Depends on your definition of simple. I did an article a good few years ago on a system which only needed 3 wires round the track (like a ring main but not quite) but had a processor in each signal. If that is of interest pm me you email and I'll send details. Anything which doesn't have at least some logic in each signal is likely to need a lot more wiring
Edited By duncan webster on 06/09/2023 15:19:45
Edited By duncan webster on 06/09/2023 15:20:24