US3866217A
Expired / Lapsed
US
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Monitoring transmission link by comparing pseudorandom signals
Assignee: Currier Smith Corp
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Filing: 1972-12-26
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Granted: 1975-02-11
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Expires: 1992-12-26
Abstract
Abstract A monitoring remote location has alarm sensors and a data transmitter for transmitting alarm and pseudorandom number signals over a direct line to a data detector at the monitoring central location. The monitoring location has a pseudorandom number signal generator that generates at essentially the same time the same number signals generated at the monitored location. The portable pseudorandom number signal generator at the monitored location is first brought to the monitoring location. There both pseudorandom number signal generators receive the same initial number signal at the same time to simultaneously produce the same pseudorandom sequence of digital numbers. The portable pseudorandom number generated is then taken to the monitored location and coupled to the data transmitter which also receives alarm or other signals, if any. The data detector at the monitoring location then compares the sequence of number signals received over the direct line with those locally produced by its pseudorandom number signal generator to provide a line failure signal when the number signals thus compared are not the same for a predetermined time interval.
Inventors
- 👤 Jr Victor A Bennett
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 19:06
CPC Classifications
G; G08; G08B; G08B29/00; G08B29/02; G08B29/06
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
122 words
A method of monitoring a communication link to detect a change from a normal to an abnormal condition in said communication link which method includes the steps of, establishing the same initial conditions in like first and second pseudorandom signal generating means at a first location to provide first and second like pseudorandom signals respectively occurring at substantially the same time, transporting said second pseudorandom signal generating means to a second location, transmitting said second pseudorandom signal over said communication link between said second location and said first location, comparing the transmitted second pseudorandom output signal with said first pseudorandom output signal at said first location, and providing an indication when the latter signals differ for more than a predetermined time interval.
Claim 2
Independent Claim
122 words
A method of monitoring a communication link to detect a change from a normal to an abnormal condition in said communication link which method includes the steps of, establishing the same initial conditions in like first and second pseudorandom signal generating means at a first location to provide first and second like pseudorandom signals respectively occurring at substantially the same time, transporting said second pseudorandom signal generating means to a second location, transmitting said second pseudorandom signal over said communication link between said second location and said first location, comparing the transmitted second pseudorandom output signal with said first pseudorandom output signal at said first location, and providing an indication when the latter signals differ for more than a predetermined time interval.
Claim 3
Dependent Claim
24 words
A method of monitoring a communication link in accordance with claim 1 wherein said first and second pseudorandom signals are representative of digital numbers.
Claim 4
Dependent Claim
48 words
A method of monitoring a communication link in accordance with claim 1 wherein the step of establishing the same initial conditions in said first and second psuedorandom signal generating means includes injecting the same unknown pseudorandom number signal into both said first and second pseudornadom signal generating means.
Claim 5
Dependent Claim
54 words
A method of monitoring a communication link in accordance with claim 3 which method includes the steps of establishing the same unknown randomly generated number signal in a primer source, and coupling said unknown signal from said primer source to both said first and second pseudorandom signal generating means at substantiaLly the same time.
Claim 6
Dependent Claim
123 words
Apparatus for monitoring a communication link to detect a change from a normal to an abnormal condition in said communication link comprising, first and second like pseudorandom signal generating means for producing first and second like psuedorandom signals, means defining a communications link for transmitting said second pseudorandom signal from a second location to a first location of said first source, data transmitting means at said second location for transmitting said second pseudorandom signal over said communications link to said first location, and data detecting means at said first location for comparing said first pseudorandom signal with the transmitted second pseudorandom signal to provide an indication of an unacceptable condition when the latter two signals differ for more than a predetermined time interval.
Claim 7
Dependent Claim
123 words
Apparatus for monitoring a communication link to detect a change from a normal to an abnormal condition in said communication link comprising, first and second like pseudorandom signal generating means for producing first and second like psuedorandom signals, means defining a communications link for transmitting said second pseudorandom signal from a second location to a first location of said first source, data transmitting means at said second location for transmitting said second pseudorandom signal over said communications link to said first location, and data detecting means at said first location for comparing said first pseudorandom signal with the transmitted second pseudorandom signal to provide an indication of an unacceptable condition when the latter two signals differ for more than a predetermined time interval.
Claim 8
Dependent Claim
84 words
Apparatus in accordance with claim 5 wherein said pseudorandom signal generating means comprise means for generating digital pseudorandom signals representative of digital numbers and further comprising, prime pseudorandom signal generating means for providing an unknown pseudorandom number signal as an initial condition signal, and means for storing said unknown pseudorandom number signal in both said first and second pseudorandom signal generating means at substantially the same time so that they thereafter provide the same sequence of digital number signals at substantially the same time.
Claim 9
Dependent Claim
136 words
Apparatus in accordance with claim 6 wherein said first and second pseudorandom signal generating means each comprise, first memory means for storing said unknown pseudorandom number signal, second memory means for storing a multiplicand digital number signal, third memory means for accumulating partial product signals, means for successively multiplying said multiplicand digital number signal by each digit of the number signal stored in said first memory means to provide a succession of partial product signals, means for adding the partial product signals to the digital number signal stored in said third memory means to provide an accumulated partial product signal, means for storing the first through the penultimate of said accumulated partial product signals in said third memory means, and means for storing the last of said accumulated partial product signals in said second memory means.
Claim 10
Dependent Claim
62 words
Apparatus in accordance with claim 7 and further comprising means for transmitting a predetermined sequence of digital number bit signals stored in said second memory means of said second pseudorandom signal generating means to said first location, and means for comparing the latter sequence with a corresponding sequence then stored in said second memory means of said first pseudorandom signal generating means.
Claim 11
Dependent Claim
143 words
A method of monitoring a communication link in accordance with claim 3 and further including the steps of storing said unknown pseudorandom number signal in first memory means of said first and second signal generating means, storing a multiplicand digital number signal in second memory means of said first and second generating means, successively multiplying both said multiplicand digital number signals by each digit of the number signal stored in each first memory means to provide a succession of partial product signals, adding the partial product signals to digital number signals stored in third memory means of said first and second signal generating means to provide an accumulated partial product signal, storing the first through the penultimate of said accumulated partial product signals in said third memory means, and storing the last of said accumulated partial product signals in said second memory means.
Claim 12
Independent Claim
114 words
A method of generating pseudorandom digital signals which method includes the steps of storing a multiplier digital number signal in first memory means, storing a multiplicand digital number signal In second memory means, successively multiplying said multiplicand digital number signal by each digit of the number signal stored in said first memory means to provide a succession of partial product signals, adding the partial product signals to digital number signals stored in third memory means to provide an accumulated partial product signal, storing the first through the penultimate of said accumulated partial product signals in said third memory means, and storing the last of said accumulated partial product signals in said second memory means.
Claim 13
Independent Claim
114 words
A method of generating pseudorandom digital signals which method includes the steps of storing a multiplier digital number signal in first memory means, storing a multiplicand digital number signal In second memory means, successively multiplying said multiplicand digital number signal by each digit of the number signal stored in said first memory means to provide a succession of partial product signals, adding the partial product signals to digital number signals stored in third memory means to provide an accumulated partial product signal, storing the first through the penultimate of said accumulated partial product signals in said third memory means, and storing the last of said accumulated partial product signals in said second memory 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) | 1978-02-10 | 1978-08-12 | 1979-02-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-02-10 | 1982-08-12 | 1983-02-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-02-10 | 1986-08-12 | 1987-02-11 | $7700.00 | Window Closed / Lapsed |