For some variety I occassionally install FreeBSD. However, I couldn’t find any UPS control software that fit my needs. So I studied the sources of various Linux centric UPS daemons such as genpowerd and powerd. TinyUPS Daemon is what I call the result of my efforts.
An Uninterruptible Power Supply is required. Any UPS supporting dumb signalling should work but it has only been tested with an APC Back-UPS and the cable shown.
/* * UPS Side Serial Port Side * 9 Pin Male 9 Pin Female * * Shutdown UPS 1 <---------------> 3 TX (high = kill power) * Line Fail 2 <---------------> 1 DCD (high = power fail) * Ground 4 <---------------> 5 GND * Low Battery 5 <----+----------> 6 DSR (low = low battery) * `---| |---> 4 DTR (cable power) */
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