EP1017005A2
Expired / Lapsed
EP
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A system and method for communicating with multiple transponders
Assignee: Texas Instruments Inc
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Filing: 1999-11-30
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Granted: —
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Expires: 2019-11-30
Abstract
Abstract The object of the invention is a system and method for identifying and communicating with a plurality of transponders which are at the same time in the same interrogation field. The system is based on an interrogator which sends interrogation bursts in a periodical manner, and transponders which send the response back with a random delay related to the end-of-burst event. The system is primarily suitable for passive (no additional power supply) transponders, but can also be used for active transponders. <IMAGE>
Inventors
- 👤 Pourang Mahdavi
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-24 15:49
CPC Classifications
G; G06; G06K; G06K7/00; G06K7/10; G06K7/10009; G06K7/10019; G06K7/10029; G06K7/10059; G06K7/0008
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
90 words
A method of reading a plurality of transponders comprising: (a) pulsing of an interrogation field which is sent by a reader, generating End Of
Burst signals as a time base, (b) generating a Request To Send signal with a delay after the End Of Burst
signals by each of the plurality of transponders, (c) providing a second End Of Burst signal by the reader after receiving a valid
Request To Send signal from one of the plurality of transponders and (d) transmitting the main data by one of the transponders.
Claim 2
Dependent Claim
30 words
A method as claimed in claim 1, wherein the one transponder enters a sleep mode
after the data transmission is acknowledged by another End Of Burst signal from the reader.
Claim 3
Dependent Claim
28 words
A method as claimed in claim 1 or claim 2, including the repetition of the steps (c)
and (d) for the remaining transponders of the plurality of transponders.
Claim 4
Independent Claim
48 words
A method as claimed in any one of claims 1 to 3 and including a step (e) of causing
an invalid Request To Send signal, on the occurrence of a collision at the reader, by
encoding a random pattern into the Request To Send signals of the transponders.
Claim 5
Independent Claim
19 words
A method as claimed in any one of claims 1 to 4, wherein the interrogation field is
pulsed periodically.
Claim 6
Independent Claim
94 words
A system for reading a plurality of transponders comprising: means for effecting a pulsing interrogation field which is sent by a reader, generating
End Of Burst signals as a time base, means for generating a Request To Send signal with a delay after the End Of Burst
signal by each of the plurality of transponders, means for providing a second End Of Burst signal by the reader after receiving a
valid Request To Send signal from one of the plurality of transponders and means for transmitting the main data by one of the transponders.
Claim 7
Dependent Claim
30 words
A system as claimed in claim 6, wherein the one transponder enters a sleep mode
after the data transmission is acknowledged by another End Of Burst signal from the reader.
Claim 8
Dependent Claim
43 words
A method as claimed in claim 6 or claim 7, including means for causing an invalid
Request To Send signal, on the occurrence of a collision at the reader, by encoding a
random pattern into the Request To Send signals of the transponders.
Claim 9
Independent Claim
19 words
A method as claimed in any one of claims 6 to 8, wherein the interrogation field is
pulsed periodically.
Claim 10
Dependent Claim
75 words
A reader for a reader-transponder system including: means for transmitting a first burst signal, means for receiving a response signal from a transponder responding to the first burst
signal, means for transmitting a second burst signal on receipt of the transponder response
signal, means for receiving data signals from the transponder responding to the second burst
signal and means for transmitting a third burst signal acknowledging the receipt of the data
signals from the transponder.
Claim 11
Dependent Claim
75 words
A transponder for a reader-transponder system including: means for detecting a first burst signal from a reader, means for transmitting a response signal in response to the first burst signal, means for detecting a second burst signal from the reader, means for transmitting data signals in response to the second burst signal, means for detecting a third burst signal from the reader and means for deactivating the transponder in response to the third burst signal.
References Cited (Backward Citations)
No citation records indexed.
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