Signals, barriers and blocks

A block publishes, under its name, whether a train is standing in it. A signal, a barrier, or a lamp reads this name and sets itself accordingly.

Blocks

A block is an annotation like a highlight or a tunnel: you place markers on the track, and Raily works out how far the block extends, through switches and across element boundaries.

In the toolbar's annotation button, choose Add block annotation.
Place two markers on the track that are meant to bound the block.
Right-click → Refresh annotation.

All markers are initially named block, so a pair immediately bounds a block. Only once you need a second block do you give its markers their own name, under Region name, such as approach or block2. A marker only bounds blocks of its own name, so two blocks may overlap or lie inside one another.

A block with no name cannot be addressed

The name is the only way a signal finds the block. Delete it, and the signal reads an unknown name — and an unknown name is false, so the block counts as clear, no matter how obviously a train is standing in it.

A block draws nothing, or a layout full of blocks would be unreadable. If you want to see it, give it colors in its parameters.

Signals

Add Signal, in the Railway multi-tool button of the left toolbar, places a two-aspect signal, stop or clear. It attaches to the track next to where you place it, and the side your pointer is on when you drop it decides which direction of travel it controls (the one the arrow on the track points in). If it ends up controlling the wrong direction, drag it once across the track to the other side.

Left-hand traffic: use a negative offset across track

Offset across track defaults to positive, so the signal stands to the right of the direction it controls — right-hand traffic, as on the continent. Where traffic drives on the left, in Great Britain or in Japan, enter a negative value; then the mast stands on the left, and the pointer side at drop time means the opposite accordingly.

The value that decides is called Clear when:

Clear when	Meaning
(empty)	always clear: a signal nobody has configured yet stops no one
`!block`	clear as long as no train is standing in the block `block`, the normal case
`!block \| !approach`	clear as soon as either of the two blocks is clear
`false`	always stop

The signal sets itself while the animation runs: what you see is always the current state.

A signal is only read automatically by trains when it is bound to the track

No matter where it stands, the signal shows whether the block bound to it is clear, but trains driving automatically only see it when it is connected to the track.

Barriers

Add barrier, from the same multi-tool button, places a level crossing. It reads the same kind of condition, just named the other way round, Open when:

(empty): always open.
!block: closes as soon as a train enters the block, and opens again once it has left it.

Swing time (s) is the time the boom needs to swing. So place the block marker a little ahead of the crossing.

Speed limits

A speed limit is again an annotation, placed like a block: Add speed limit annotation, two markers, refresh. Its value is a real km/h figure, the number that would be on the sign, not a number in plan units; Raily converts it via the scale, the same way the speedometer in the cockpit does.

Limits may overlap and nest inside one another; a 40 through the station within a 60 on the line is the normal case. Where several apply, the lowest one governs.

Mandated speed turns the limit into a target: a train running automatically then not only brakes for it, but also accelerates up to this value as soon as it is allowed to. Useful for an acceleration zone after the station.

What a train does with this

In the train panel, every train has Signals: with two states:

Setting	Behavior
Automatic	The train brakes on its own for signals at danger and for limits, and moves off again when the signal clears. This is what lets a layout run unsupervised.
Manual	You drive; Raily only reports: “A train passed a signal at danger,” “A train is over the speed limit.”

A name set by hand: the switch

Add Switch, in Building parts, sets the name found under Drives condition: latching (one click on, the next off) or as a push-button, which holds it only for as long as it is pressed. It is pressed in the plan for as long as the animation runs. A lamp with Lit when light is a light switch of this kind, a barrier with Open when !gate a gate switch.

The language, in one paragraph

Wherever a condition appears — Clear when, Open when, Lit when — the same rules apply:

Names are whatever the plan knows: the names of your blocks, and day, night, twilight, dawn, dusk from the sun's position.
true always means yes, false never.
! not, & and, | or, plus parentheses: !block & !approach.
Empty means true. A signal with no condition is clear, a barrier with no condition open.
An unknown name is false. Deleting a block therefore does not turn a signal red — it leaves it clear.