I wish I could help you with this. Only piece of info I have (per
@limac92):
Case study:
For "XFG" insim sends [88, 70, 71, 0],
88 is ASCII "X",
70 is ASCII "F",
71 is ASCII "G".
For E-Chellenger (FA2989) insim sends bytes [137, 41, 250, 0],
but we cannot treat this values like ASCII characters because we'll get "‰)ú\0",
but,
137 is in HEX 89,
41 is in HEX 29,
250 is in HEX FA.
So I guess you would need to change each letter to its ASCII counterpart then to hex. Second part is easy-ish. No idea about first.
But I wouldn't count on mod stats from FM's airio. We have to clean every non-ascii entry in database every so often because they cause airio failing to launch after it's restarted.