Bus systems - wiring, planning, etc.?

But if the bus system does not have to be star-shaped, then my statement is of course wrong.

I still don't understand why you think of a star at all when it comes to a bus. Bus and star do not exclude each other, but the core of a bus is the broadcast, and that is more the domain of the common rail. That's why your unusual statement really made me very curious for an explanation.

I had probably added to my post when you had already replied. It was mentioned here in the thread (see my previous post) and my web search also repeatedly came up with star-shaped structures.
That’s why I thought that with KNX the structure always had to be star-shaped and that was from my point of view very complicated and time-consuming

I understood it so that only one actuator is allowed per line and therefore a star-shaped structure is necessary. And I found exactly that to be extremely complex.

No, KNX is the technology of choice. In principle, you can lay the bus however you like. Only closed loops are not "allowed" because ghost telegrams occur, so better not. This is what an installation can look like:

I understood it so that only one actuator is allowed per line and therefore a star-shaped structure is necessary. And I found exactly that to be extremely complex.

Yes, that's simply not the case. I wrote star wiring and bus wiring. The latter is basically free. Every switchable channel (if to be switched from the distribution board) must then be wired in a star, i.e. NYM cable, not bus cable. If you want to rely on decentralized actuators or retrofit later, you can also dispense with star wiring here and connect everything in series. Bus and NYM. You encounter star wiring when searching the internet because it is the favored method for a new installation on the NYM side, and so it is done that way. The bus is generally always wired as a mix.

"Bus" and "star" often come from people who have once looked at Loxone. With the green island solution, that's how it was done (I know, there is Loxone Tree, but it still remains Loxone). With KNX, you can wire however you want, as long as it is not a closed loop and the maximum cable lengths per line and between participants are not exceeded. However, this rarely happens in a single-family house. At this point, I would also recommend some basic reading on the topic of KNX or bus systems in general...

I had probably supplemented my post when you had already replied.

At least nothing explanatory emerged from the additions – when I saw it, it already said (as it does currently)

The bus system has a star-shaped structure. Thus, only one terminal per connection.

I hoped you would enlighten me either on how you revolutionized network topologies or where you concocted a mistaken assumption. A bus is actually a network topology in its own right, which competes without overlap with the star; and sockets so closely adjacent that they can be perceived as a double socket are not excluded. On the one hand, laypeople easily perceive folded buses as stars; and on the other hand, "bus" has become an established term for communication in systems that are actually not buses, but only have essential parts of their properties: saving wires, enabling tap connections at relatively many points, broadcast (also with selective call).

Yes, you can see that you know a lot, but just don’t know "small" details. I simply knew the term bus as a transmission path between two components. And that is formally wrong. Until now, I was not aware that a bus is a topology. That’s why I always thought of the "Bus" simply as the "data line." Learned something new again.