i recently bought a house with the Sony Cav-M1000ES and CAV-CVS12ES installed. I'm trying to work with what I have. Can't afford to swap these out. Would like to manage the zones with a custom iphone app via Global Cache. Looks like the only why to "talk" to the M1000ES is via an rs232 port. I would appreciate getting all the "codes", esp turning on/off a zone, input selection, volume control. And would love to hear how you interfaced to Alexa.

Thanks,
Bill
bhoma(at)maine (dot) rr (dot) com