Thank you,

It's operating now and I am controlling it easily with IR - however, I want to do away with IR and use RS232 only.

You have given me "main room off" which works well. I need the following to get functional with RS232.

Main room on
Main room input
Main room mute
Zone 2 input
Zone 3 input

Explaining how you take the info from the Sony Amp/Rec RS232 Protocol document and end up with the hex command would be most helpful.

Thanks,
Chuck