Programmable transponder

• US 5,532,686 A
• Filed: 10/04/1993
• Issued: 07/02/1996
• Est. Priority Date: 07/29/1991
• Status: Expired due to Term

• Current Assignee: Bio Medic Data Systems Incorporated (ATS Corp.)
• Original Assignee: Bio Medic Data Systems Incorporated (ATS Corp.)
• Inventors: Burne, John, Ellwood, David, Urbas, Donald J.
• Primary Examiner(s): Swann, Glen
• Assistant Examiner(s): HILL, ANDREW M
• Application Number:
  US08/131,275
• Time in Patent Office: 1,002 Days
• Field of Search: 340/825.34, 340/825.54, 340/825.69, 340/825.71, 340/825.72, 340/531, 340/568, 340/571, 340/572, 342/44, 342/51, 235/382.5, 235/383, 235/385, 235/376, 235/379, 235/380, 364/478
• US Class Current: 340/10.51
• CPC Class Codes: G07C 9/21 having a variable access code
• CPC Class Codes: G07C 9/28 the pass enabling tracking or indicating presence

Abstract

A passive transponder has a power antenna which receives a power signal and a communication antennas which receives a communication signal. An information generating circuit creates a second communication signal in response to the first communication signal and outputs the second communication signal through the communication antenna. The information generating circuit is powered by a power supply which outputs a voltage for powering the transponder in response to the power signal. The information generating circuit includes a reprogrammable EEPROM and an EEPROM interface circuit which operates on the EEPROM by retrieving and storing data in response to the instructions and data contained within the first communication signal.

Claims

1. A passive transponder for inductively receiving a power signal and a first communication signal and transmitting a second communication signal in response thereto comprising communication antenna means for receiving said first communication signal;

power antenna means for receiving said power signal;

information generating means for creating said second communication signal in response to said first communication signal, power supply means for directly providing said power signal to said information generating means, said information generating means utilizing said power signal as a clock to generate said second communication signal and said communication antenna means outputting said second communication signal synchronous with said power signal.

2. The passive transponder of claim 1, wherein said first communication signal has a first frequency and said communication antenna means is tuned to said first frequency.

3. The passive transponder of claim 2, wherein said power signal has a second frequency less than said first frequency.

4. The passive transponder of claim 3, wherein said second frequency is less than 10 KHz.

5. The passive transponder of claim 2, wherein said communication antenna means includes a tuned coil and a modulation coil operatively coupled to said tuned coil when said transponder is outputting said second communication signal and is inoperatively coupled to said tuned coil when said transponder is receiving said first communication signal.

6. The passive transponder of claim 3, further comprising clock generating means for producing a receive clock signal and a transmit clock signal as a function of said power signal wherein said information generating means receives said first communication signal in response to said receive clock signal, said receive clock signal having a third frequency and outputting said second communication signal by clocking out said second communication signal in response to said transmit signal, said transmit signal having a fourth frequency.

7. The passive transponder of claim 6, wherein said third frequency of said receive clock signal is an integer multiple of said second frequency.

8. The passive transponder of claim 1, further comprising reprogrammable memory means for storing data received by said communication antenna means, said reprogrammable memory means having a plurality of memory addresses, and memory interface means for selectively addressing an address of said reprogrammable memory means in response to said first communication signal and operating on said address of said memory selected in response to said first communication signal.

9. The passive transponder of claim 8, wherein said information generating means further includes clock generating means for producing a receive clock signal and a transmit clock signal, said clock generating means enabling said memory interface means to receive said first communication signal in response to said receive clock signal and to output said second communication signal in response to said transmit clock signal, said receive clock signal having a frequency different than said transmit clock signal.

10. The passive transponder of claim 9, wherein said first communication signal includes instructions for selecting an address of said reprogrammable memory means and operating on said address.

11. The passive transponder of claim 10, wherein said first communication signal further includes data to be stored in said reprogrammable memory means at said selected address.

12. The passive transponder of claim 10, wherein said instructions are one of WRITE instructions and READ instructions.

13. The passive transponder of claim 8, further comprising operation inhibiting means for preventing operation on said memory if said power supplied by said power supply means is below a predetermined level.

14. The passive transponder of claim 12, wherein said second communication signal includes data stored in said memory means.

15. The passive transponder of claim 14, wherein said second communication signal further includes instructions corresponding to the status of said reprogrammable memory means and memory interface means.

16. The passive transponder of claim 8, wherein said reprogrammable memory means is an EEPROM.

17. The passive transponder of claim 11, wherein said memory interface means reprograms said reprogrammable memory means in response to the instructions of said first communication means by entering the data of said first communication signal at the address of said reprogrammable memory means selected by said communication signal.

18. A passive transponder comprising communication antenna means for inductively receiving a first communication signal and inductively transmitting a second communication signal in response thereto, said first and second communication signals each including data and instructions, reprogrammable memory means for storing data received by said transponder, said reprogram table memory means having a plurality of memory addresses;

information generating means for creating said second communication signal in response to said first communication signal, said information generating means including memory interface means for selectively addressing an address of said reprogrammable memory in response to said first communication signal and operating on said selectively addressed memory address in response to said first communication signal.

19. The passive transponder of claim 18, wherein said information generating means further includes clock generating means, said clock generating means including a receive clock and a transmit clock, said clock generating means enabling said memory interface to receive said first communication signal in response to said receive clock and to output said second communication signal in response to said transmit clock, said receive clock having a frequency different than said transmit clock.

20. The passive transponder of claim 18, wherein said first communication signal includes instructions for selecting an address of said memory and operating on said address.

21. The passive transponder of claim 20, wherein said first communication signal further includes data to be stored in said memory means at said selected address.

22. The passive transponder of claim 18, wherein said second communication signal includes data stored in said reprogrammable memory means.

23. The passive transponder of claim 22, wherein said second communication signal further includes instructions corresponding to the status of said reprogrammable memory means and memory interface means.

24. The passive transponder of claim 18, wherein said reprogrammable memory means is an EEPROM.

25. The passive transponder of claim 21, wherein said memory interface means reprograms said reprogrammable memory means in response to the instructions of said first communication means by entering the data of said first communication signal at the address of said reprogrammable memory means selected by said communication signal.