You may need to give Denon a call on this one. I looked around and didn't see any control modules. I also didn't see any third party control documentation on the Denon site. It might be there as I didn't look for very long. But, Denon usually has pretty good documentation on its stuff.
it is open source but you won't find a free AMX module for it. There is a module by Rocket GUI I think but if you want free you'll have to start writing and 250 hours later you'll realize it wasn't free. IMHO it makes no sense to write complicated AMX modules in this environment since you will not likely recoup your investment by the time that device is obsolete or you give up on AMX all together.
HEOS CLI commands are in the following general format: heos://command_group/command?attribute1=value1&attribute2=value2&...&at tributeN=valueN The command strings should be encoded using URL encoding. Command string delimiter is "\r\n".
Comments
http://www2.aerne.com/Public/dok-sw.nsf/0c6187bc750a16fcc1256e3c005a9740/9193bea412104506c1257dbd00298c78/$FILE/HEOS_CLI_ProtocolSpecification-Verion-1.3.pdf
HEOS CLI commands are in the following general format:
heos://command_group/command?attribute1=value1&attribute2=value2&...&at tributeN=valueN
The command strings should be encoded using URL encoding.
Command string delimiter is "\r\n".