Yamaha RX-A2030 IP Control

volume up = YamahaRemoteControl/ctrl?<YAMAHA_AV cmd="PUT"><Main_Zone><Volume><Lvl><Val>Up</Val><Exp></Exp><Unit></Unit></Lvl></Volume></Main_Zone></YAMAHA_AV>

volume down = YamahaRemoteControl/ctrl?<YAMAHA_AV cmd="PUT"><Main_Zone><Volume><Lvl><Val>Down</Val><Exp></Exp><Unit></Unit></Lvl></Volume></Main_Zone></YAMAHA_AV>

try this http://files.remotecentral.com/library/22-1/yamaha/index.html

http://ci.yamahaconnect.com/

Full control protocol docs are available at their CI site. The control is simple and very easy to write a module for.

I'd wager that if you write or call them they will hook you up. It is rare that I don't get some kind of response. It happens on occasion but most times their tech support just emails the docs out. In this business you cannot give up too easily.