Tablet daemon
The tablet daemon runs in the background and does the ground work. Detecting the tablet and set it up with the selected profiles. If the daemon is not running the module and the plasma applet cannot work properly and the tablet cannot be used with the profiles.

Tablet detection
The detection of the tablet device is done in several ways. Solid is used in the first step and does the hotplug support. If Solid fails the next steps are xsetwacom list dev, lsusb and xinput --list.
Should none of the commands above return the name of the tablet, it is not supported and cannot be used by this module.

Detection problems
If the tablet is not detected check the Wacom driver or DIGImend driver page if your tablet is supported. Furthermore check via lsusb if you can find your tablet.
If udev does not handle the detection add the tablet to your /etc/X11/xorg.conf.d/50-tablet.conf file (create it if it does not exist) and restart the x-server.
In case of a serial device (Tablet PC and such) check if xinput --list lists your input devices (Stylus/Eraser/Pad). Should they be listed take a look at the internal tablet device id via xsetwacom get "Name of your pad or stylus" TabletID. If an id is returned please mail all the necessary information to the author.
Hotplug support is only available if the tablet is found via Solid and its notification API.
Solid checks if the value for the entry input.x11_options.Type is pen, stylus, eraser or cursor or if the value for the entry input.x11_driver is wacom.
Please mail the author if your tablet is detected by Solid but with other values to enhance the tablet support.