniquely coded bits for identifying the beginning of the fixed number of time-separated contiguous time slots and for permitting the remote station to synchronize operation therewith, a section group of control bits including a first part for indicating the availability of at least one time slot and a second part for identifying the available time slot, a third group of bits for identifying at least one local station which requires service, for each remote station requiring transmission service changing the first part of the second group of control bits to a nonavailable condition, registering the second part of the second group of control bits to provide access to the available slot, and inserting the address of the remote station requiring service in the third group of bits to indicate to the central station the remote station communicating in the available channel.
Claim 4
Independent Claim
237 words
A method for transmitting data from a plurality of remotely located stations to a central station in which the remote stations are connected in a serial loop with the central station comprising the stEps of: providing a fixed number of time-separated contiguous time slots within which data is transmitted on the station interconnecting line and in which the number of slots provided is substantially greater than one and substantially less than the maximum number of remote stations; providing a header section for each fixed number of time-separated contiguous time slots which includes; a first group of uniquely coded bits for identifying the beginning of the fixed number of time-separated contiguous time slots and for permitting the remote station to synchronize operation therewith, a section group of control bits including a first part for indicating the availability of at least one time slot and a second part for identifying the available time slot, a third group of bits for identifying at least one local station which requires service, for each remote station requiring transmission service changing the first part of the second group of control bits to a nonavailable condition, registering the second part of the second group of control bits to provide access to the available slot, and inserting the address of the remote station requiring service in the third group of bits to indicate to the central station the remote station communicating in the available channel.
Claim 5
Independent Claim
225 words
A method for transmitting data from a central station to a plurality of remote stations in which the remote stations are connected in a serial loop with the central station comprising the steps of: providing a fixed number of time-separated contiguous time slots within which data is transmitted by the central on the station interconnecting lines to the remote station and in which the number of slots provided is substantially greater than one and substantially less than the maximum number of remote stations; providing a header section for each fixed number of time-separated contiguous slots which includes; a first group of uniquely coded bits for identifying the beginning of the fixed number of time-separated contiguous time slots and for permitting the remote stations to synchronize operation therewith, a second group of control bits including a first part for indicating that at least one slot but substantially less than the total number of slots is being assigned to a remote station to initiate one of several communications functions and a second part for identifying the assigned slot, a third group of bits for identifying the remote station which is to accept data in the slot identified, and registering the slot address at the addressed remote station to permit access to the assigned slot during the subsequent slot period until transmission is terminated by the central station.
Claim 6
Independent Claim
225 words
A method for transmitting data from a central station to a plurality of remote stations in which the remote stations are connected in a serial loop with the central station comprising the steps of: providing a fixed number of time-separated contiguous time slots within which data is transmitted by the central on the station interconnecting lines to the remote station and in which the number of slots provided is substantially greater than one and substantially less than the maximum number of remote stations; providing a header section for each fixed number of time-separated contiguous slots which includes; a first group of uniquely coded bits for identifying the beginning of the fixed number of time-separated contiguous time slots and for permitting the remote stations to synchronize operation therewith, a second group of control bits including a first part for indicating that at least one slot but substantially less than the total number of slots is being assigned to a remote station to initiate one of several communications functions and a second part for identifying the assigned slot, a third group of bits for identifying the remote station which is to accept data in the slot identified, and registering the slot address at the addressed remote station to permit access to the assigned slot during the subsequent slot period until transmission is terminated by the central station.
Claim 7
Independent Claim
361 words
A method for bidirectionally transmitting coded data between a central station and a plurality of remote stations in which the remote stations are connected in a serial loop with the central station comprising the steps of: providing a fixed number of time-separated contiguous time slots within which coded data is transmitted on the station interconnecting line between the remote stations and the central station and in which the number of slots provided is substantially greater than one and substantially less than the maximum number of remote stations; providing a header section for each fixed number of time-separated contiguous time slots which includes; a first group of uniquely coded bits for identifying the beginning of the fixed number of time-separated contiguous time slots and for permitting the remote stations to synchronize operation therewith, a second group of control bits including a first part for designating at least one of several communications functions which can be initiated in at least one of the fixed number of time slots and a second part for identifying at least one time slot within which the designated communications function is initiated, a third group of bits for identifying at least one local station which is tO initiate a communications function in the identified time slot, at each remote station examining the bit stream to detect the first header group for maintaining slot synchronization with the bit stream; and at each noncommunicating remote station examining the first part of the second group to determine the function initiated in the associated time slots, registering the slot identification, examining the third group of bits if communications from the central to the remote are being initiated and accepting data from the registered time slot if the remote address in the third group corresponds to the remote station address until instructed by data accepted to cease, and if communications from the remote to the central are required, changing the first part of the second group to a neutral state, inserting the remote station address in the third group of bits to identify the transmitting station, and communicating data to the central in the registered time slot until all data has been communicated.
Claim 8
Independent Claim
361 words
A method for bidirectionally transmitting coded data between a central station and a plurality of remote stations in which the remote stations are connected in a serial loop with the central station comprising the steps of: providing a fixed number of time-separated contiguous time slots within which coded data is transmitted on the station interconnecting line between the remote stations and the central station and in which the number of slots provided is substantially greater than one and substantially less than the maximum number of remote stations; providing a header section for each fixed number of time-separated contiguous time slots which includes; a first group of uniquely coded bits for identifying the beginning of the fixed number of time-separated contiguous time slots and for permitting the remote stations to synchronize operation therewith, a second group of control bits including a first part for designating at least one of several communications functions which can be initiated in at least one of the fixed number of time slots and a second part for identifying at least one time slot within which the designated communications function is initiated, a third group of bits for identifying at least one local station which is tO initiate a communications function in the identified time slot, at each remote station examining the bit stream to detect the first header group for maintaining slot synchronization with the bit stream; and at each noncommunicating remote station examining the first part of the second group to determine the function initiated in the associated time slots, registering the slot identification, examining the third group of bits if communications from the central to the remote are being initiated and accepting data from the registered time slot if the remote address in the third group corresponds to the remote station address until instructed by data accepted to cease, and if communications from the remote to the central are required, changing the first part of the second group to a neutral state, inserting the remote station address in the third group of bits to identify the transmitting station, and communicating data to the central in the registered time slot until all data has been communicated.
Claim 9
Dependent Claim
363 words
A communications system comprising: a central station; a plurality of remote stations; transmission means interconnecting said central station and said plurality or remote stations in a serial loop for bidirectional data communications in one direction; means at said central station for repetitively transmitting onto said loop, a header section followed by a fixed number of time-separated contiguous time slots, said header section including; a first group of uniquely coded bits for identifying the beginning of the fixed number of time-separated contiguous time slots and for enabling slot synchronization at said remote stations, a second group of control bits for designating one of several functions which are initiated in at least one of the fixed number of time slots, and a third group of address bits for identifying at least one remote station which is to initiate the designated first function; first means at each of said remote stations for monitoring the bit stream on the transmission means and for detecting the said first group of bits; counter means at each station responsive to the first means for establishing a slot count for identifying the slots as they are received; second means at each station for examining the second group of bits to decode the function initiated; third means at each station for registering part of the second group of bits in the header when the remote station is not transmitting or receiving data; first selectively operable means at each station for selectively altering part of the second group of bits and for inserting a unique station address in the third group of address bits when communications between the remote station and the central station are needed; fourth means responsive to the second means when the function indicated by the second group of bits indicates reception of data from the central station for examining the third group of address bits for decoding a unique remote station address code and for enabling data reception at the remote station; and fifth means responsive to the counter means and the third means for permitting the station to receive or send data via the transmission loop when the counter means and the third means have a predetermined relationship.
Claim 10
Dependent Claim
363 words
A communications system comprising: a central station; a plurality of remote stations; transmission means interconnecting said central station and said plurality or remote stations in a serial loop for bidirectional data communications in one direction; means at said central station for repetitively transmitting onto said loop, a header section followed by a fixed number of time-separated contiguous time slots, said header section including; a first group of uniquely coded bits for identifying the beginning of the fixed number of time-separated contiguous time slots and for enabling slot synchronization at said remote stations, a second group of control bits for designating one of several functions which are initiated in at least one of the fixed number of time slots, and a third group of address bits for identifying at least one remote station which is to initiate the designated first function; first means at each of said remote stations for monitoring the bit stream on the transmission means and for detecting the said first group of bits; counter means at each station responsive to the first means for establishing a slot count for identifying the slots as they are received; second means at each station for examining the second group of bits to decode the function initiated; third means at each station for registering part of the second group of bits in the header when the remote station is not transmitting or receiving data; first selectively operable means at each station for selectively altering part of the second group of bits and for inserting a unique station address in the third group of address bits when communications between the remote station and the central station are needed; fourth means responsive to the second means when the function indicated by the second group of bits indicates reception of data from the central station for examining the third group of address bits for decoding a unique remote station address code and for enabling data reception at the remote station; and fifth means responsive to the counter means and the third means for permitting the station to receive or send data via the transmission loop when the counter means and the third means have a predetermined relationship.
Claim 11
Dependent Claim
59 words
A communications system as set forth in claim 5 in which said second group of control bits in the header section includes a first part for designating at least one of several communications functions which is to be initiated and a second part for indicating which of the time slots is to be used for the initiated communications function.
Claim 12
Dependent Claim
321 words
A communications system comprising: a central station; a plurality of remote stations; transmission means interconnecting said central station and said plurality of remote stations in a serial loop for transmitting data from said central station to said remote stations; means at said central station for repetitively tRansmitting onto said transmission means a header section followed by a fixed number of time-separated contiguous time slots containing data for selected remote stations; said header section including; a first group of uniquely coded bits for identifying the beginning of the fixed number of time-separated contiguous time slots for enabling slot synchronization at said remote stations, a second group of control bits indicating the initiation of transmission of data from the central to a remote station in at least one identified time slot, and a third group of address bits for identifying at least one remote station which is to receive the data in the identified time slot, first means at each said remote station for monitoring the bit stream on the transmission means and for detecting the said first group of bits; counter means at each remote station responsive to the first means for establishing a slot count for identifying the slots as they are received; second means at each remote station for examining the second group of control bits to detect the initiation of a data transfer from the central to a remote station; third means at each remote station for registering the slot identification contained in the second group of control bits; fourth means for examining the third group of address bits for decoding a unique remote station address code and for enabling data reception at the remote station; and fifth means responsive to the counter means and the third means for accepting data on the transmission loop when the counter means and the third means bear a predetermined relationship to each other and reception is enabled by the said fourth means.
Claim 13
Dependent Claim
321 words
A communications system comprising: a central station; a plurality of remote stations; transmission means interconnecting said central station and said plurality of remote stations in a serial loop for transmitting data from said central station to said remote stations; means at said central station for repetitively tRansmitting onto said transmission means a header section followed by a fixed number of time-separated contiguous time slots containing data for selected remote stations; said header section including; a first group of uniquely coded bits for identifying the beginning of the fixed number of time-separated contiguous time slots for enabling slot synchronization at said remote stations, a second group of control bits indicating the initiation of transmission of data from the central to a remote station in at least one identified time slot, and a third group of address bits for identifying at least one remote station which is to receive the data in the identified time slot, first means at each said remote station for monitoring the bit stream on the transmission means and for detecting the said first group of bits; counter means at each remote station responsive to the first means for establishing a slot count for identifying the slots as they are received; second means at each remote station for examining the second group of control bits to detect the initiation of a data transfer from the central to a remote station; third means at each remote station for registering the slot identification contained in the second group of control bits; fourth means for examining the third group of address bits for decoding a unique remote station address code and for enabling data reception at the remote station; and fifth means responsive to the counter means and the third means for accepting data on the transmission loop when the counter means and the third means bear a predetermined relationship to each other and reception is enabled by the said fourth means.
Claim 14
Dependent Claim
379 words
A communications system comprising: a central station; a plurality of remote stations; transmission means interconnecting said central station and said plurality of remote stations in a serial loop for transmitting data from said remote stations to said central station; means at said central station for repetitively transmitting onto said transmission means a header section followed by a fixed number of time-separated contiguous time slots for containing data to be transmitted from the remote stations to the central station; said header section including; a group of uniquely coded bits for identifying the beginning of the fixed number of time-separated contiguous time slots and for enabling slot synchronization at said remote stations, a second group of control bits indicating the initiation of transmission of data from a remote station to the central station in at least one identified time slot, and a third group of address bits for identifying to the central a remote station initiating data transfer to the central via the slot identified in the second group of control bits, first means at each of said remote stations for monitoring the bit stream on the transmission means and for detecting the said first group of bits; counter means at each remote station responsive to the first means for establishing a slot count for identifying the slots as they are received; second means at each remote station for examining the second group of control bits to detect the initiation of a data transfer from the remote stations to the central station; third means at each remote station responsive to the second means for altering the second group of control bits when the station has data to transmit to the central so that subsequent remote stations will be inhibited from transmitting in the identified slot and for inserting a unique station address in the third group of address bits; fourth means at each remote station for registering the slot identification contained in the second group of control bits if the remote station has data to transmit to the central; and fifth means responsive to the counter means and the fourth means for inserting data to be transmitted from the remote station to the central station into the transmIssion means when the counter means and the fourth means have a predetermined relationship.
Claim 15
Dependent Claim
379 words
A communications system comprising: a central station; a plurality of remote stations; transmission means interconnecting said central station and said plurality of remote stations in a serial loop for transmitting data from said remote stations to said central station; means at said central station for repetitively transmitting onto said transmission means a header section followed by a fixed number of time-separated contiguous time slots for containing data to be transmitted from the remote stations to the central station; said header section including; a group of uniquely coded bits for identifying the beginning of the fixed number of time-separated contiguous time slots and for enabling slot synchronization at said remote stations, a second group of control bits indicating the initiation of transmission of data from a remote station to the central station in at least one identified time slot, and a third group of address bits for identifying to the central a remote station initiating data transfer to the central via the slot identified in the second group of control bits, first means at each of said remote stations for monitoring the bit stream on the transmission means and for detecting the said first group of bits; counter means at each remote station responsive to the first means for establishing a slot count for identifying the slots as they are received; second means at each remote station for examining the second group of control bits to detect the initiation of a data transfer from the remote stations to the central station; third means at each remote station responsive to the second means for altering the second group of control bits when the station has data to transmit to the central so that subsequent remote stations will be inhibited from transmitting in the identified slot and for inserting a unique station address in the third group of address bits; fourth means at each remote station for registering the slot identification contained in the second group of control bits if the remote station has data to transmit to the central; and fifth means responsive to the counter means and the fourth means for inserting data to be transmitted from the remote station to the central station into the transmIssion means when the counter means and the fourth means have a predetermined relationship.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-01-03 | 1975-07-05 | 1976-01-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-01-03 | 1979-07-05 | 1980-01-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-01-03 | 1983-07-05 | 1984-01-04 | $7700.00 | Window Closed / Lapsed |