A while back while surfing the net I came across Paul Barretts site.. Paul is a xAP user and I noticed he had documented a rs485 protocol for xAP devices..I contacted him and asked if he was interested in using a common protocol for xPL /xAP rs485 devices .This would mean any rs485 hardware developed by either protocol users could be used by either.... He was interested which was great news so we also invited Ian Bird and Neil Wrighton to assist us in formulating a standard rs485 protocol....
Some great progress was made on the protocol ,but unfortunately everyone got too busy with their own projects etc to further refine the protocol doc so I made a request from the guys to allow me to publish it on my site for others to view /comment....If anyone has any suggestions , enhancements please contact me on my email address and I will pass on the info to the other guys and update the doc if required...
The protocol name for the rs485 network is xAPL-NET...pronounced zapple net..

Proposed rs485 protocol Doc Word Format