Power failure signal device/interface

I currently use a "dumb" HP UPS for my core, network and cameras. I haven't had any luck getting communication out of its serial port and from the online material I have read it may not have came installed with that comm. module.

To the point and question: For my old UPS or for any UPS not designed to communicate when it switches to battery back-up, what other methods have people used for safe shutdown timers or last minute events/log dumps?

Z-wave, Insteon and X-10 did not seem to have any this capability as I imagine most if not all of these networks fail when power is lost. 1-wire if I understand it enough from my reading the last few days could detect 0 amp draw on a line and be configured to activate an event from that (looking at energy saving devices that watch amp draw then report).

This isn't a huge concern as I have power dropped this machine from frustration more times that I candle to admit but if I can pull a power failure message from somewhere more backup options become available to me. Gasoline generators, pull power from the solar fueled cells (one of my other tinker projects) or at least time to remote in, check security feeds and power down.