How to read user data of UHF RFID tag

Uhf RFID tags are generally divided into four areas:

【Reserve 】 Address: 0-3; Address: 0-1 Store the 32bit kill password (kill). The default value is 00 00 00 00.
2-3 Store the 32-bit Access password. The default value is 00 00 00 00.
When the local area is not encrypted or encrypted, the data in the area can be rewritten at will.

【EPC(EPC Area)】 Address: 2-7; Store the 96bit ID number, which is the area where the data that is normally read out by default by our device is stored. When the local area is not encrypted or encrypted, the data in the area can be rewritten at will.

【TID(TID area)】 Address: 0-5; Store a 48-bit globally unique and unalterable ID number.

【User(User area)】 Address: 0-31; Store 688-bit data. By default, each address is 00 00. If the area is not encrypted or encrypted, data in the area can be rewritten at will.

The above areas are explained with the Alien H9, a more commonly used tag chip, as an example. Different chips, the corresponding regional data and the actual role may be different

To read the USER area data, it is recommended that you first look at the EPC protocol, EPC several basic operations are read, write, lock, kill.
The protocol document is very detailed, in addition, if you are doing application development, to operate according to the API provided by the manufacturers, you need to read the API functions of the manufacturers.
If you are doing the underlying baseband development, you should be more familiar with the EPC protocol.