Fixture 4 would be set to DMX address:
16 dipswitch number 5 on.
You can include you fog machine anywhere in this chain
We recommend you to read manuals for your DMX fixture and controller in full. Some controllers tell you
what each fixture address needs to be, and some lights need other settings changed before they will work.
When setting your DMX address, you must ensure fixtures don’t overlap from one to the next.
You can set 2 fixtures to the same address, and as long as they are the same fixture (i.e. same channel layout)
then they will then do the same as each other.