Dear Chen,
I hope you are doing well.
Your TAG only supports ISO/IEC 15693-3.
Could you please confirm you are coding your commands under this standard?
On the ISO/IEC 15693-3 documentation you will find the command structures and codes.
For example, the command code for READ SINGLE BLOCK is 20h, and its structure is:
{SOF, Flags (1 byte), command code (1 byte), UID (8 bytes), block number (1 byte), CRC16 (2 bytes), EOF}
Here is the implementation I used:
First I request the inventory
[pTxBuffer=010000]
Then, I select my SL2S2602 card.
[pUid=D71C6E01080104E0 bUidLength=08 -> pTxBuffer=25]
Finally, I read block 00 from the User Memory, which contains 686F6C61.
[pTxBuffer=2000 -> ppData=686F6C61]
Could you please confirm that you are performing the inventory and TAG selection?
I hope this information helps. Please let us know if you have any doubts or concerns and we will be glad to assist you.
Best regards,
Javier