ACR122L – Communication Protocol
Version 1.03
www.acs.com.hk
Page 48 of 57
Step 3. Write (Mifare compatible Write) the content of Page
04
with
the data “AA BB CC DD”
HOST -> 02 6F 1A 00 00 00 00 01 00 00 00
HOST -> FF 00 00 00 15 D4 40
01
A0
04
AA BB CC DD
00 00 00 00 00 00 00 00 00 00 00 00
[Checksum] 03
RDR -> 02 00 00 03 (Waiting the Tag)
RDR -> 02 80 05 00 00 00 00 01 01 00 00
RDR -> D5 41 [00] 90 00 [Checksum] 03
Note:
This command is implemented to accommodate the established Mifare 1K/4K infrastructure.
We have to assemble the data into a 16 bytes frame. The first 4 bytes are for data, the rest of the
bytes (12 ZEROS) are for padding. Only the page 4 (4 bytes) is updated even through 16 byte are
sent to the reader.
Step 4. Read the content of Page
04
again.
HOST -> 02 6F 0A 00 00 00 00 01 00 00 00
HOST -> FF 00 00 00 05 D4 40
01
30
04
[Checksum] 03
RDR -> 02 00 00 03 (Waiting the Tag)
RDR -> 02 80 15 00 00 00 00 01 01 00 00
RDR -> D5 41 [00]
AA BB CC DD 05 06 07 08 09 10 11 12 13 14 15 16
90 00 [Checksum] 03
In which, Block Data =
AA BB CC DD 05 06 07 08 09 10 11 12 13 14 15 16
Note:
Only the page 4 is updated. Pages 5, 6 and 7 remain the same.
Step 5. Halt the tag (optional).
HOST -> 02 6F 08 00 00 00 00 01 00 00 00
HOST -> FF 00 00 00 03 D4 44
01
[Checksum] 03
RDR -> 02 00 00 03 (Waiting the Tag)
RDR -> 02 80 05 00 00 00 00 01 01 00 00
RDR -> D5 45 [00] 90 00 [Checksum] 03
Note:
Please refer to the Mifare Ultralight specification for more detailed information.