Apparatus and method for identifying multiple transponders
First Claim
1. A method for identifying a plurality of transponders comprising the steps of:
- assigning an unique identification code to each one of said plurality of transponders;
dynamically building and modifying a bit string and transmitting said bit string to said transponders;
permitting responses from those transponders having identification code endings equal to said transmitting bit string;
suppressing responses from those transponders having identification code endings different from said transmitted bit string;
repeating said bit string building, modifying and transmitting step and response permitting and suppressing step until only one transponder response is received and said transponder identified thereby; and
repeating said bit string building, modifying and transmitting step and response permitting and suppressing step until all of said plurality of transponders are identified.
3 Assignments
0 Petitions
Accused Products
Abstract
Apparatus and method for identifying a plurality of transponders (10-16) located within an inquiry field (18) of an interrogation unit (20) are provided. Each transponder (10-16) is assigned an unique identification code, and the interrogation unit (20) dynamically constructs and modifies a bit string used to solicit responses from selected transponder(s) until each transponder (10-16) in the inquiry field (18) is identified. The bit string is transmitted to the transponders, which compares it with the least significant bits of their respective identification codes. A mismatch between the identification code and the bit string results in suppressing the response from the transponder.
293 Citations
22 Claims
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1. A method for identifying a plurality of transponders comprising the steps of:
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assigning an unique identification code to each one of said plurality of transponders; dynamically building and modifying a bit string and transmitting said bit string to said transponders; permitting responses from those transponders having identification code endings equal to said transmitting bit string; suppressing responses from those transponders having identification code endings different from said transmitted bit string; repeating said bit string building, modifying and transmitting step and response permitting and suppressing step until only one transponder response is received and said transponder identified thereby; and repeating said bit string building, modifying and transmitting step and response permitting and suppressing step until all of said plurality of transponders are identified. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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9. A method for identifying a plurality of transponders located in close proximity with one another within an inquiry field of an interrogation unit, comprising the steps of:
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assigning an unique identification code to each of said plurality of transponders; constructing a bit string; transmitting said bit string in an interrogation pulse; silencing those transponders having an identification code ending unequal to said bit string; receiving responses to said interrogation pulse from those transponders having an identification code ending equal to said bit string; modifying said bit string and transmitting said bit string until only one transponder responds and is identified; and repeating said modifying and transmitting bit string step until all of said plurality of transponders are identified. - View Dependent Claims (10, 11, 12, 13, 14, 15, 16, 17, 18, 19)
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20. A transponder system comprising:
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an interrogation unit comprising; a processor dynamically building and modifying a bit string; a transmitter transmitting an interrogation pulse including said bit string receivable within an inquiry field; and a plurality of transponders located in close proximity with one another within said inquiry field, each transponder comprising; a memory storing an unique identification code; a resonant circuit receiving said interrogation pulse, said interrogation pulse including said bit string; a controller comparing said received bit string with least significant bits of said stored identification code; and a de-energizer circuit suppressing said resonant-circuit from transmitting a response in response to said least significant bits of said identification code being unequal to said bit string. - View Dependent Claims (21, 22)
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Specification