So I just got a Russound CAA66 multizone controller. Looks interesting. The serial protocol is public, so I'm writing some code to interface my existing system with it. The docs say "19200 baud with 1 start bit, 1 stop bit, no parity, no flow control." I think this means "19200-8-N-1". The strange thing is, it seems to "see" my messages fine. But it's acks are supposed to start with 0xF0 and end with 0xF7. Instead, they start and end with 0x3F. Does this make any darn sense? The rest of the characters actually seem fine, just the start and end don't match. I suppose the most likely candidate is bad docs, because I don't see a transformation that makes both 0xF0 and 0xF7 into 0x3F and then suddenly resolves itself on the next byte.