Transponder maintenance mode method

• US 5,686,920 A
• Filed: 06/07/1995
• Issued: 11/11/1997
• Est. Priority Date: 04/06/1994
• Status: Expired due to Term

• Current Assignee: Texas Instruments, Inc.
• Original Assignee: Texas Instruments, Inc.
• Inventors: Hurta, Dwaine S., Frazee, Francis B.
• Primary Examiner(s): Sotomayor, John B.
• Application Number:
  US08/482,350
• Time in Patent Office: 888 Days
• Field of Search: 342/42, 342/44, 342/50, 342/51
• US Class Current: 342/42
• CPC Class Codes: B61L 25/048 using programmable tags
• CPC Class Codes: G01S 13/756 using a signal generator for modifying the reflectivity of the reflector G01S13/758 takes precedence
• CPC Class Codes: G01S 13/765 with exchange of information between interrogator and responder
• CPC Class Codes: G01S 13/767 Responders; Transponders teaching or practice apparatus for gun-aiming or gun-laying using reflecting targets or active targets F41G3/26
• CPC Class Codes: G01S 13/78 discriminating between different kinds of targets, e.g. IFF-radar, i.e. identification of friend or foe G01S13/75, G01S13/79 take precedence
• CPC Class Codes: G01S 13/91 for traffic control G01S13/93 takes precedence
• CPC Class Codes: G06K 19/0705 the battery being connected to a power saving arrangement
• CPC Class Codes: G06K 19/0723 the record carrier comprising an arrangement for non-contact communication, e.g. wireless communication circuits on transponder cards, non-contact smart cards or RFIDs
• 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
• CPC Class Codes: G07B 15/063 using wireless information transmission between the vehicle and a fixed station identification of vehicles G08G
• CPC Class Codes: G07C 5/008 communicating information to a remotely located station transmission systems for measured values G08C
• CPC Class Codes: G08G 1/017 identifying vehicles G08G1/015, G08G1/054 take precedence

Abstract

A method and system is provided for communicating permanent or semi-permanent information to a transponder (14) from an interrogator (12), preferably operated by a toll agency or other authorized entity. This permanent or semi-permanent information is communicated by means of special instructions valid only during a special mode or maintenance mode which is entered by transmitting a special access code to the transponder (14) from the authorized interrogator (12). The transponder (14) will preferably acknowledge to the authorized interrogator (12) that it is, in fact, operating in the maintenance mode so the interrogator (12) can transmit the special instructions in confidence.

Claims

1. A method of accessing restricted addresses within a transponder, the method comprising the steps of sending an access code from said interrogator to said transponder, said access code enabling access to pre-determined addresses within the transponder'"'"'s memory, thereby entering a transponder maintenance mode;

and transmitting an interrogation message comprising a special instruction from said interrogator to said transponder, said special instruction valid only during said maintenance mode.

2. The method of claim 1 and further comprising the step of providing a maintenance mode acknowledgement signal from said transponder to said interrogator, said maintenance mode acknowledgement signal confirming to said interrogator that said transponder is in maintenance mode.

3. The method of claim 1 and further comprising the step of sending a response message from said transponder to said interrogator in response to said special instruction therefrom.

4. The method of claim 3 wherein said special instruction specifies that said transponder is to transmit the contents of selected transponder memory blocks in said response message.

5. The method of claim 1 wherein said special instruction is a test instruction that instructs the transponder to perform a test routine.

6. The method of claim 5 wherein said transponder in response to said test instruction loads a register with test data, increments the register, and transmits the new contents of the register in said response message.

7. The method of claim 3 wherein said special instruction specifies that said transponder transmit contents of its receive buffer in said response message.

8. The method of claim 1 and further comprising the step of disabling the maintenance mode upon the expiration of a maintenance mode timer.

9. The method of claim 1 and further comprising the step of disabling the maintenance mode upon the transmission of a new agency code to said transponder.

10. A method of testing a transponder, the method comprising the steps of sending an access code from said interrogator to said transponder, said access code enabling said transponder to perform a test routine wherein said transponder in response to a test instruction loads a register with test data, increments the register, and transmits the new contents of the register in a response message.

11. A recognition system having an interrogator that is selectively operable to transmit first signals, wherein said first signals include an access code, and a transponder operable to receive said first signals including said access code and to perform test operations upon receipt of said access code, said test operations not normally available to be performed without receipt of said access code, said recognition system comprising:

a) a transponder receiver, said transponder receiver operable to receive first signals including said access code and, following said access code, a test instruction from said interrogator;

b) a transponder controller within said transponder, said transponder controller operable to receive said access code, to compare said access code to a security code stored in said transponder, and should said access code be a pre-determined relationship to said security code, to receive said test instruction, said transponder controller further operable to perform otherwise unpermitted actions in response to said special instructions.

12. The system of claim 11 and further comprising a register, and wherein said otherwise unpermitted actions include a test routine wherein said transponder controller loads said register with test data, increments the register, and transmits the new contents of the register in a response message to said interrogator.