US4121208A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Device for increasing the safety with respect to transmission faults in an information transmission system
Assignee: Siemens AG
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Filing: 1977-03-11
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Granted: 1978-10-17
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Expires: 1997-03-11
Abstract
Abstract A device for increasing security with respect to transmission faults in an information transmission system, particularly for the railroad field, in which an interrogation device and a passive response device are movable relative to one another, and the interrogation device transmits an interrogation signal, which can be periodically swept through a predetermined frequency band, preferably in the microwave range, and which during a read operation, receives during several periods from the passive response device, a frequency-selectively reflected interrogation signal, in accordance with a k-digit information item to be transmitted, which signal forms the response signal in which the interrogation device is provided with means for amplifying each response signal, until there is reached a predetermined threshold level of the low-frequency portions of the response signals, which are below the frequency of the periodic interrogation sweep, with the amplification that the low-frequency portions thereafter being so reduced that they do not undesirably exceed the threshold value, and means being provided for preventing a through-connection of a transmitted information item in the presence of a decreasing and/or increasing level of such low-frequency portion.
Inventors
- 👤 Friedbert Becker
- 👤 Wilhelm Grafinger
- 👤 Bernhard Hildebrandt
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 00:51
CPC Classifications
B; B61; B61L; B61L25/00; B61L25/02; B61L25/04; B61L25/045; G; G01; G01S; G01S13/00; G01S13/74; G01S13/75; G01S13/751; G01S13/753
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
213 words
In a device for increasing security with respect to transmission faults in an information-transmission system, particularly for the railroad field, in which an interrogation device and a passive response device are movable relative to one another; the interrogation device transmitting an interrogation signal, which can be periodically swept through a predetermined frequency band, preferably in the microwave range; the interrogation device receiving, during a read operation of at least two periods from the passive response device, a frequency-selectively reflected interrogation signal, in accordance with a k-digit information item to be transmitted; the combination of means for amplifying such a reflected interrogation signal received by the interrogation device; means for monitoring the level of the low-frequency portions of such a reflected interrogation signal lying below the sweep frequency of the interrogation device and for reducing the amplification of said amplifying means if the level of such low frequency portions reaches a predetermined threshold value, whereby such low frequency portions do not undesirably exceed such threshold value; switch means for controlling the through-connection of the response signal to subsequent devices; and control means connecting said monitoring and switch means, for controlling the latter to prevent passage of a transmitted information item in the presence of a decreasing and/or increasing level of such low frequency portion.
Claim 2
Dependent Claim
213 words
In a device for increasing security with respect to transmission faults in an information-transmission system, particularly for the railroad field, in which an interrogation device and a passive response device are movable relative to one another; the interrogation device transmitting an interrogation signal, which can be periodically swept through a predetermined frequency band, preferably in the microwave range; the interrogation device receiving, during a read operation of at least two periods from the passive response device, a frequency-selectively reflected interrogation signal, in accordance with a k-digit information item to be transmitted; the combination of means for amplifying such a reflected interrogation signal received by the interrogation device; means for monitoring the level of the low-frequency portions of such a reflected interrogation signal lying below the sweep frequency of the interrogation device and for reducing the amplification of said amplifying means if the level of such low frequency portions reaches a predetermined threshold value, whereby such low frequency portions do not undesirably exceed such threshold value; switch means for controlling the through-connection of the response signal to subsequent devices; and control means connecting said monitoring and switch means, for controlling the latter to prevent passage of a transmitted information item in the presence of a decreasing and/or increasing level of such low frequency portion.
Claim 3
Dependent Claim
39 words
A device according to claim 1, wherein said monitoring means includes means for providing a signal for indicating the end of a read operation of at least two periods, if a decreasing level of the low-frequency portions takes place.
Claim 4
Dependent Claim
39 words
A device according to claim 1, wherein said monitoring means includes means for providing a signal for indicating the beginning of a read operation of at least two periods, if an increasing level of the low-frequency portions takes place.
Claim 5
Dependent Claim
39 words
A device according to claim 3, wherein said monitoring means includes means for providing a signal for indicating the end of a read operation of at least two periods, if a decreasing level of the low-frequency portions takes place.
Claim 6
Dependent Claim
75 words
A device according to claim 1, wherein said control means comprises a comparator; and said monitoring means comprises a pair of memories and further switching means; the outputs of the memories being connected to respective inputs of the comparator and the output of the latter to said through-connection switch; said further switching means being adapted to alternately connect the inputs of the respective memories for reception of the lower frequency portions of the response signal.
Claim 7
Dependent Claim
39 words
A device according to claim 5, wherein said monitoring means includes means for providing a signal for indicating the end of a read operation of at least two periods, if a decreasing level of the low-frequency portions takes place.
Claim 8
Dependent Claim
39 words
A device according to claim 5, wherein said monitoring means includes means for providing a signal for indicating the beginning of a read operation of at least two periods, if an increasing level of the low-frequency portions takes place.
Claim 9
Dependent Claim
39 words
A device according to claim 7, wherein said monitoring means includes means for providing a signal for indicating the end of a read operation of at least two periods, if a decreasing level of the low-frequency portions takes place.
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) | 1981-10-16 | 1982-04-17 | 1982-10-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-10-16 | 1986-04-17 | 1986-10-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-10-16 | 1990-04-17 | 1990-10-17 | $7700.00 | Window Closed / Lapsed |