==== APC UPS Devices ====

Install the required packages:

  apt install apcupsd apcupsd-cgi
  
Edit the conf file

  nano /etc/apcupsd/apcupsd.conf:

  UPSCABLE usb
  UPSTYPE usb
  #DEVICE /dev/ttyS0
  POLLTIME 60
  BATTERYLEVEL 10
  MINUTES 3

Restart the UPS monitoring service:

  systemctl restart apcupsd.service

Check /var/log/syslog for errors and check communication with:

  apcaccess
  
NOTE: Currently this package is old and produces constant errors in the events log. - it may be better to use NUT

==== Using NUT for UPS ====

Install the required packages:

  apt install nut
  
Edit the ups.conf file.

  nano /etc/nut/ups.conf
  
Add the following at the bottom of the file.

 [apc]
 driver = usbhid-ups
 port = auto
 #cable = 940-0095B
 desc = "Back-UPS BX750MI"
 #override.battery.charge.low = 50
 #onlinedischarge_calibration = set
 pollonly
 lbrb_log_delay_sec = 3
 lbrb_log_delay_without_calibrating

Edit /etc/nut/upsd.conf

  nano /etc/nut/upsd.conf
  
Uncomment and modify the following lines.

  MAXAGE 30
  LISTEN 127.0.0.1 3493
  MAXCONN 10
  
Edit the file  /etc/nut/upsd.users

  nano /etc/nut/upsd.users

Add the following to the end of the file.
  
  [upsuser]
  password=<secret>  <-- This can be anything (make up some secret)
  upsmon master
  
Edit /etc/nut/upsmon.conf

  nano /etc/nut/upsmon.conf

Uncomment and set the following lines...


  MONITOR apc@localhost 1 upsuser <secret> master
  NOTIFYCMD /etc/nut/notify-email
  SHUTDOWNCMD "/sbin/shutdown -P +0"
  DEADTIME 20
  NOTIFYFLAG ONLINE     SYSLOG+WALL+EXEC
  NOTIFYFLAG ONBATT     SYSLOG+WALL+EXEC
  NOTIFYFLAG LOWBATT    SYSLOG+WALL+EXEC
  NOTIFYFLAG FSD        SYSLOG+WALL+EXEC
  NOTIFYFLAG COMMOK     SYSLOG+WALL+EXEC
  NOTIFYFLAG COMMBAD    SYSLOG+WALL+EXEC
  NOTIFYFLAG SHUTDOWN   SYSLOG+WALL+EXEC
  NOTIFYFLAG REPLBATT   SYSLOG+WALL+EXEC
  NOTIFYFLAG NOCOMM     SYSLOG+WALL+EXEC
  NOTIFYFLAG NOPARENT   SYSLOG+WALL+EXEC

Now create a script to send email notifications /etc/nut/notify-email

  nano /etc/nut/notify-email
  
In /etc/nut/notify-email add:  (you will need to prefix the file with a bash shell)

<code>
#!/bin/s<remove>h characters (this line is messed due to wiki not allowing them)
SUBJECT="`hostname`: Power Event"
FROM_ADDR="root@<host>.net"
FROM_NAME="UPS"
TO="<recepient>"
echo "Subject: $SUBJECT\n\n$*" | sendmail -f "$FROM_ADDR" -F "$FROM_NAME" "$TO"
</code>

Set the necessary permissions:

<code>
chown root:nut ups.conf upsd.conf upsd.users upsmon.conf notify-email
chmod 0640 ups.conf upsd.conf upsd.users upsmon.conf
chmod 0750 notify-email
</code>

Change the following in /etc/nut/nut.conf:

  MODE=standalone

Restart the UPS monitoring service:

<code>
systemctl restart nut-server.service
systemctl restart nut-monitor.service
</code>

Check /var/log/syslog for errors and check communication with:

  upsc apc@localhost
  
(You may need to reboot before the USB is allowed to talk to the UPS).