4
RFID
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sector 1
block 0
data block
4
block 1
data block
5
block 2
data block
6
block 3
Password A-access control-password B
control block
7
……
……
……
……
sector 0
block 0
data block
60
block 1
data block
61
block 2
data block
62
block 3
Password A-access control-password B
control block
63
Each sector has a set of independent password and access control which are put in the last block of each
sector, and the block is also known as sector trailer, that is Block 3 in each sector. Sector 0, block 0 (namely
absolute address 0) of S50 is used to store the vendor code, which has been solidified and can ’
t be changed,
and the card serial number is stored here. In addition to the manufacturer and the control block, the rest of
the cards are data blocks, which can be used to store data. Data block can be used for two kinds of applications:
(1) used as general data storage and can be operated for reading and writing.
(2) used as data value, and can be operated for initializing the value, adding value, subtracting and reading
the value.
The sector trailer block in each sector is the control block, including a 6-byte password A, 4-byte access
control and 6-byte password B. For example, the control block of a brand new card is as follows:
A0 A1 A2 A3 A4 A5
FF 07 80 69
B0 B1 B2 B3 B4 B5
password A
access control
password B
The default password of a brand new card is generally A0A1A2A3A4A5 for password A, B0B1B2B3B4B5 for
password B, or both the password A and password B are 6 FF. Access control is used to set the access
conditions for each block (including the control block itself) in a sector.
Blocks of S50 are divided into data blocks and control blocks. There are four operations, "read", "write", "add
value", "subtract value (including transmission and storage)" for data blocks, and there are two operations,
"read" and "write" for control blocks.
For more details about how to set data blocks and control blocks, please refer to Datasheet.
By default, after verifying password A or password B, we can do reading or writing operation to data blocks.
And after verifying password A, we can do reading or writing operation to control blocks. But password A can
never be read. If you choose to verify password A and then you forget the password A, the block will never
be able to read again. It is highly recommended that beginners should not try to change the contents of
control blocks.
