US5095425A
Expired / Lapsed
US
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Method and arrangement for data transmission, as well as a station to implement the method having timing periods beginning on successive transitions of data signal
Assignee: US Philips Corp
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Filing: 1990-09-27
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Granted: 1992-03-10
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Expires: 2010-09-27
Abstract
Abstract For data transmission via a data bus in the form of a single-wire bus, to which several stations are connected in parallel, data bits are transmitted singly in a periodic sequence of signals, whereby each period has at least one section in which the transmitted signal indicates the occupancy of the data bus, a further section in which the transmitted signal indicates the value of the data bit, and a section without data, preferably with high potential in the case of an electric data bus, to which the data generated by the individual stations is linked by an OR function. The durations of the individual sections have fixed periods with respect to one another, and from the signal transfer at the beginning of every two successive periods the duration of the period in each station is determined and from the the position of the individual sections is determined in which the signal is sampled on the data bus and the value of the transmitted data bit is determined. In a preferred embodiment, at the beginning of each period a signal transfer is created on the data bus permanently, outside of a data transmission, so that a first section of the period represents a permanent clock pulse on the data bus which synchronizes all the stations. For the signal which indicates the occupancy of the data bus a section is reserved after this which is then followed again by the time period for the data bit. This makes it possible to achieve a data transmission between stations the internal clocks of which exhibit considerable differences, and yet multimaster operation is still possible.
Inventors
- 👤 Feodor W. Hesse
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 06:30
CPC Classifications
H; H04; H04L; H04L12/00; H04L12/28; H04L12/40; H04L12/407; H04L12/417
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
443 words
In a communications network comprising a data bus to which a plurality of stations is connected in a manner that a data signal on the data bus has a first predetermined logic value if any of said stations transmit on the data bus the first logic value and has a second predetermined logic value, opposite said first logic value, if none of said stations transmit on the data bus the first logic value, each station comprising means for communicating via said data bus with the other stations utilizing timing periods in a data signal on said data bus, each successive transition in said data signal from said second logic value to said first logic value beginning a new timing period, each timing period having first, second and third part periods with durations in a fixed ratio to one another, for respective first, second and third signal portions of said data signal, the first signal portion having the first logic value when the data bus is occupied for transmission from one of said stations and the second logic value when the data bus is unoccupied, the second signal portion having a logic value indicativ of a transmitted data bit when the data bus is occupied and having said second logic value when the data bus is unoccupied and the third signal portion constantly having the second logic value, a station comprising: receiver timing means for locally determining the time between successive transitions from said second logic value to said first logic value established in said data signal by another of said stations and the position and duration of said first, second and third part periods from said fixed ratio and the positions of said successive transitions from said second logic value to said first logic value; detecting means for detecting the logic values of the first, second and third signal portions in the respective first, second and third part periods determined by the receiver timing means; transmitter timing means for selectively establishing said successive transitions in said data signal from said second logic value to said first logic value; and transmitting means, responsive to the detecting means detecting a first signal portion having the second logic value indicative of the data bus being unoccupied, for transmitting on the data bus to establish in said data signal between said successive transitions from said second logic level to said first logic level a transition from said first logic level to said second logic level positioned such that the first and third signal portions respectively have said first and second logic values and said second signal portion has a logic value indicative of a transmitted data bit.
Claim 2
Dependent Claim
443 words
In a communications network comprising a data bus to which a plurality of stations is connected in a manner that a data signal on the data bus has a first predetermined logic value if any of said stations transmit on the data bus the first logic value and has a second predetermined logic value, opposite said first logic value, if none of said stations transmit on the data bus the first logic value, each station comprising means for communicating via said data bus with the other stations utilizing timing periods in a data signal on said data bus, each successive transition in said data signal from said second logic value to said first logic value beginning a new timing period, each timing period having first, second and third part periods with durations in a fixed ratio to one another, for respective first, second and third signal portions of said data signal, the first signal portion having the first logic value when the data bus is occupied for transmission from one of said stations and the second logic value when the data bus is unoccupied, the second signal portion having a logic value indicativ of a transmitted data bit when the data bus is occupied and having said second logic value when the data bus is unoccupied and the third signal portion constantly having the second logic value, a station comprising: receiver timing means for locally determining the time between successive transitions from said second logic value to said first logic value established in said data signal by another of said stations and the position and duration of said first, second and third part periods from said fixed ratio and the positions of said successive transitions from said second logic value to said first logic value; detecting means for detecting the logic values of the first, second and third signal portions in the respective first, second and third part periods determined by the receiver timing means; transmitter timing means for selectively establishing said successive transitions in said data signal from said second logic value to said first logic value; and transmitting means, responsive to the detecting means detecting a first signal portion having the second logic value indicative of the data bus being unoccupied, for transmitting on the data bus to establish in said data signal between said successive transitions from said second logic level to said first logic level a transition from said first logic level to said second logic level positioned such that the first and third signal portions respectively have said first and second logic values and said second signal portion has a logic value indicative of a transmitted data bit.
Claim 3
Dependent Claim
36 words
The station as claimed in claim 1, wherein said receiver timing means, said detecting means, said transmitter timing means and said transmitting means are comprised by a microprocessor which is controlled by a permanently entered program.
Claim 4
Dependent Claim
47 words
The station as claimed in claim 1, in which said data bus comprises a two-wire line and further comprising a power supply for said station connected to said two-wire line by way of a smoothing element whereby power is derived from said data signal on said bus.
Claim 5
Dependent Claim
319 words
The station of claim 1 wherein said detecting means and said receiver timing means comprise a clock pulse generator, and a counting device means including a first counter connected to the clock pulse generator for beginning to count from an initial first counter value, with clock pulses from said clock pulse generator, at a moment following an occurrence of said transition in said data signal from said second logic value to said first logic value after transferring a final first counter value said first counter means has reached at this moment into a memory, the counting device means further comprising means responsive to the position of the first counter means for: on said first counter reaching a first counter position which is equal to a predetermined first fraction of the difference between said final and initial counter values which in accordance with said fixed ratio corresponds to a time within the first part period, generating a first sampling signal (S1) to a first sampling circuit responsive to the first sampling signal (S1), said first sampling circuit comprising means for generating a continuous local "bus occupied" signal for as long as said data signal has the first logic value simultaneously with each succeeding first sampling signal (S1); on said first counter reaching a second counter position which is equal to a predetermined second fraction of the difference between the final and initial counter values which in accordance with said fixed ratio corresponds to a time within the second part period, generating a second sampling signal (S2), and when the local "bus occupied" signal is present, feeding said second sampling signal (S2) to a second sampling circuit which also receives said data signal, said second sampling circuit comprising means for generating at a data output of said second sampling circuit a data bit value indicative of the logic value which the data signal has simultaneously with said second sampling signal (S2).
Claim 6
Dependent Claim
73 words
The station as claimed in claim 4, wherein the first part period is divided into first and second sub-periods, said transmitter timing means establishing said successive transitions in said data signal from said second logic value to said first logic value by transmitting on the data bus a signal corresponding to the first logic value during said first sub-period, and said first sampling signal (S1) occurs at a time within said second sub-period.
Claim 7
Dependent Claim
24 words
The station as claimed in claims 4 or 5 in which said predetermined first and second fractions differ by an inverse power of two.
Claim 8
Dependent Claim
183 words
The station as claimed in claims 4 or 5, wherein the initial value of said first counter is zero, said first and second fractions are respectively 3/8 and 5/8 and in which said counting device means further comprises second, third and fourth counters interconnected with said first counter to form said memory means for at said moment causing setting said second counter to the final value of said first counter shifted by three binary places and said third and fourth counters to the final value of said first counter shifted by two binary places, and wherein said second, third, and fourth counters count down to a zero position with the clock signal of said clock pulse generator, whereby said second counter starts counting down at said moment and said third and fourth counters start counting down when the zero positions of the second and third counters, respectively, are reached, and the reaching of said zero position of said third counter generates said first sampling signal (S1) and the reaching of said zero position of said fourth counter generates said second sampling signal (S2).
Claim 9
Dependent Claim
107 words
The station as claimed in claims 4 or 5, in which said coutning device means further comprises: a second counter which counts backwards with said clock signal of said clock pulse generator and is set to the final counter value of said first counter shifted by three binary places and each time a zero position of said second counter is reached, said coutning device means generates a counting pulse; a third counter for counting with said counting pulses; and means responsive to the counting position of said third counter for generating in said first part period, said first sampling signal (S1) and said second sampling signal (S2).
Claim 10
Dependent Claim
382 words
In a communication network having a data bus via which a plurality of stations are connected in a manner that a data signal on the data bus has a first predetermined logic value if any of said stations transmit on the data bus the first logic value and has a second predetermined logic value, opposite said first logic value, if none of said stations transmit on the data bus the first logic value, a method for transmitting data bits from a station ready to transmit data to a station addressed by said data bits, in which successive timing periods are commenced by each transition in said data signal from said second logic value to said first logic value, each timing period having three part periods successive to one another and with durations in a fixed ratio to one another, said method comprising the following steps by the station ready to transmit data for each data bit to be transmitted: detecting when said data bus has an unoccupied state by detecting when said data signal has the second logic value during a predetermined time period; after said detecting, starting data transmission by: first transmitting a signal on the data bus having the first logic value, indicating an occupied state of the bus, during the first part period of a said timing period; second transmitting a signal on the data bus during the second part period of said timing period having the value of the data bit to be transmitted; and third transmitting a signal on the data bus having the second logic value during the third part period of said timing period; and the following steps by at least one other of said stations: first determining the duration of said timing period and the position of said three part periods therein from said transitions in said data signal on the data bus occurring at the beginning of two successive ones of said timing periods; second determining from the signal present on the data bus during the first part period whether the data bus has an unoccupied state or an occupied state; and third determining, when said data bus has an occupied state, the logic value of the transmitted data bit from the signal present on the data bus during the second part period.
Claim 11
Dependent Claim
382 words
In a communication network having a data bus via which a plurality of stations are connected in a manner that a data signal on the data bus has a first predetermined logic value if any of said stations transmit on the data bus the first logic value and has a second predetermined logic value, opposite said first logic value, if none of said stations transmit on the data bus the first logic value, a method for transmitting data bits from a station ready to transmit data to a station addressed by said data bits, in which successive timing periods are commenced by each transition in said data signal from said second logic value to said first logic value, each timing period having three part periods successive to one another and with durations in a fixed ratio to one another, said method comprising the following steps by the station ready to transmit data for each data bit to be transmitted: detecting when said data bus has an unoccupied state by detecting when said data signal has the second logic value during a predetermined time period; after said detecting, starting data transmission by: first transmitting a signal on the data bus having the first logic value, indicating an occupied state of the bus, during the first part period of a said timing period; second transmitting a signal on the data bus during the second part period of said timing period having the value of the data bit to be transmitted; and third transmitting a signal on the data bus having the second logic value during the third part period of said timing period; and the following steps by at least one other of said stations: first determining the duration of said timing period and the position of said three part periods therein from said transitions in said data signal on the data bus occurring at the beginning of two successive ones of said timing periods; second determining from the signal present on the data bus during the first part period whether the data bus has an unoccupied state or an occupied state; and third determining, when said data bus has an occupied state, the logic value of the transmitted data bit from the signal present on the data bus during the second part period.
Claim 12
Dependent Claim
58 words
The method as claimed in claim 9 further including the step by said station ready to transmit data in at least one preparatory timing period following said detecting and preceding said starting data transmission, of transmitting a signal on the data bus having the first logic value only during the first part period of the preparatory time period.
Claim 13
Dependent Claim
97 words
The method as claimed in claim 9, wherein said first part period is divided into first and second sub-periods and further including the step of transmitting by one of said stations of a signal on the data bus having the first logic value during the first sub-period in order to establish in said data signal said transitions from the second logic value to the first logic value, and wherein said detecting and first transmitting by the station ready to transmit data and said first determining by said at least one other station are during the second sub-period.
Claim 14
Dependent Claim
31 words
The method as claimed in claim 11, wherein said second and third part periods and the first and second sub-periods have equal time durations each of 1/4 of said timing period.
Claim 15
Dependent Claim
31 words
The method as claimed in claim 11, wherein said steps of first determining and second determining are undertaken approximately in the middle of the second sub-period and second part period, respectively.
Claim 16
Dependent Claim
98 words
The method as claimed in claim 11, wherein the station ready to transmit sequentially repeats said first through third transmitting steps until a sufficient number of data bits have been transmitted to identify the station being addressed, and wherein following said transmission of said sufficient number of data bits, the station being addressed transmits a signal on the data bus having the first logic value during the second part period of at least one timing period while said station ready to transmit transmits a signal having the second logic value during said second part period of this period.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1995-03-10 | 1995-09-09 | 1996-03-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1999-03-10 | 1999-09-09 | 2000-03-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2003-03-10 | 2003-09-09 | 2004-03-10 | $7700.00 | Window Closed / Lapsed |