Patent US3752932A successfully refreshed from Google Patents.
US3752932A
Expired / Lapsed
US
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Loop communications system
Assignee: International Business Machines Corp
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Filing: 1971-12-14
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Granted: 1973-08-14
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Expires: 1991-12-14
Abstract
Abstract A communications system including a central station connected in a series loop with a plurality of remote stations and in which under control of said central station, the remote stations in the order of their physical position transmit data to the central station.
Inventors
- 👤 J Frisone
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 05:40
CPC Classifications
H; H04; H04L; H04L12/00; H04L12/28; H04L12/42; H04L12/423
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
182 words
A method of operating a serial loop binary coded data communications system having a central station and a plurality of remote stations connected in a serial loop comprising the steps of: at said central station transmitting a first unique coded signal to said remote stations which enables the subsequent transmission of data from each of the remote stations; and thereafter transmitting an uninterrupted string of signal bits designating one binary value; at said remote stations receiving the signal bits on the loop and examining said bits to detect the said first unique code signal enabling the subsequent transmission of data; following receipt of said unique coded signal initiating transmission following receipt of N contiguous one binary valued bits, said transmission having at least its first bit of said other binary value; completing transmission of the message only if the bit received at the remote station following receipt of said N contiguous bits is of said one binary value; and awaiting receipt of another first unique coded signal following receipt of N+1 consecutive one binary valued bits before attempting to transmit another message.
Claim 2
Independent Claim
182 words
A method of operating a serial loop binary coded data communications system having a central station and a plurality of remote stations connected in a serial loop comprising the steps of: at said central station transmitting a first unique coded signal to said remote stations which enables the subsequent transmission of data from each of the remote stations; and thereafter transmitting an uninterrupted string of signal bits designating one binary value; at said remote stations receiving the signal bits on the loop and examining said bits to detect the said first unique code signal enabling the subsequent transmission of data; following receipt of said unique coded signal initiating transmission following receipt of N contiguous one binary valued bits, said transmission having at least its first bit of said other binary value; completing transmission of the message only if the bit received at the remote station following receipt of said N contiguous bits is of said one binary value; and awaiting receipt of another first unique coded signal following receipt of N+1 consecutive one binary valued bits before attempting to transmit another message.
Claim 3
Dependent Claim
45 words
The method set forth in claim 1 in which at each of said remote stations a count is maintained of the receipt of said one valued bits and reset upon the receipt of a said other value bit provided the count has not reached N+1.
Claim 4
Dependent Claim
239 words
A data transmission system comprising: a central station; a plurality of remote stations each including a data source; means for interconnecting said central station and said remote station in a serial loop; said central station including means for generating and transmitting to said remote stations a first unique coded control signal which authorizes transmission of data from said remote stations, and means for generating and transmitting to said remote stations an uninterrupted series of uniform signal bits of one of at least two possible states immediately following the transmission of said first unique coded control signal; said remote stations each including, means for receiving and inserting data from the said loop, means for examining the data on the loop for detecting the presence of said first unique control signal, means operative following receipt of said first unique control signal for detecting the presence of N consecutive uniform signal bits of said one state, means for initiating the transmission of data from said data source if said data source has data to transmit, following detection of N consecutive signal bits of said one state, said data including a leading bit differing in state from said bits of said one sTate, and means responsive to the receipt of N+1 consecutive signal bits of said one state for permitting completion of data transmission and for inhibiting the start of transmission of another message until a subsequent first unique control signal is received.
Claim 5
Dependent Claim
239 words
A data transmission system comprising: a central station; a plurality of remote stations each including a data source; means for interconnecting said central station and said remote station in a serial loop; said central station including means for generating and transmitting to said remote stations a first unique coded control signal which authorizes transmission of data from said remote stations, and means for generating and transmitting to said remote stations an uninterrupted series of uniform signal bits of one of at least two possible states immediately following the transmission of said first unique coded control signal; said remote stations each including, means for receiving and inserting data from the said loop, means for examining the data on the loop for detecting the presence of said first unique control signal, means operative following receipt of said first unique control signal for detecting the presence of N consecutive uniform signal bits of said one state, means for initiating the transmission of data from said data source if said data source has data to transmit, following detection of N consecutive signal bits of said one state, said data including a leading bit differing in state from said bits of said one sTate, and means responsive to the receipt of N+1 consecutive signal bits of said one state for permitting completion of data transmission and for inhibiting the start of transmission of another message until a subsequent first unique control signal is received.
Claim 6
Dependent Claim
72 words
A data transmission system as set forth in claim 3 in which the means at the remote stations for detecting N consecutive uniform signal bits of said one designation includes a counter means which increments each time a bit of said one designation is received and resets to a predetermined state when a bit other than said one designation is received provided N+1 bits of said one designation have not been received.
Claim 7
Dependent Claim
63 words
A data transmission system as set forth in claim 4 in which the means for receiving and inserting data from the loop includes a two-position switch arranged to provide an uninterrupted flow of data on the loop in one position and in its alternate position to interrupt the loop and permit the introduction of data originating at the data source on the loop.
Claim 8
Dependent Claim
52 words
A data transmission system as set forth in claim 4 in which the means for receiving and inserting data from the loop includes a shift register having at least one bit of storage arranged in the loop and switching means for selectively gating data bits out of and into the shift register.
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) | 1976-08-13 | 1977-02-12 | 1977-08-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-08-13 | 1981-02-12 | 1981-08-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-08-13 | 1985-02-12 | 1985-08-14 | $7700.00 | Window Closed / Lapsed |