Transport Tycoon Forums

The OpenTTD-wiki does not yet have any info on Path Based Signals and I find them a bit tricky to use. For normal tracks I found out how PBS are supposed easy to use, but for a more complex usage in a ro-ro-station I fail. I want to combine PBS and Pre-signals so no trains can cause lockups at the entrance. However, mixing PBS and pre-signals achieves nothing at all. Perhaps these two aren't supposed to be mixed, I'm not sure.

To see what I mean, have a look at the attached image. What I'm asking is if it's possible to add a PBS so the train in yellow can enter the station while the track zone is occupied by the other station-entering train.

Is it possible to achieve what I want?

do not mix block and path signals, use only path signals

if a train stops at a signal where it blocks traffic, remove that signal.

Replace the two pre-signal entry signals with PBS signals and remove the four pre-signal exit signals.

Replace the two pre-signal entry signals with PBS signals and remove the four pre-signal exit signals.

if u do so u can remove the depot also
i tried something like that - its running nice, but the trains never will go into the depot. it seems that with the pre-pbs-signals the trains are searching a way to the next signal - and the depots have a pre-signal in it which doesnt count for it? correct me if i'm wrong - playing 0.7

ps - sorry for my bad english - i', german

petern wrote:Replace the two pre-signal entry signals with PBS signals and remove the four pre-signal exit signals.

Thanks, this does what I want.

bos wrote:The OpenTTD-wiki does not yet have any info on Path Based Signals

yes, it does: http://wiki.openttd.org/Signals#Path_Signals

I was reading this page: http://wiki.openttd.org/Building_signals (which I got to by clicking "Manual" on openttd.org, then Gameplay, then Placing signals in the menu to the right).

Ah, that's the tutorial section. I found the page I was referring to via Main Page > Manual > Signals. Granted, the page you were at could do with a link to the PBS stuff.

I found using PBS as generally best in all situations. Consider this (mind my obsession with cargo specific platforms):



Only one PBS is handling all platforms and there is no risk of jam nor waste of time if the track to the platform is free. The one in the yellow circle is there only because it is too far and train could safely stay there.


I have another question though. What is the advantage of pre-signals over PBS? I was thinking a lot about it and figured nothing. So in which case it is better to use presignals, I might be missing something? Thx.

resurrection wrote:I found using PBS as generally best in all situations. Consider this (mind my obsession with cargo specific platforms):



Only one PBS is handling all platforms and there is no risk of jam nor waste of time if the track to the platform is free. The one in the yellow circle is there only because it is too far and train could safely stay there.


I have another question though. What is the advantage of pre-signals over PBS? I was thinking a lot about it and figured nothing. So in which case it is better to use presignals, I might be missing something? Thx.

I asked before about the advantages, if any, of block signals generally and was told that they place less of a burden on your CPU than PBS. There don't seem to be any gameplay advantages.

you have more control and can create greater logic! (search for logicgates)

dihedral wrote:you have more control and can create greater logic! (search for logicgates)

Such as? I cannot find anything, can you provide a link? I am really interested in cases where pre-signals can do the job (or do it better) then PBSs.

search the coop wiki for priority signalling.

most "normal" users should get away with only using path signals

resurrection wrote:

dihedral wrote:you have more control and can create greater logic! (search for logicgates)

Such as? I cannot find anything, can you provide a link? I am really interested in cases where pre-signals can do the job (or do it better) then PBSs.

You could build a 50%/50% loadbalancer logic gate.. basically meaning that trains on line 1 get split to line 1a and 1b equally .. if one clogs up they won't get assigned to it.


i'll see if i can get a standalone version of it running so you can see it in action.

2Eddi: I am familiar with coop's techniques, but all of them can be done via PBS as well.

2Xaroth: Thanks, that would be helpful. As for 50% balancing, see my image posted above. If I did not use cargo-specific platforms (and even if I do actually), it would work (and works) the same way and still using just one PBS signal. Since PBS assign train only to valid path, there is no possibility of getting assigned to invalid or cloged one.

But you are right, I need to see it in action to understand as there clearly need to be reason why there is both options available

resurrection wrote:2Eddi: I am familiar with coop's techniques, but all of them can be done via PBS as well.

Very obviously you are not. Eddi named the most obvious one, dihedral another.

PBS may offer many no-brain solutions, but there's a number of cases where the block signals are superior and offer more flexibility - as is, of course, a number of situations where it's the other way around.

http://www.openttdcoop.org/blog/tag/logic-gate/ <- have a look at that

resurrection wrote:2Eddi: I am familiar with coop's techniques, but all of them can be done via PBS as well.

2Xaroth: Thanks, that would be helpful. As for 50% balancing, see my image posted above. If I did not use cargo-specific platforms (and even if I do actually), it would work (and works) the same way and still using just one PBS signal. Since PBS assign train only to valid path, there is no possibility of getting assigned to invalid or cloged one.

But you are right, I need to see it in action to understand as there clearly need to be reason why there is both options available

Have a look at the OpenTTDCoop games, specifically the last few games... in the current (145) they made a basic 'counter' using logic gates... should get you on your way.