Train Stop Auto Circuit Connection

Automatically connects every train stop to a circuit network via invisible circuit wires — no manual wiring required.

Why this exists

Train stop schedule conditions read signals from the circuit network. If a stop is not connected to any network, Factorio treats all signal values as undefined — which means a condition like S = 0 evaluates to false, even though no signal has been sent.

This is rarely what you want. The intuitive expectation is:

"If nobody has told this stop anything, the signal is zero."

Connecting a stop to a circuit network — even an empty one with no other devices — fixes this. An empty network returns a defined zero for every signal, so S = 0 correctly evaluates to true by default, and only becomes false when something actively sends a non-zero signal.

This mod does that connection automatically for every stop in your game, so you never have to think about it.

How it works

When a train stop is placed, the mod spawns an invisible, inactive constant combinator at the same position and connects it to a circuit network. The combinator:

• is invisible — no sprite, not shown on the map
• is inactive — removed from the engine's per-tick update list, costs no UPS
• cannot be selected, deconstructed, or blueprinted
• is automatically removed when the train stop is mined or destroyed

Existing stops are connected when the mod is first enabled on a save.

Why not just connect stops manually?

You can — but you have to remember to do it for every stop, on every surface, every time you expand your network. This mod makes the correct behaviour the default so you can focus on your train logic instead.

Performance

The hidden combinator is set inactive immediately after creation. An inactive entity is removed from the engine's per-tick processing list entirely. The circuit network that results from the connection is static and empty, so there is no measurable UPS impact regardless of how many train stops you have.

Save game compatibility

Adding this mod to an existing save: safe. On save game load, all existing train stops are automatically connected.

Removing this mod from a save: safe. Factorio will delete the hidden combinators when the mod is no longer present. Your train stops return to their unconnected state — unless they are connected to other entities.