It's possible to build a powerful catching station's systems, but it's also possible to charge circular
itself with this task. Then the only task for the station is loading and unloading trains. That's why circular stations look similar.
And they all work the same way. Train waits on in-line A until free platform appears. And then goes to it (using line-changer B and situation control depot I if neccessary).
The same way works the station for exit. Train will go from the station if any of out-lines L is free. If neccessary, line-changer K would be used.
The number of station's platforms depends on number of trains and number of carriages of the latter loaded or unloaded on the station.