The DMX address tool is a quite easy/self explanatory functionality of QLC+ introduced in version 4.3.2.
It helps you to calculate your fixtures addresses quickly in a visual way.
A representation of a common 10way DIP switch is displayed and you can select the background color, the horizontal and vertical orientation, so that the DIP switch is displayed exactly as you would see it on your fixture.
Note that for many fixtures, switch 10 is used to enable or disable the DMX input. If your product manual says it has to be 'on' to enable the DMX input, then remember to do it even if QLC+ has it set to OFF.