How is the filtered-stack-inserter filter chosen?

[bcwhite]

Factorio v1.1.6

I'm trying to understand how "set filters" works with the filtered-stack-inserter. I know it ignores signals with negative values, but other than that, how is the single item selected from the positive signals?

I ask because I have a chain of filtered-stack-inserters with "set filter", all connected together with both red & green wires, that are receiving a 12k "iron ore" signal on red. Due to a bug, one inserter is configured "none" and manages to pick up some coal. Then, because "read hand contents" is also set, it pulses a value of coal=12 on both wires to all others in the chain. Despite the fact that there is a 12K value on red, it's the (double) 12 value that takes precedence and designates the filter of the others in the chain.

What is supposed to choose the filter for these inserters? Is it the largest value or is it the most recent value? If the latter, what happens if that most recent value goes to zero?

-- Brian

[foamy]

It's done by the internal signal index order, which corresponds, I believe, to the order in which items are listed in your crafting screen. For example, a U-235 signal will always override a U-238 one.

[bcwhite]

Thanks. Too bad it doesn't rank it by signal value. That could be useful sometimes. Not a big enough benefit to justify the cpu cycles, I guess.