This is how the components will be connected.

The one in the foreground is still in the making, the others are finished.
The Ethernet gateway connected to the DMX controller and that connected to a DMX hub and all supplied from a 12V power hub. This is how the system will be built .. all little building blocks with different functions and everything connected with straight cables.

This part of the network is working and all the boxes will get a shake and rattle test before they go into the van. I will only have very limited wiring to do at the van directly. I can do all cables in my lab and test them properly before they go into the van. This should make the build and commissioning reasonably easy. Such a concept needs lots of plugs and connectors and is not really feasible for mass production of the average caravan, but the again the average caravan would not need that many connectors anyway. All my connectors are screw type and/or waterproof high quality connectors to make sure everything stays in place no matter what and I am certain this will work well.