Factorio Forums

I'm having a hard time designing a refueling station that works while transitioning from coal to solid.
I tried to use the generic fuel item, but my train was stuck at refill because coal below threshold and no coal available at station.

However, I may have discover a bug while trying to find a workaround. It seems if the generic train fuel gets mixed with generic item read from station.

This broke the interrupt and made the train ignore it's low fuel state

You added "circuit condition [generic fuel] = coal", in the interrupt conditions, but how is that supposed to work when the train is en route? Circuits are sent to train on stations. Your circuit condition should not be fulfilled as far as I'm aware.

This is certainly more of a gameplay help question until a lot more description and a savefile are provided.

The condition "Circuit wildcard = Coal" actually means that "any circuit signal with a nonzero value sent to the station I am leaving that equals the value of the coal signal sent to the station I am leaving will make the condition pass, and that item (which is probably coal) will be substituted in any interrupt schedule entries that also use the circuit wildcard symbol".

I don't know what it was intended to do at all. Based on the train stop screenshot with a chest of solid fuel wired to a train stop, I think they made this with some major misunderstandings. I hope OP has figured some more about how the interrupt works since they posted this.

The shortlist of those insights being:

1. The interrupt will be added to the schedule if and only if, when the train LEAVES any station, the conditions are met AT THE STATION IT IS LEAVING.
2. The circuit wildcard only looks at signals being sent to the station THAT THE TRAIN IS LEAVING. It cannot read signals at potential destination stations.
3. The fuel wildcard is essentially useless because it can only match a fuel item if there is still some fuel left in the locomotive. The only advantage it brings is that if there IS fuel left in the locomotive when the interrupt triggers, then that fuel can be substituted into a train stop name. But if the locomotive ever starts burning its last unit of fuel, and the fuel inventory is empty, there is no longer any item to match the fuel wildcard. It will always be more useful to put actual items in the "Fuel" condition, so that it can trigger when that particular item reaches 0 count.