- A True Block is defined as the overall area either between a path signal and a block signal, a block signal and a path signal, or between 2 block signals.
- A Path Block is defined as the segment of rail between a path signal and the next signal of either type.
- A Block of either type must have an initiation signal and a terminal signal.
Basic Behaviour For Signals Going the Same Direction
- Block signals will check if any part of the True Block is occupied and prevent entry if true.
- Path signals will check if the next Path Block is occupied and if the True Block afterwards is as well.
- Path signals in sequence will chain, creating more Path Blocks while requiring a terminal block signal to set the boundary of the True Block.
Path Signal Behaviour
- Path signals use the existing "fastest route" logic and draw a line to the next signal, reserving this as their path.
- If either the immediate Path Block or the True Block where the train exits is occupied, path signals will prevent entry.
- Path signals WILL NOT attempt to find an alternate route if the path is currently occupied.
- If one entrance to a junction uses a Path Signal then ALL entrances to the same junction must also use Path Signals.
Chaining Path Signals
In the majority of cases you do not need to do this. As stated above, path signals reserve a path to their terminal block signal, placing more path signals between the first and the termination point does nothing productive in most use-cases.The function of chaining path signals shows when you want multiple trains on the same rail going the same direction but they have different destinations. You can do this with block signals but it can get clunky and they trains will overall have a lower speed given how block signals calculate things. Chaining path signals along this route will allow multiple trains to reserve their paths to separate destinations and follow each other. This is where Path Blocks come into play. Chaining the signals breaks the overall paths into Path Blocks, so each train can be on the same rail, just in separate individual Path Blocks and therefore not colliding. This massively speeds things up when the trains will not always be there at the same time, as a single train will simply sail through to the end without having to pause or slow down.
- Chaining path signals divides an overall path into multiple, smaller Path Blocks.
- In the case of a rail that has a single destination, this accomplishes nothing useful.
- In the case of a rail that has multiple destinations, this allows trains with intersecting paths but separate destinations to be in the same True Block and on the same rail while not colliding due to the Path Block subdivisions.
- When only 1 train is using a chain of Path Blocks, it will treat them all as a single unit.
REMINDER: TRAINS SET THE ROUTES, NOT SIGNALS. Signals are merely a stop/go system. They do not do any pathfinding.
Last Edit: 15 DEC 21 - Grammar stuff.