Network UPS Tools Hardware compatibility list. Before you buy, take a look at the Acknowledgements. Be sure to also read the footnotes. For a list of user reported dumps of NUT supported devices, go visit the Devices Dumps Library. A daemon for controlling APC UPSesapcupsd 3. It also contains a workaround for an UPS firmware issue that causes killpower to execute repeatedly in a loop, resulting in the UPS continually cycling power. The precise list of affected models is unknown, but the Back UPS BR models are known to be afflicted and likely many other Back UPS USB models are as well. If you are utilizing apcupsd with a Back UPS over a USB interface, it is highly recommended to upgrade to this release. Please see the Release. Notes for a summary of changes in this release. A Change. Log is also available with a complete list of commits. Download apcupsd 3. Source. Windows. OS X.