Electronic card identification methods

• US 6,328,218 B1
• Filed: 10/28/1999
• Issued: 12/11/2001
• Est. Priority Date: 10/30/1998
• Status: Expired due to Term

• Current Assignee: STMicroelectronics SA (STMicroelectronics NV)
• Original Assignee: STMicroelectronics SA (STMicroelectronics NV)
• Inventors: Gaultier, Jean-Marie
• Primary Examiner(s): Pitts, Harold I.
• Application Number:
  US09/428,862
• Time in Patent Office: 775 Days
• Field of Search: 235/492, 235/384, 235/380, 370/95.1, 370/95.2
• US Class Current: 235/492
• 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 method is provided for identifying electronic cards. According to the method, an interrogation message is sent to the electronic cards, and at least two different types of markers are sent to the electronic cards. The markers of the first type determine the time slots in the sequence, and the markers of the second type cause the electronic cards to change to predetermined states. In a preferred method, the identification method is interrupted when a marker of the second type is sent. Also provided is a method of identifying electronic cards by receiving an interrogation message from an interrogation unit, and at least two different types of markers are received from the interrogation unit. The markers of the first type determine the time slots in the sequence, and the markers of the second type cause the electronic cards to change to predetermined states. Additionally, communication systems of the type in which an interrogation unit identifies electronic cards are provided.

Claims

1. A method of identifying electronic cards of the type in which the electronic cards respond to an interrogation message from an interrogation unit by sending response messages in specific time slots within a sequence of time slots, said method comprising the steps of:

sending the interrogation message to the electronic cards; and

sending at least two different types of markers to the electronic cards,

wherein the markers of the first type indicate the start of each of the time slots in the sequence, and

the markers of the second type cause the electronic cards to change to predetermined states.

2. The method as defined in claim 1, further comprising the step of interrupting the identification method when a marker of the second type is sent.

3. The method as defined in claim 1, further comprising the step of setting at least one of the electronic cards to a standby state after a marker of the second type is sent.

4. The method as defined in claim 1, further comprising the step of interrupting the identification method and setting at least some of the electronic cards to a standby state after a marker of the second type is sent.

5. The method as defined in claim 1, further comprising the step of activating at least one of the electronic cards and setting the remaining electronic cards to a standby state after a marker of the second type is sent.

6. The method as defined in claim 1, further comprising the step of activating at least one of the electronic cards, setting the remaining electronic cards to a standby state, and sending at least one command message to the activated electronic cards after a marker of the second type is sent.

7. The method as defined in claim 1, wherein each of the markers is a binary word encoded on p bits, where p is greater than or equal to 1.

8. A method of identifying electronic cards of the type in which the electronic cards respond to an interrogation message from an interrogation unit by sending response messages in specific time slots within a sequence of time slots, said method comprising the steps of:

receiving the interrogation message from the interrogation unit; and

receiving at least two different types of markers from the interrogation unit,

wherein the markers of the first type indicate the start of each of the time slots in the sequence, and

the markers of the second type cause the electronic cards to change to predetermined states.

9. The method as defined in claim 8, further comprising the step of setting at least one of the electronic cards to a standby state when a marker of the second type is received.

10. The method as defined in claim 8, further comprising the step of activating at least one of the electronic cards and setting the remaining electronic cards to a standby state when a marker of the second type is received.

11. The method as defined in claim 8, further comprising the step of activating at least one of the electronic cards, setting the remaining electronic cards to a standby state, and receiving at least one command message for the activated electronic cards after a marker of the second type is received.

12. The method as defined in claim 8, wherein each of the markers is a binary word encoded on p bits, where p is greater than or equal to 1.

13. A communication system including an interrogation unit for identifying electronic cards, said interrogation unit comprising:

means for sending an interrogation message to the electronic cards; and

means for sending at least two different types of markers to the electronic cards,

wherein the markers of the first type indicate the start of each time slot in a sequence of time slots within which the interrogation unit waits for possible response messages from the electronic cards, and

the markers of the second type cause the electronic cards to change to predetermined states.

14. The communication system as defined in claim 13, wherein said interrogation unit further comprises means for interrupting electronic card identification when a marker of the second type is sent.

15. The communication system as defined in claim 13, wherein said interrogation unit further comprises means for activating at least one of the electronic cards after a marker of the second type is sent.

16. The communication system as defined in claim 13, wherein said interrogation unit further comprises means for activating at least one of the electronic cards and sending at least one command message to the activated electronic cards after a marker of the second type is sent.

17. The communication system as defined in claim 13, wherein each of the markers is a binary word encoded on p bits, where p is greater than or equal to 1.

18. A communication system of the type in which an interrogation unit identifies electronic cards, each of said electronic cards comprising:

means for receiving an interrogation message from the interrogation unit; and

means for receiving at least two different types of markers from the interrogation unit,

wherein the markers of the first type indicate the start of each time slot in a sequence of time slots within which the interrogation unit waits for possible response messages from the electronic cards, and

the markers of the second type cause the electronic cards to change to predetermined states.

19. The communication system as defined in claim 18, wherein each of said electronic cards further comprises means for selectively setting the electronic card to a standby state when a marker of the second type is received.

20. The communication system as defined in claim 18, wherein each of said electronic cards further comprises means for selectively activating the electronic card or setting the electronic card to a standby state after a marker of the second type is received.

21. The communication system as defined in claim 18, wherein each of said electronic cards further comprises means for receiving at least one command message when the electronic card is activated.

22. The communication system as defined in claim 18, wherein each of the markers is a binary word encoded on p bits, where p is greater than or equal to 1.

23. The communication system as defined in claim 18, wherein each of said electronic cards further comprises:

means for interpreting received information; and

means for determining the type of a received marker.