HERMOS LFM 4x - Message Data; Packet End

Customer manual
LFM 4x Reader
RFID
WE GENERATE SOLUTIONS
HERMOS AG
Gartenstraße 19 • 95490 Mistelgau
Phone: +49 9279 991 - 0
E-mail: rfid@hermos.com
LFM 4x Reader Rev1.4
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Length 2 Byte packet length (ASCII character „0“-“F“)
Length 3 Byte packet length (ASCII character „0“-“F“)
Length 4 Low byte of the message length (ASCII character „0“-“F“)
Message data
The message contains a command character, a target or source address, the
number of the antenna port (head) and the actual message data.
The number of the antenna port is not required for all messages.
Message data
Command
Address
Data
Command The command is defined by an ASCII character. (See protocol
commands)
Address Target/source address (ASCII characters „0“, „1“, …) *
Data The definition of the message data depends on the protocol command.
* Depending on Factoryparameterset, the readers are addressed via the address
„0 ... 3“ or „1 ... 4“.
Packet end
The end of the packet contains an end character and a checksum consisting of 4
characters.
Packet end
End character
Checksum 1
Checksum 2
Checksum 3
Checksum 4
End character ASCII end character <CR> (hex 0x0D).
Checksum 1 High byte XOR logic of all data (packet header, data and end character).
(ASCII character „0“…“F“)
Checksum 2 Low byte XOR logic of all data (packet header, data and end character).
(ASCII character „0“…“F“)
Checksum 3 High byte addition of all data (packet header, data and end character).
(ASCII character „0“…“F“)
Checksum 4 Low byte addition of all data (packet header, data and end character).
(ASCII character „0“…“F“)