Wiring Rules (CAT-5) reducing problems

Newbie, so bear with me! Thinking about Cbus for new house

Couple of questions on wiring with the CAT-5 pink cable.
I have looked at both introductory and training manuals and some things are still not clear.

Inputs, either switches, PIRS etc are wired in either a daisy chain or star formation. In daisy chain, each input, bar 'first' one, essentially has two cables into it, first from previous input and one to next input. Orange and blue wires from both cables are put in positive terminal with orange/white blue/white terminated in negative terminal only at first and last input, other I am assumming these are crimped at other input points.

Now, I'm sure above is completely wrong, but I dont think it hides fact that the system in daisy chain has single point failure. Do installers use any guidelines to reduce this, using loops of some sort to provide redundancy?

Given say four rooms with say two inputs in each (switch + PIR), are they normally daisy chained here and then all rooms placed in star formation at sinlge point before return to Cbus enclosure?

 

Wired C-Bus can be connected in daisy-chain as you suggest, but if you are concerned about a single point-of-failure, I would recommend that both ends of the daisy chain be taken back to a common position, probably where output units / power supplies, or similar are mounted (unless doing so will take you beyond the limit of 1km of cable total for a given network). While the loop could be completed, in my experience I have found that it is better to leave one end open so that in the event of a fault, a conscious decision can be made to either connect the other end or repair the fault.

If the loop is completed, you might have a wire break at some point (mechanical damage due to vermin), and not be aware until a second break occurs, then you have run out of options. If the loop is left incomplete, you have an opportunity to find and fix both the fault and its cause (install a python), but at the same time can get the system going again quickly.

A break is only one possible fault. The other fault is a short circuit, and the more cable that is connected in parallel, the worse the risk of a short circuit. You should aim at a point somewhere in the middle.

Don