User's Manual

ACR122L-ACS Design Specification
Version 0.03 19/05/2010
Page
11
of
50
ACR122L
-
ACS
3) Activate a SAM (Incorrect Checksum, RDR)
HOST RDR
1. HOST sends a frame

02 62 00 00 00 00 00 01 01 00 00
[Checksum] 03
2. RDR sends back a
positive status frame
immediately
02 00 00 03 (positive status frame)

.. After some processing delay...
3. RDR sends back the
response (corrupted) of
the command
4. HOST sends a NAK
frame to get the
response again.
5. RDR sends back the
response of the command

02 80 0D 00 00 00 00 01 00 00 00 3B 2A 00
80 65 24 B0 00 02 00 82 90 00 [Incorrect
Checksum] 03
02 00 00 00 00 00 00 00 00 00 00 00 03
(NAK)
02 80 0D 00 00 00 00 01 00 00 00 3B 2A 00
80 65 24 B0 00 02 00 82 90 00 [Checksum]
03


Remarks:
If the frame sent by the HOST is correctly received by the RDR, a positive status frame = {02 00 00
03} will be sent to the HOST immediately to inform the HOST the frame is correctly received. The
HOST has to wait for the response of the command. The RDR will not receive any more frames while
the command is being processed.
In case of errors, a negative status frame will be sent to the HOST to indicate the frame is either
corrupted or wrong formatted.
- CheckSum Error Frame = {02 FF FF 03}
- Length Error Frame = {02 FE FE 03}. The length “dDwLength” is greater than 0x0105 bytes.
- ETX Error Frame = {02 FD FD 03}. The last byte is not equal to ETX “0x03”.
- TimeOut Error Frame = {02 FC FC 03}. Not Complete Package Received.
The NAK Frame is only used by the HOST to get the last response.
{02 00 00 00 00 00 00 00 00 00 00 00 03} // 11 zeros