Factorio Forums

I've been working with rail signals with wire and discovered an odd bug in the signal logic when they aren't attached to a track. This applies to both the regular and chain signals. When they aren't attached or placed in an invalid spot, they flash Green -> Yellow -> Red -> Green. However with them hooked up to wires, they actually output something different. The Rail signals output a constant green signal. As evidenced by the lamp in the attachment. While chain signals output seems to change based on when it was connected. When it updates, it goes to the next color. But it only updates upon receiving a wire update. So usually, it's "green" when it's placed, but when hooked up, it goes to "Yellow" and if I hook up another wire to it, or remove it. The output changes to "red" while it continues to be animated without the actual signal itself changing.

I think it should be fixed so that it outputs the cycling colors too. It can make a nice simple clock for wiring! Besides, I don't think it's intended behaviour for either of them to stick to one signal while it cycling like that. Especially with the chain signals strange "change on a wire attaching update" behavior.

The behavior applies even to invalid placed signals on tracks.

The behavior goes to normal as soon as it's placed on a track without being invalid.
[EDIT: oops. Forgot to mark the title, but it has existed before 0.17]

This...sounds like it could potentially break determinism. Have you tested this in multiplayer to see if it causes a desync?

Thanks for the report. It's now fixed for the next version of 0.17.