Extended command, Response – ACS AET63 BioTRUSTKey User Manual
Page 9

6.1.2.
Extended Command
A command consists of six protocol bytes and a variable number of data bytes and has the following
structure:
Byte
1
2
3
4
5
6 ... N+5
(N>0)
N+6
Header
Instruction
Data Length = N
Data
Checksum
FF
H
Data
Length
N
Header
01
H
to indicate the start of a standard command.
02
H
to indicate the start of an encrypted command (support from firmware 0.67
onwards, only used in PTVerifySC
(*)
and PTVerifySCAll
(*)
)
Instruction
The instruction code of the command to be carried out by the AET63.
Data Length
Number of subsequent data bytes, and is encoded in 3 bytes. The first byte is FF
H
.
The second byte and the third byte represent data length N.
Data
Data contents of the command.
For a READ command, for example, the data bytes would specify the start address
and the number of bytes to be read. For a WRITE command, the data bytes would
specify the start address and the data to be written to the card.
The data bytes can represent values to be written to a card and/or command
parameters such as an address, a counter, etc.
Checksum
The checksum is computed by XORing all command bytes including header,
instruction, data length and all data bytes.
Note (*) :
Please refer to “BioTRUSTKey API Manual.doc” for the descriptions of PTVerifySC
and PTVerifySCAll.
6.2. Response
The response from the AET63 to any command depends on whether the command has been
received by the reader without error (e.g., checksum error).
6.2.1.
No Transmission Error with Normal Response (Length < 255 bytes)
The response by the AET63 to a correctly received command consists of three protocol bytes, two
status bytes and a variable number of data bytes and has the following structure:
Byte
1
2
3
4
5 ... N+4
(0 N+5 Header SW1 SW2 Data length = N Data Checksum Header 01 H to indicate the start of the normal response. 02 H to indicate the start of an encrypted response (support from firmware 0.67 onwards, only used in PTVerifySC (*) and PTVerifySCAll (*) ) SW1 Indicates the command execution status: 90 H = command successfully executed 60 H = error in command data; command cannot be executed Document Title Here Document Title Here Document Title Here AET63 Reference Manual Version 2.2 Page 9 of 26 www.acs.com.hk