This will describe how to configure a APC UPS with Ubuntu
Installation
sudo apt-get install apcupsd apcupsd-cgi
Configuration
Update the apcupsd to set it to configured
sudo vi /etc/default/apcupsd
# ISCONFIGURED=no
ISCONFIGURED=yes
Now edit the configuration file
sudo vi /etc/apcupsd/apcupsd.conf
Change the cable type, and then the type and the device
# UPSCABLE smart
UPSCABLE usb
# UPSTYPE apcsmart
# DEVICE /dev/ttyS0
UPSTYPE usb
DEVICE
Testing
sudo apcupsd start
sudo apcaccess status