Method for detecting that contactless CPU card leaves radio-frequency field

• US 9,754,142 B2
• Filed: 12/21/2012
• Issued: 09/05/2017
• Est. Priority Date: 05/30/2012
• Status: Active Grant

• Current Assignee: Feitian Technologies Company Limited
• Original Assignee: Feitian Technologies Company Limited
• Inventors: Lu, Zhou, Yu, Huazhang
• Primary Examiner(s): YANG, JAMES J
• Application Number:
  US14/376,864
• Publication Number:
  US 20150091699A1
• Time in Patent Office: 1,719 Days
• CPC Class Codes: G06K 7/10128 the step consisting of detection of the presence of one or more record carriers in the vicinity of the interrogation device
• CPC Class Codes: G06K 7/10366 the interrogation device being adapted for miscellaneous applications

Abstract

A method for detecting that a contactless CPU card leaves a radio-frequency field relates to the field of smart cards. The method comprises: receiving and judging whether a valid instruction sent by an upper computer is received, and conducting a corresponding operation according to the received instruction; as a notification card search instruction, conducting a card search operation, and judging whether returned information is received; obtaining card number information about a contactless card according to the returned information; as an APDU instruction, sending A data to the card in accordance with a designated format, judging whether a response is received, and sending the operation result to the upper computer; as an extension instruction, executing a corresponding operation, and sending the operation result to the upper computer; when a valid instruction is not received, judging the mark of the card in the radio-frequency field, and if the card is in the radio-frequency field, conducting a card detection operation, and sending the operation result to the upper computer; and if the card is not in the radio-frequency field, conducting a card search operation. The present invention can detect the problem that a CPU card leaves a radio-frequency field in real time.

Claims

1. A method for detecting whether a contactless CPU card has left a radio frequency field comprising the steps of:

Step a, a card reader is switched to an interruption enabling condition;

Step b, the card reader receives an instruction sent by a master computer and determines whether the card reader received a valid instruction, if yes, determining a type of the valid instruction, if the type is an instruction on informing to seek a card, go to Step c;

if the type is an APDU instruction, go to Step d;

if the type is an extension instruction, go to Step e;

otherwise, go to Step f;

Step c, the card reader switches off the interruption enabling condition, sends a card seeking instruction to the card and determines whether the card reader received a card seeking response returned by the card, if yes, setting a flag in the card to a radio frequency field and switching on the interruption enabling condition, go to Step f;

otherwise, resetting the flag in the card to the radio frequency field and switching on the interruption enabling condition, go to Step f;

Step d, the card reader switches off the interruption enabling condition, sends the APDU instruction to the card and determines whether the card reader received a response returned by the card, if yes, setting the flag in the card to the radio frequency field, sending the received response to the master computer via a USB interrupting channel and switching on the interruption enabling condition, then go to Step f;

otherwise, resetting the flag of the card in the radio frequency field and switching on the interruption enabling condition, go to Step f;

Step e, the card reader switches off the interruption enabling condition, performs an operation according to the extension instruction, sends an operation result to the master computer via the USB interrupting channel and switches on the interruption enabling condition, go to Step f;

Step f, the card reader determines whether the flag of the card in the radio frequency field is set, if yes, sending a response that the card is in the radio frequency field to the master computer via the USB interrupting channel, then go back to Step a;

otherwise, sending the response that the card has left the radio frequency field to the master computer via the USB interrupting channel, then go back to Step a;

when the card reader receives a triggering of the interrupting, entering a regular interrupting process, comprising

Step g, the card reader switching off the interruption enabling condition and clearing any interrupting flag;

Step h, the card reader determines whether the flag of the card in the radio frequency field is set, if yes, go to Step i;

otherwise, sending the card seeking instruction to the card and determining whether a card seeking response is returned by the card, if yes, go to Step I;

otherwise, go to Step m;

Step i, the card reader sends a detecting instruction to the card and determines whether the card reader received a detecting response returned by the card, if yes, storing the detecting response and go to Step I;

otherwise, go to Step m;

Step l, the card reader switching on the interruption enabling condition, exiting the interrupting process; and

Step m, the card reader resetting the flag of the card in the radio frequency field, switching on the interruption enabling condition, and exiting the regular interrupting process.

2. The method of claim 1, wherein Step c further comprises

Step c11, the card reader switching off the interruption enabling condition, sending a first requesting instruction to the card, determining whether the card reader receives a first response returned by the card, if yes, go to Step c12;

otherwise, closing the radio frequency field, waiting for automatically opening the radio frequency field in a predetermined time, resetting the flag of the card in the radio frequency field and switching on the interruption enabling condition, then go to Step f;

Step c12, the card reader sends a second requesting instruction containing 0x93 and 0x20 to the card and obtains a first confirming information returned by the card;

Step c13, the card reader obtaining a first data according to a first confirming information and a fixed data and determining whether the first data is 0x00, if yes, a cascade level of the card is 1, the card number information is stored in buffer, then go to Step c18;

otherwise, go to Step c14;

Step c14, the card reader sends a third requesting instruction containing 0x95 and 0x20 to the card and obtains a second confirming information returned by the card;

Step c15, the card reader obtains a second data according to the second confirming information and the fixed data and determining whether the second data is 0x00, if yes, a cascade level of the card is 2 and the card number information is stored in the buffer, then go to Step c18;

otherwise, go to Step c16;

Step c16, the card reader sends a fourth requesting instruction containing 0x97 and 0x20 to the card and obtains a third confirming information;

Step c17, the card reader obtains a third data according to the third confirming information and the fixed data and determining whether the third data is 0x00, if yes, the cascade level of the card is 3 and the card number information is stored in the buffer, go to Step c18;

otherwise, closing the radio frequency field, waiting for automatically opening the radio frequency field in a predetermined time, resetting the flag of the card in the radio frequency field and switching on the interruption enabling condition, go to Step f;

Step c18, the card reader sends a request selecting and answering instruction to the card and determines whether the card reader received a selecting and answering response returned by the card, if yes, go to Step c19;

otherwise, resetting the flag of the card in the radio frequency field and switching on the interruption enabling condition;

then go to Step f; and

Step c19, the card reader setting the flag of the card in the radio frequency field and sending the selecting and answering response to the master computer via the USB interrupting channel and switching on the interruption enabling condition, then go to Step f.

3. The method of claim 1, wherein Step c further comprises

Step c21, the card reader switches off the interruption enabling condition, sends a fifth requesting instruction to the card and determines whether the card reader received a fifth response returned by the card, if yes, go to Step c22, otherwise, closing the radio frequency field and waiting for automatically opening the radio frequency field, resetting the flag of the card in the radio frequency field and switching on the interruption enabling condition;

then go to Step f;

Step c22, the card reader sends a request selecting and answering instruction to the card and determines whether the card reader received a selecting and answering response returned by the card, if yes, go to Step c23;

otherwise, resetting the flag of the card in the radio frequency field and switching on the interruption enabling condition;

then go to Step f; and

Step c23, the card reader setting the flag of the card in the radio frequency field, sending the selecting and answering response to the master computer and switching on the interruption enabling condition, then go to Step f.

4. The method of claim 1, wherein if no valid instruction is received in Step b, waiting for the receiving instruction;

Steps c to f, Steps l to m are replaced with Steps c′

to e′ and

Steps l′

to m′

, respectively;

Step c′

, the card reader switches off the interruption enabling condition and sends a card seeking instruction to the card and determines whether a card seeking response is returned by the card, if yes, setting the flag of the card in the radio frequency field and sending a response that the card is in the radio frequency field to the master computer via the USB interrupting channel;

then go back to Step a;

otherwise, resetting the flag of the card in the radio frequency field and sending a response that the card has left the radio frequency field to the master computer via the USB interrupting channel, then go back to Step a;

Step d′

, the card reader switches off the interruption enabling condition, sends the APDU instruction to the card and determining whether the card reader received a response returned by the card, if yes, setting the flag of the card in the radio frequency field and sending the received response and the response that the card is in the radio frequency field to the master computer via the USB interrupting channel, go back to Step a;

otherwise, resetting the flag of the card in the radio frequency field and sending the response that the card is in the radio frequency field to the master computer via the USB interrupting channel, go back to Step a;

Step e′

, the card reader switching off the interruption enabling condition, performing operation according to the extension instruction and sending the operation result to the master computer via the USB interrupting channel, then go back to Step a;

Step l′

, the card reader setting the flag of the card in the radio frequency field, sending the response that the card is in the radio frequency field to the master computer via the USB interrupting channel, switching on the interruption enabling condition and exiting the interrupting process; and

Step m′

, the card reader resetting the flag of the card in the radio frequency field, sending the response that the card leaves the radio frequency field to the master computer via the USB interrupting channel, switching on interruption enabling condition and exiting the regular interrupting process.

5. The method of claim 4, wherein Step c′

further comprises

Step c′

11, the card reader switching off the interruption enabling condition, sending a first requesting instruction to the card and determining whether the card reader received a first response returned by the card, if yes, go to Step c′

12;

otherwise, closing radio frequency field, waiting for automatically opening the radio frequency field in a predetermined time, resetting the flag of the card in the radio frequency field and sending the response that the card has left the radio frequency field to the master computer via the USB interrupting channel, go back to Step a;

Step c′

12, the card reader sending a second requesting instruction containing 0x93 and 0x20 to the card and obtaining a first confirming information returned from the card;

Step c′

13, the card reader obtaining a first data according to the first confirming information and the fixed data and determining whether the first data is 0x00, if yes, a cascade level of the card is 1 and storing the card number information is stored in buffer, then go to Step C′

18;

otherwise, go to Step c′

14;

Step c′

14, the card reader sending a third requesting instruction containing 0x95 and 0x20 to the card and obtaining a second confirming information returned by the card;

Step c′

15, the card reader obtaining a second data according to the second confirming information and the fixed data and determining whether the second data is 0x00, if yes, a cascade level of the card is 2 and the card number information is stored in the buffer, then go to Step c′

18;

otherwise, go to Step c′

16;

Step c′

16, the card reader sending a fourth requesting instruction containing 0x97 and 0x20 to the card and obtaining a third confirming information;

Step c′

17, the card reader obtaining a third data according to the third confirming information and the fixed data and determining whether the third data is 0x00, if yes, a cascade level of the card is 3 and the card number information is stored in buffer, then go to Step c′

18;

otherwise, closing the radio frequency field, waiting for automatically opening the radio frequency field in a predetermined time, restoring the flag of the card in the radio frequency field and sending the response that the card has left the radio frequency field to the master computer via the USB interrupting channel, then go back to Step a;

Step c′

18, the card reader sending a request selecting and answering instruction to the card and determining whether the card reader receives a selecting and answering response returned by the card, if yes, go to Step c′

19;

otherwise, resetting the flag of the card in the radio frequency field and sending the response that the card leaves the radio frequency field to the master computer via the USB interrupting channel, then go back to Step a; and

Step c′

19, the card reader setting the flag of the card in the radio frequency field and sending the selecting and answering response and the response that the card is in the radio frequency field to the master computer via the USB interrupting channel;

then go back to Step a.

6. The method of claim 4, wherein Step c′

further comprises

Step c′

21, the card reader switching off the interruption enabling condition and sending a fifth requesting instruction to the card and determining whether the card reader receives a fifth response returned from the card, if yes, go to Step c′

22;

otherwise, closing radio frequency field, waiting for automatically opening on the radio frequency field in a predetermined time, resetting the flag of the card in the radio frequency field and sending the response that the card leaves the radio frequency field to the master computer via the USB interrupting channel, then go back to Step a; and

Step c′

22, the card reader sends a request selecting and answering instruction to the card and determines whether the card reader received the selecting and answering response returned by the card, if yes, go to Step c′

23;

otherwise, resetting the flag of the card in the radio frequency field and sending the response that the card leaves the radio frequency field to the master computer via the USB interrupting channel;

go back to Step a.

7. The method of claim 1, wherein

sending the response that the card is in the radio frequency field to the master computer via the USB interrupting channel specifically comprises

determining whether a recorded card status is that the card is in the radio frequency field, if yes, go back to Step a, otherwise, updating the recorded card status to be that the card is in the radio frequency field, go back to Step a;

and

sending a response that the card has left the radio frequency field to the master computer via the USB interrupting channel further comprises

determining whether a recorded card status is that the card has left the radio frequency field, if yes, go back to Step a;

otherwise, updating the recorded card status to be that the card leaves the radio frequency field;

go back to Step a.

8. The method of claim 1, wherein determining whether the instruction is a valid instruction further comprises

the card reader receiving an instruction sent from a buffer via interrupting;

if a first byte of the instruction is identical to a predetermined character, the valid instruction is received;

otherwise, no valid instruction is received.

9. The method of claim 1, wherein the card reader sending a detecting instruction to the card further comprises

if it is the first time that the card reader sends the detecting instruction, the card reader sends a first predetermined character to the card;

while

if it is not the first time that the card sends the detecting instruction, the card reader determines the detecting instruction to be sent according to the detecting response, if the value of a last bit of the detecting response is 0, the card reader sends a first predetermined character string to the card;

if the value of the last bit of the detecting response is 1, the card reader sending a second predetermined character string to the card.

10. The method of claim 9, wherein determining whether the card reader successfully receives the detecting response returned by the card further comprises

if the detecting instruction is a first predetermined character string, the card reader determines whether the response returned by the card is a first detecting response, if yes, successfully receiving the detecting response returned by the card and storing the response;

if no, unsuccessfully receiving the detecting response returned by the card;

while

if the detecting instruction is a second predetermined character string, the card reader determines whether the response returned by the card is a second detecting response, if yes, successfully receiving the detecting response returned by the card and storing the response;

if no, unsuccessfully receiving the detecting response returned by the card.