US3891804A
Expired / Lapsed
US
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Asynchronous data transmission arrangement
Assignee: AT&T Inc
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Filing: 1973-09-12
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Granted: 1975-06-24
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Expires: 1993-09-12
Abstract
Abstract A data transmission arrangement is disclosed wherein messages consisting of a synchronization code field, a destination terminal code field, a source terminal code field with sufficient bit capacity for both a source terminal code and a synchronization code, and a data field are transmitted between a plurality of transmission node terminals which are serially connected in a closed, asynchronous data transmission loop. Each node terminal contains a control circuit and a plurality of shift registers which the control circuit selectively connects in series with the data transmission loop to receive or to transmit the various fields of a message. In receiving a message only those shift registers of the receiving node terminal which are necessary to receive the synchronization code and the destination terminal code for the message are initially connected in series with the transmission path. If the message is not intended for the particular node terminal, no additional shift registers are employed and the message passes through the node terminal with only the message delay inherent in the use of the initially connected shift registers. If the message is intended for the node terminal, additional registers are employed to receive the remaining message fields. A message may be transmitted from a node terminal whenever the terminal determines that no message is currently being received. As a message is transmitted the control circuit removes shift registers from series connection in the data path as soon as possible to minimize possible transmission delay to messages received by the node terminal during the remainder of the message transmission. If during the transmission of a message from a node terminal, a message is received by that node terminal, it is shifted into whatever shift registers are currently connected in series with the data path and, thereafter, treated as any other received message.
Inventors
- 👤 Victor Hachenburg
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 06:48
CPC Classifications
H; H04; H04L; H04L12/00; H04L12/28; H04L12/42; H04L12/427; H04L12/433
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
414 words
In a transmission arrangement for transmitting messages between a plurality of transmission node terminals, wherein each message comprises a first field of a first number of bits, a second field of a second number of bits, and a third field of a third number of bits equal to the sum of said first and second number of bits, a transmission node terminal, having an input port and an output port, comprising: a clock signal generator; a first shift register, connected to said clock signal generator, comprising a serial input terminal, a serial output terminal, and a number of register stages eQual to said first number of bits; means for connecting said input port to said serial input terminal of said first shift register; a second shift register, connected to said clock signal generator, comprising a serial input terminal, a serial output terminal, and a number of register stages equal to said third number of bits; means connected to said serial output terminal of said first shift register for gating signals to said input terminal of said second shift register; means connected to said serial output terminal of said first shift register for gating signals to said output port; means connected to said serial output terminal of said second shift register for gating signal to said output port; a third shift register, connected to said clock signal generator, comprising a serial input terminal, a serial output terminal, and a number of register stages equal to said third number of bits; means connected to said serial output terminal of said first shift register for gating signals to said input terminal of said third shift register; means connected to said serial output terminal of said third shift register for gating signals of said output port; a fourth shift register connected to said clock signal generator comprising a serial input terminal, a serial output terminal, and at least one register stage; means connected to said serial output terminal of said first shift register for gating signals to said input terminal of said fourth shift register; means connected to said serial output terminal of said fourth shift register for gating signals to the input terminal of said second shift register; means connected to said serial output terminal of said fourth shift register for gating signals to said input terminal of said third shift register; and means connected to said serial output terminal of said second shift register for gating signals to said input terminal of said third shift register.
Claim 2
Dependent Claim
414 words
In a transmission arrangement for transmitting messages between a plurality of transmission node terminals, wherein each message comprises a first field of a first number of bits, a second field of a second number of bits, and a third field of a third number of bits equal to the sum of said first and second number of bits, a transmission node terminal, having an input port and an output port, comprising: a clock signal generator; a first shift register, connected to said clock signal generator, comprising a serial input terminal, a serial output terminal, and a number of register stages eQual to said first number of bits; means for connecting said input port to said serial input terminal of said first shift register; a second shift register, connected to said clock signal generator, comprising a serial input terminal, a serial output terminal, and a number of register stages equal to said third number of bits; means connected to said serial output terminal of said first shift register for gating signals to said input terminal of said second shift register; means connected to said serial output terminal of said first shift register for gating signals to said output port; means connected to said serial output terminal of said second shift register for gating signal to said output port; a third shift register, connected to said clock signal generator, comprising a serial input terminal, a serial output terminal, and a number of register stages equal to said third number of bits; means connected to said serial output terminal of said first shift register for gating signals to said input terminal of said third shift register; means connected to said serial output terminal of said third shift register for gating signals of said output port; a fourth shift register connected to said clock signal generator comprising a serial input terminal, a serial output terminal, and at least one register stage; means connected to said serial output terminal of said first shift register for gating signals to said input terminal of said fourth shift register; means connected to said serial output terminal of said fourth shift register for gating signals to the input terminal of said second shift register; means connected to said serial output terminal of said fourth shift register for gating signals to said input terminal of said third shift register; and means connected to said serial output terminal of said second shift register for gating signals to said input terminal of said third shift register.
Claim 3
Dependent Claim
282 words
In a transmission arrangement for serially communicating digital messages each comprising a destination address portion, a source address portion, and a data portion between a plurality of transmission terminals serially connected in a transmission loop, a transmission terminal having a unique identification code comprising: an input port; an output port; a first serial storage means comprising a serial input terminal and a serial output terminal; means for connecting said serial input terminal of said first storage means to said input port; a second serial storage means, having less storage capacity than required to store an entire one of said digital messages, comprising a serial input terminal and a serial output terminal; first gating means for gating signals from the output terminal of said first serial storage means to the input terminal of said second storage means; detector means responsive to signals stored in said second serial storage means for generating local destination code control signals indicating that the destination address of a received message is the unique identification code of the respective transmission terminal; second gating means connected to said serial output terminal of said second storage means for gating signals to said output port; serial information storage means having sufficient capacity to store the source address portion and data portion of a digital message; means responsive to said local destination code control signals for inhibiting said first gating means from gating signals to said second serial storage means and for inhibiting said second gating means from gating signals to said output port; third gating means responsive to said local destination code control signals for gating signals from the output terminal of said first storage means to said serial information storage means.
Claim 4
Dependent Claim
282 words
In a transmission arrangement for serially communicating digital messages each comprising a destination address portion, a source address portion, and a data portion between a plurality of transmission terminals serially connected in a transmission loop, a transmission terminal having a unique identification code comprising: an input port; an output port; a first serial storage means comprising a serial input terminal and a serial output terminal; means for connecting said serial input terminal of said first storage means to said input port; a second serial storage means, having less storage capacity than required to store an entire one of said digital messages, comprising a serial input terminal and a serial output terminal; first gating means for gating signals from the output terminal of said first serial storage means to the input terminal of said second storage means; detector means responsive to signals stored in said second serial storage means for generating local destination code control signals indicating that the destination address of a received message is the unique identification code of the respective transmission terminal; second gating means connected to said serial output terminal of said second storage means for gating signals to said output port; serial information storage means having sufficient capacity to store the source address portion and data portion of a digital message; means responsive to said local destination code control signals for inhibiting said first gating means from gating signals to said second serial storage means and for inhibiting said second gating means from gating signals to said output port; third gating means responsive to said local destination code control signals for gating signals from the output terminal of said first storage means to said serial information storage means.
Claim 5
Dependent Claim
90 words
A transmission terminal in accordance with claim 2 wherein said serial information storage means further comprises a third serial Storage means and a fourth serial storage means; and wherein said third gating means further comprises means for gating the source address portion of a received data message from the output terminal of said first serial storage means to said third storage means and means for gating the data portion of said received digital message from the output terminal of said first serial storage means to said fourth serial storage means.
Claim 6
Dependent Claim
99 words
The transmission terminal in accordance with claim 3 further comprising: counting means connected to said input port for counting the digits of a received digital message and for generating count signals indicating the number of digits received; means responsive to said count signals for generating completed message signals indicating that a completed one of said digital messages has been received by said transmission terminal; means responsive to said completed message signals for gating signals from the output terminal of said first serial storage means to said output port; and means for inhibiting the generation of said completed message signals.
Claim 7
Dependent Claim
29 words
The terminal of claim 3 further comprising means connected to said serial output terminal of said second serial storage means for gating signals to said third serial storage means.
Claim 8
Dependent Claim
36 words
The terminal of claim 5 further comprising means for gating signals from said third serial storage means to said output port; and means for gating signals from said first serial storage means to said output port.
Claim 9
Dependent Claim
27 words
The terminal of claim 6 further comprising: means for gating signals from said fourth serial storage means to said input terminal of said second serial storage means.
Claim 10
Dependent Claim
23 words
The terminal of claim 7 further comprising means for gating signals from said fourth serial storage means to said third serial storage means.
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) | 1978-06-23 | 1978-12-23 | 1979-06-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-06-23 | 1982-12-23 | 1983-06-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-06-23 | 1986-12-23 | 1987-06-24 | $7700.00 | Window Closed / Lapsed |