Shut down Mac Server when APC 1400 battery is nearly empty

I'm running OS X Server on a Mac Mini. I'm powering the server via an APC 1400 (one of the older, beige ones). It has a serial connector, so I assume it could possibly interface with the Mac Mini via a serial to USB adapter. Is it possible to power down the OS X Server when the UPS batter is nearly depleted with my setup? Do I need to install APC software to get this to work? Will a serial to USB adapter do the job? Or is my APC backup unit too ancient to work with my Mac Mini in this scenario?