The 770, and I think the 1100, have at least two accessory plugs that are tied to switches in the controller. One is labeled/designed for the computer and the other for coolant. For power off I simply exit out of PP until it tells me it's safe to turn off the computer, then I reach over to the control panel on the controller and flip the computer switch off. Next time I return to the mill I flip the computer switch on and PP powers up.

A little surprised the 440 doesn't work this way.