Here is my question: how do high end system manage to get a feedback from devices that only offer IR input (no RS 232 or anything else).
Do they use a proprietary hardware, or is it software based somehow?

I have seen demoes where the user can set the volume on a TV set, and does get a feedback on his iPhone, as it gives the volume level as a percentage of max.

The reason why I'm asking:
I currently use a Pronto TSU 7000, but would like to upgrade to have full 2 way capabilities. I like the iPhone as a device, and would like to base my next system on this.
Many high end supplyers (Crestron for instance), do provide iPhone interface.
There is a company called Commandfusion that has developped a software called iViewer to create an interface to operate Crestron and AMX with the iPhone.
I will not go for the Crestron solution (too expensive for me) but rather with Global Cache iTach.

Thanks

Olivier