US3821706A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Computer system
Assignee: Allen Bradley Co LLC
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Filing: 1973-03-29
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Granted: 1974-06-28
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Expires: 1993-03-29
Abstract
Abstract A plurality of remote terminals are connected to a central computer through a full duplex communication channel. Each terminal has a register which stores the unique address for that terminal, a counter and a comparator circuit for determining identity between the state of the counter and the address. The computer transmits messages to all of the remote terminals consisting of digital word groups preceded by a particular terminal address. These messages are received by all of the terminals and only processed by the terminal so addressed. All of the terminals advance their counters in response to each word transmitted by the computer, whether that word is addressed to them or not. In the absence of a message to be sent to the terminals, the computer transmits an idle word which advances all of the counters. Upon the occurrence of identity between its counter and its address, a terminal will transmit any available message to the computer on the return channel. Periodically, a word is sent out by the computer resynchronizing all of the counters. In one alternate embodiment the central station communicates with a plurality of satellite stations, each of which services a plurality of terminals and interrogates them in sequence, one each time that satellite''s counter coincides with its address. In another alternate embodiment all of the terminals connected to a particular satellite are sequentially interrogated as the counter in the satellite is advanced by sequential words generated by the computer, and then the computer transmits the address of another satellite causing its terminals to be sequentially interrogated.
Inventors
- 👤 M Bennett
- 👤 T Vlach
- 👤 A Edwin
- 👤 G Venturi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 14:04
CPC Classifications
G; G06; G06F; G06F13/00; G06F13/14; G06F13/36; G06F13/368; G06F13/372
Claims Analysis
Total Claims: 25
Claim 1
Independent Claim
152 words
A digital communication system including a master station and a plurality of remote terminals all connected by a communication channel including; means for storing a unique address at each of the terminals; counters associated with the master station and each of the remote terminals; means at each remote terminal for detecting coincidence between the status of its counter and its address storage means; means at the master station for sending digital words to all of the remote terminals, said words including an address of one of the terminals followed by data to be received by that terminal; means for advancing the master counter and each of the terminal counters each time a digital word is sent from the master to any of the terminals; and means at each terminal allowing the terminal to send a message to the master upon the occurrence of coincidence between that terminal''s counter and its address memory.
Claim 2
Dependent Claim
152 words
A digital communication system including a master station and a plurality of remote terminals all connected by a communication channel including; means for storing a unique address at each of the terminals; counters associated with the master station and each of the remote terminals; means at each remote terminal for detecting coincidence between the status of its counter and its address storage means; means at the master station for sending digital words to all of the remote terminals, said words including an address of one of the terminals followed by data to be received by that terminal; means for advancing the master counter and each of the terminal counters each time a digital word is sent from the master to any of the terminals; and means at each terminal allowing the terminal to send a message to the master upon the occurrence of coincidence between that terminal''s counter and its address memory.
Claim 3
Dependent Claim
21 words
The system of claim 1 wherein means are provided for periodically resetting the master counter and all of the terminal counters.
Claim 4
Dependent Claim
33 words
The system of claim 2 wherein the means for resetting the master counter and the terminal counters comprises a unique synchronizing word generated by the master and transmitted to all of the terminals.
Claim 5
Dependent Claim
36 words
The system of claim 1 wherein the system is full duplex and the measages transmitted from a terminal to the master are sent simultaneously with the transmission of digital words from the master to the terminals.
Claim 6
Dependent Claim
38 words
The system of claim 1 wherein in the absence of a message digital word to be transmitted from the master to the terminals the master transmits an idle word which advances the counters at all of the terminals.
Claim 7
Dependent Claim
35 words
The system of claim 5 wherein an idle word consists of a plurality of bits, the first of the bits being of one state and the balance of the bits being of the opposite state.
Claim 8
Dependent Claim
37 words
The system of claim 6 wherein the master station periodically transmits a synchronizing word to all of the terminals and wherein at least two idle words are sequentially transmitted by the master station before each synchronizing word.
Claim 9
Dependent Claim
47 words
The system of claim 1 wherein each terminal services a plurality of secondary terminals and following the occurence of identity between the counter associated with a terminal and the address of that terminal, that terminal transmits a message from one of said secondary terminals to said master.
Claim 10
Dependent Claim
98 words
In a computer system having a central station, a plurality of satellites, and a plurality of terminals connected to said central station through said satellites, a first counter associated with said central station; first counters associated with each of said satellites; means for advancing the first counter associated with the central station and the first counters associated with the satellites upon each transmission of a digital word from the central station to the terminals, and means associated with each satellite for directing communications from its associated terminals to the central station under control of that satellite''s first counter.
Claim 11
Dependent Claim
98 words
In a computer system having a central station, a plurality of satellites, and a plurality of terminals connected to said central station through said satellites, a first counter associated with said central station; first counters associated with each of said satellites; means for advancing the first counter associated with the central station and the first counters associated with the satellites upon each transmission of a digital word from the central station to the terminals, and means associated with each satellite for directing communications from its associated terminals to the central station under control of that satellite''s first counter.
Claim 12
Dependent Claim
56 words
The computer system of claim 9 wherein the central station and each satellite contain a second counter and the transmission of a communication from a terminal associated with a satellite to the central station is performed under control of the second counter associated with that satellite as well as the first counter associated with that satellite.
Claim 13
Dependent Claim
45 words
The computer system of claim 9 wherein each satellite has a unique address and wherein means are provided for allowing transmissions from a remote terminal associated with a satellite to the central station only following the central station transmitting the address of that particular satellite.
Claim 14
Dependent Claim
57 words
The computer system of claim 11 wherein a satellite operates to transmit messages from various of its terminals to the central station during the time its counter undergoes a number of changes of state equal to the number of terminals associated with that satellite following the transmission of the address of that satellite by the central station.
Claim 15
Dependent Claim
34 words
The computer system of claim 9 including means, associated with the central station, for transmitting messages to all of the satellites to effect the resetting of the first counters in all of the satellites.
Claim 16
Dependent Claim
142 words
A digital communication system including a central station and a plurality of terminals located remotely from one another and from the central station and all connected by a communication channel comprising; means for transmitting a plurality of digital words from the central station to the remote terminals over the communication channel, the words consisting of addresses of the terminals and message words for the terminals; means for sToring a unique address at each of the terminals; counters associated with each terminal, the counters being advanced upon the reception of each digital address word and message word from the central station; message storage means associated with each terminal; and means for transmitting a message from the message storage means associated with a particular terminal to said central station upon the occurrence of identity between the address of that terminal and its associated counter.
Claim 17
Dependent Claim
142 words
A digital communication system including a central station and a plurality of terminals located remotely from one another and from the central station and all connected by a communication channel comprising; means for transmitting a plurality of digital words from the central station to the remote terminals over the communication channel, the words consisting of addresses of the terminals and message words for the terminals; means for sToring a unique address at each of the terminals; counters associated with each terminal, the counters being advanced upon the reception of each digital address word and message word from the central station; message storage means associated with each terminal; and means for transmitting a message from the message storage means associated with a particular terminal to said central station upon the occurrence of identity between the address of that terminal and its associated counter.
Claim 18
Dependent Claim
34 words
The digital communication system of claim 14 wherein the terminal transmits a single digital message word to the central station each time identity is established between its associated counter and its unique address word.
Claim 19
Dependent Claim
42 words
The digital communication system of claim 15 including data input means connected to said message storage means, said data input means having a data rate which differs from the data rate at which said terminal may transmit messages to said central station.
Claim 20
Dependent Claim
33 words
The digital communication system of claim 14 including a counter at the master station which is advanced upon the transmission of a digital word from the master station to any of the terminals.
Claim 21
Dependent Claim
21 words
The digital communication system of claim 17 including means for periodically resetting the master counter and all of the terminal counters.
Claim 22
Dependent Claim
54 words
The digital communication system of claim 14 wherein the communication channel is bidirectional and in a transmission from a terminal to the central station following the occurrence of coincidence between that central station''s counter and its unique address may occur simultaneously with the transmission of digital words from the central station to the terminals.
Claim 23
Dependent Claim
81 words
A computer system having a central station; a plurality of satellites; a plurality of terminals connected to said central station through said satellites; means for advancing the counter associated with the central station and the counters associated with the satellites upon each transmission of a digital word from the central station to the terminals; and means associated with each satellite for directing communications from one of its associated terminals to the central station upon that terminal''s counter attaining a predetermined state.
Claim 24
Dependent Claim
81 words
A computer system having a central station; a plurality of satellites; a plurality of terminals connected to said central station through said satellites; means for advancing the counter associated with the central station and the counters associated with the satellites upon each transmission of a digital word from the central station to the terminals; and means associated with each satellite for directing communications from one of its associated terminals to the central station upon that terminal''s counter attaining a predetermined state.
Claim 25
Dependent Claim
42 words
The computer system of claim 20 wherein each satellite has a unique address and each satellite directs the communication from one of its associated terminals to the central station upon occurrence of coincidence between that satellite''s counter and the satellite''s unique address.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-06-27 | 1977-12-27 | 1978-06-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-06-27 | 1981-12-27 | 1982-06-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-06-27 | 1985-12-27 | 1986-06-28 | $7700.00 | Window Closed / Lapsed |