The SXAO protocol is very simple and is given below :

All the protocol commands will be recognized (but not necessarily proceeded) by the microcontroller.

This is a fixed-width protocol, zero bytes being inserted at the end of commands depending on whether or not they include parameters.

This fixed width will not be respected by the microcontroller: as soon as a valid command is received, it will be able to know over how many bytes it spans, and will just listen to this number of bytes, ignoring the others until upon receipt of a new valid command.

Here is for the SX AO protocol.