Electronic tag binary selection method

• US 20020175806A1
• Filed: 05/25/2001
• Published: 11/28/2002
• Est. Priority Date: 05/25/2001
• Status: Abandoned Application

• Current Assignee: Microchip Technology Incorporated
• Original Assignee: Microchip Technology Incorporated
• Inventors: Duvenhage, Stephanus P.J., Marneweck, Willem J.
• Application Number:
  US09/866,229
• Publication Number:
  US 20020175806A1
• Time in Patent Office: Days
• US Class Current: 340/10.33
• CPC Class Codes: G06K 7/0008 General problems related to the reading of electronic memory record carriers, independent of its reading method, e.g. power transfer

Abstract

A system and method for identifying tags with a reader, wherein the tags have unique tag identification codes, having a transmitter of a wake-up signal from the reader to a tag within a field of the reader; a transmitter of a signal corresponding to an initial portion of the tag identification code from the tag to the reader; a transmitter of an initial acknowledgement signal responsive to the signal corresponding to the initial portion of the tag identification code; and a recorder in the reader of an initial portion of a tag confirmation code corresponding to the initial acknowledgement signal. The system send and acknowledges subsequent portions of the identification codes from the tags. If a tag does not receive an acknowledgement of its code, the tag becomes inactive. The system continues until only one tag remains active and transmits its entire code for acknowledgement. This tag is selected.

Claims

1. A method for identifying tags with a reader, wherein the tags have unique tag identification codes, said method comprising:

transmitting a wake-up signal from the reader to a tag within a field of the reader;

transmitting a signal corresponding to an initial portion of the tag identification code from the tag to the reader;

transmitting from the reader to the tag an initial acknowledgement signal responsive to the signal corresponding to the initial portion of the tag identification code; and

storing in the reader an initial portion of a tag confirmation code corresponding to the initial acknowledgement signal.

2. A method as claimed in claim 1, further comprising:

transmitting to the reader a signal corresponding to a subsequent portion of the tag identification code from the tag, wherein the initial portion of the tag identification code for the tag has been acknowledged by the acknowledgement signal;

transmitting from the reader to the tag a subsequent acknowledgement signal responsive to the signal corresponding to the subsequent portion of the tag identification code; and

storing in the reader a subsequent portion of the tag confirmation code corresponding to the subsequent acknowledgement signal.

3. A method as claimed in claim 2, further comprising:

determining whether the number of signals corresponding to portions of the tag identification code sent to the reader from the tag equals the total number of tag identification code portions.

4. A method as claimed in claim 2, further comprising:

transmitting a tag identification confirmation signal from the reader to the tag.

5. A method as claimed in claim 1, further comprising:

deactivating the tag within the field upon the tag'"'"'s reception of an acknowledgement signal from the reader which does not acknowledge a just-transmitted signal corresponding to a portion of the tag identification code from the tag.

6. A method as claimed in claim 1, wherein the initial acknowledgement signal acknowledges a prioritized tag.

7. A method as claimed in claim 1, wherein said transmitting a signal corresponding to an initial portion of the tag identification code from the tag to the reader comprises transmitting a plurality of signals corresponding to initial portions of a plurality of tag identification codes from a plurality of tags.

8. A method for identifying tags with a reader, said method comprising:

a) transmitting a wake-up signal from the reader to a tag within a field of the reader;

b) transmitting a signal corresponding to an initial portion of a tag identification code from a tag to the reader, wherein all tags have unique tag identification codes;

c) transmitting from the reader to a tag an acknowledgement signal responsive to the signal corresponding to the initial portion of the tag identification code;

d) storing in the reader a portion of a tag confirmation code corresponding to the acknowledgement signal;

e) deactivating a tag in the field upon the tag'"'"'s reception of an acknowledgement signal from the reader which does not acknowledge a just-transmitted signal corresponding to a portion of the tag identification code from the tag;

f) repeating steps b), c), d) and e) with respect to subsequent portions of the tag identification code for a tag in the field having an initial portion of the tag identification code which has been acknowledged by the acknowledgement signal; and

g) transmitting a tag selection signal to a tag in the field upon compilation of the tag confirmation code.

9. A method as claimed in claim 8, wherein said transmitting from the reader to a tag an acknowledgement signal responsive to the signal corresponding to the initial portion of the tag identification code acknowledges a high priority tag.

10. A method as claimed in claim 8, further comprising:

determining whether the number of signals corresponding to portions of the tag identification code sent to the reader from a tag in the field equals the total number of tag identification code portions.

11. A method as claimed in claim 8, further comprising:

deactivating the only remaining active tag in the field after transmission of the tag selection signal.

12. A method as claimed in claim 8, further comprising:

repeating steps a), b), c), d), e) and f) to select an additional tag in the field.

13. A method as claimed in claim 8, wherein said transmitting a signal corresponding to an initial portion of a tag identification code from a tag to the reader, wherein all tags have unique tag identification codes comprises transmitting a plurality of signals corresponding to an initial portion of a tag identification code from a plurality of tags.

14. A method as claimed in claim 8, further comprising:

h) communicating with the selected tag via a command set.

16. A system as claimed in claim 15, wherein the tags switch from the active mode to the inactive mode upon receipt of an acknowledgement signal transmission from the reader which does not acknowledge their last transmitted signal corresponding to a portion of their tag identification code.

17. A system as claimed in claim 15, wherein the tags remain in the active mode upon receipt of an acknowledgement signal transmission from the reader which does acknowledges their last transmitted signal corresponding to a portion of their tag identification code.

18. A system as claimed in claim 17, wherein upon receipt of an acknowledgement signal transmission from the reader which does acknowledges their last transmitted signal corresponding to an initial portion of their tag identification codes, the tags transmit a signal corresponding to a subsequent portion of their tag identification codes.

19. A system as claimed in claim 15, further comprising a counter of the number of portions of the tag identification code transmitted by tags in the field.

20. A system as claimed in claim 15, wherein said reader transmits an identification confirmation signal from the reader to a tag in the field, once all tag identification code portions are received from the tag.

21. A system as claimed in claim 15, wherein said reader transmits an acknowledgement signal to acknowledge tag transmitted signals corresponding to high priority portions of tag identification codes, whereby higher priority tags are selected before lower priority tags.

15. A system for identifying objects within a field, said system comprising:

a reader comprising a transmitter, a receiver and a processor, wherein the transmission range of the transmitter and receiver define the field;

a plurality of tags each comprising a transmitter, a receiver and a microprocessor, wherein the tags are attachable to the objects to be identified, wherein each tag has a unique tag identification code and all codes are the same length, wherein the tags operate in active and inactive modes;

wherein said reader transmits a wake-up signal from the reader to all tags in the field, whereby all tags in the field are made to be in the active mode;

wherein all active tags within the field transmit a signal corresponding to an initial portion of their tag identification codes to the reader;

wherein said reader transmits to all tags in the field an acknowledgement signal responsive to the tag signals corresponding to initial portions of the tag identification codes; and

wherein said reader stores an initial portion of a tag confirmation code corresponding to an acknowledgement signal.