Andi, the difference in the LUL implementation is the 'outer homes' are testing the occupancy of several track circuits within the platform length. Refer to the diagram at the TubePrune link I posted in the other thread - http://www.trainweb.org/tubeprune/signalling1.htm#Multi%20Home%20Signals
. They are also 2-aspect signals, each thus allowing a draw-up (usually at reduced speed) toward the next signal. Idea is to reduce run-in time as the train ahead gradually clears the platform.
A good example on the District is the EB slow road from Ealing Common to Acton Town. The first outer home (A) is speed sensing and clears when/if the train is at or below 20mph. The next two (B, C) clear as the train ahead clears the track sections covering about the first and second thirds of the platform. The final (the usual 'home') clears once the train ahead clears the platform and starter overlap. Thus the approaching train can safely close up on the train ahead and reduce its run-in time. TubePrune describes it with actual photos of the area here: http://www.trainweb.org/tubeprune/Speed%20Control%20Photos.htm
But they depend on reading the state of track sections ahead of the train (in the platform area), and not those normally associated with a section starting at the signal. From what I've read here about RS (and what MSTS does) is limit the 'block occupancy' test for a signal to its 'own block'. Thus my idea (as yet untested) of having fake hidden 'info type' signal objects (and their interactives) part ways along the platform that have a state defined by testing their block occupancy. Thus a real signal in rear of them could test these 'platform track circuit signals' for state and set their own state/aspect accordingly.
My hope with RS was that a signal actually tested a track circuit (default it's own immediately ahead) but could also test a circuit of specified ID ahead of itself. The current implementation (as with MSTS) appears to use what I think of as implied track circuits or blocks. As for the apparent RS implementation of "Oh - a train just passed my signal pole, thus my block must be occupied"...
BTW how does the sim know how/when the block behind a signal is no longer occupied i.e. train completely past? And regarding the debate about how to represent overlaps (move the sig pole and interactive apart), how far can this be done? Not that I feel that's quite the right solution, as the overlap needs to be 'coupled' to the block ahead.
Just curious at this point, and awaiting the US release when I can research and tinker...
EDIT: Just read Ordan's post, which appeared as I was writing. No yellow/green? Argh - I need those too (repeaters in LUL parlance - yellow warns of a red semi or auto ahead). I was also checking a few of my LUL signal diagrams -- overlap distances on starters are typically around 70m (assumed speed accelerating from a stand being about 25mph at that point), and full-speed overlaps on signals approaching platforms could be 200m given approach speeds ranging from 30-45mph.
I'm itching to get RS and look at all this. I know how to code signal logic (having built the LUL signal set), but if the underlying features and capabilities (e.g. test block occupancy, test route set, etc.) are implemented in 'an unusual manner' (flawed assumptions and underpinnings?), this could all be tricky at best.