I known you can control the rig with the CI-V interface, but my question is: Once the rig goes to sleep (inactivity timeout) can it be turned back on without having to use the power button on the front?
The inactivity timeout is controlled by the auto-power-off menu setting where you can designate the number of minutes, such as 30 minutes, for the radio to be switched off.
But, this is tantamount to turning the radio off just as if you had pushed (and, held) the power button on the front panel. It is not some "sleep mode" where functions are still active, such as listening on the CI-V port.
I own an Icom IC-706MkIIG and use it as a mobile rig but I used to have it in my home shack. I have a habit of keeping the radios on all the time. Sometimes, not turning them off for weeks, maybe even months, although I never kept track of when I turned power off or how frequently.
Therefore, why not disable the auto-off feature and then leave the radio on power all the time. In idle mode, it is not consuming very much power and may be a reasonable alternative unless you are on some kind of battery backup.
It sounds like you may not have the user guide, it is easily found at the Icom America web site, here is a link: http://www.icomamerica.com/en/downloads/default.aspx?category=38