User's Manual

Product Manual - RFID Reader UF70 Certum 41
Chapter 7
Operation
7.2.2 Package contents
General remarks:
Each package includes a package header (three characters), a message (two or
more characters) and the end of the package (five characters).
Package header The header includes the start character (one character) and the package length
(two characters)
2 starting characters and 4 length bytes are sent in the extended ASCII protocol.
Start Start character (ASCII character ´S´)
Length 1 High byte package length (hexadecimal) –
ASCII characters ´0´..´F´
Length 2 Low byte package length (hexadecimal) –
ASCII characters ´0´..´F´
Extended ASCII format:
Start 1 First start character (ASCII character 'S')
Start 2 Second start character (ASCII character 'X') for marking
the extended ASCII protocol
Length 1 High byte package length (hexadecimal) -
ASCII characters ´0´..´F´
Length 2 Byte package length (hexadecimal) -
ASCII characters ´0´..´F´
Length 3 Byte package length (hexadecimal) -
ASCII characters ´0´..´F´
Length 4 Low byte package length
(hexadecimal) - ASCII characters ´0´..´F´
The message length describes the number of characters of a message.
Package header Message End of package
Package header
Start Length 1 Length 2
Package header
Start 1 Start 2 Length 1 Length 2 Length 3 Length 4
nbb