Header

The first part of the frame is a header field which is always present. The header occupies fields 1 - 6 for UART and 1 - 7 for radio commands in the examples.

1	2	3	4	5	6	6(or 7)
Length	ID Info	Command	GRP	ID	To ID	CRC

Type	Description
Length	The length of the message
ID Info	ID Info informs of the number of relays and a pointer of the active relay in radio communication. Set to 00 for UART command. See more about this in section Relaying.
Command	Instruction on what to do.
GRP	Active group number.
ID	From ID (Or ‘To ID’ when the command is a UART command)
ID TO	To ID (for Radio commands.)
CRC	CRC-8 on header