User's Manual

OPERATION 5
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Transponder Reader – CF-Card, Release 1.1
5 OPERATION
5.1 Protocol
5.1.1 Message Structure
All messages have the following structure:
Length Header Data Checksum
1 byte 2 bytes 1 or more bytes 2 bytes
Header
Command Action #
Length: Number of bytes of Header and Data
(without Length and Checksum).
Header: Consists of Command and Action #
Command: Defines the function of the message.
Action #: To distinguish the single messages the Action # will
be increased for each new message.
Data: The content depends of the message type.
Checksum: 2 bytes checksum over Length, Header and Data
(sum of byte values).