Mifare Desfire EV1 Cyclic File

[narendc]

I have create a cyclic file with 10 records and each record is 32 bytes long. I am using ISO-IEC APPEND RECORD and everything works file except
I can add only 9 records. The 10th record overrides the first record. why is that I use 1 less record?
Is there a ISO-IEC 7816-4 command to record multiple records at a time using single commands?

Regards

---

+ 0  |  - 0

[narendc]

This is correction to above question. Is there a ISO/IEC 7816-4 command to read multiple records from either linear/cyclic file that MIFARE Desfire EV1 tag supports?

---

+ 0  |  - 0

[mifaresdk]

Hi Narendc,

As a recommendation from my side: you have full access to the DESFire with the native commands. For cyclic record files there are special commands:
CreateCyclicRecordFile(),
WriteRecord(),
ReadRecords(),
ClearRecordFile()
and
CommitTransaction(),
AbortTransaction().

Regards,
The TapLinx Team

---

+ 0  |  - 0

[TapLinx Support]

Hi Narendc,

You have to declare always one record more as you use it! The “majority record” is needed for the internal backup mechanism.

Please read page 84 of the functional data sheet: “In cyclic record files the maximum number of stored valid records is one less than the number of records specified in the CreateCyclicRecordFile command.”

Regards,
The TapLinx Team

---

+ 0  |  - 0

[narendc]

Excellent, thanks everyone. I understand Native commands are best but I have been asked to use ISO commands. I saw the documentation and it is indeed mentioned there. While reading my eyes probably missed that section. I got it, it is in page no 87 of 114.

cheers

---

+ 0  |  - 0

[TapLinx Support]

Hi Narendc,

With ISO commands you have limited possibilities. Anyway, if you use the ISO command APPEND RECORD or you use native commands, you have to leave one record for the update mechanism of the file system.

Regards,
The TapLinx Team

---

+ 0  |  - 0

[Author]

Posts