Priority Merger?

[mild torrent]

Is there a way to make a priority merger in this? When you merge 2 belts normally the inputs alternate. I'd like to set something up that instead favors one input belt whenever it is available and only ever accepts shapes from the second when the first has a gap in the flow. I tried using the Belt Reader to detect whether a shape was present on the first input and then a Belt Filter to only open the second when the signal was absent, but the Belt Reader output appears to persist through gaps in the shape flow, rendering that a non-starter. Is there an alternative I am missing?

Use case: I'm looking at the first-tier research station in Manufacture mode, and it looks like I should be able to loop the "trash" shapes through the process and only feed in the other half. However, that still needs a supply of trash to bootstrap the process. I was hoping to automate this such that I can hook up an input and it will simply stop accepting fresh trash once the loop is fully saturated.

[swift pilot]

As long as the top belt is running, the bottom belt is stopped. When the top belt is empty, the bottom belt runs.

And, uh, that is literally the exact block I use to make the trash input stop in my trash amplifier feedback loop in Mfg Mode.

@mild torrent

[mild torrent]

Huh. I tried something very similar, arranging for the top belt to be half-full and the bottom belt never got to run because the belt analyzer signal never stopped

will build your exact setup to test

Yeah, this doesn't work for me

if the top belt has half the shapes it could carry, the bottom should fill in the rest, but it does not because the signal is never going away

It only seems to kick in if the top belt is less than half saturated

At 1/4 full top belt the output is fully saturated as the flow meter signal turns off for long enough to fill in all the gaps. But at 3/8ths full it still leaves gaps:

I ended up doing this instead, which repeatedly merges the bottom left belt back in so that if both are saturated only 1/384th of the output is from the bottom right input is taken, followed by an overflow trash setup. Then once everything was bootstrapped I cut off the "fresh" shapes

@swift pilot

[swift pilot]

The one I built really is intended to cut off the lower input once the upper starts flowing. Because I'm using it in a trash amplifier, the steady state will be the upper one flowing at 100% and the lower one contributing zero, and the idea is that I'll only ever need the lower one if something drastic and unexpected happens to the upper flow. Like, "I highlighted the whole thing and cleared contents" drastic.

Maybe a better question is: How are you handling the trash production? Ideally, your top input (the feedback from the output) should be running at 100% before long. What it causing the gap in that flow?

[mild torrent]

this is for a loop with the first tier research station so there is zero amplification, the trash needs to cycle 1:1. To establish a steady flow I need all the belts in the system to fill up precisely and then not accept any further input afterwards

[swift pilot]

Let me fire up MFG mode and grab a shot of what I'm thinking.

[mild torrent]

if you are curious this is the full blueprint I ended up with

you feed it a space belt of WuWu---- shapes

and (once bootstrapped) it does the first tier research at a full space belt speed indefinitely

with no other inputs

in the print all the inputs from the train station are cut since I just copied it out of my factory to show you, they'd need to be reconnected on the 2x1 platforms doing the prio merge to test

Needs XuXu---- to bootstrap until everything is flowing around

The intent of the design is to have something I can drop anywhere with some W shapes and leave running on its own completely independently and disconnected from everything else once it is going

Because the research trade produces exactly as much trash as it consumes, all that is needed in the steady state is to polish it again and send it back around

[swift pilot]

Right, so what you're doing is the first one. I thought you were doing the second one.

The second one produces 2 trash for 1 polished trash.

You're saying that the belt never fills up completely? I can see that as a possibility. You could avoid it by making the filter more complicated, but it was designed for a case where the output was larger than the input.

This will never completely cut off the input, though:

[mild torrent]

Yeah, that's why I do it by hand once things are all set

Not ideal but better than having persistent small gaps in the cycle as the version you were using will produce if used in a situation like this general design

I will keep your idea in mind for when I get around to building trash amplifiers, currently not quite far enough along to need them

[swift pilot]

Yup. Mine will have small gaps if the second input never reaches 100%, and it won't, without the trash amplification effect.

Solution: do the feedback with priority merger on a trash amplifier and use these as normal polishers.

[mild torrent]

In my use case I expect to have a train line delivering the bootstrap trash that needs tearing down anyway so this is just an extra small step in the "bootstrap phase complete" checklist

[swift pilot]

As in, on the output of the trash amplifier.

Keep the priority merger circuit handy, though, it will help in Mfg Hard Mode. 🙂

[mild torrent]

Still sad that there is neither a built-in prio merger nor a wire tool that can detect small gaps on a belt

[swift pilot]

there's a way, actually: Overflow splitter on the north input before the belt reader.

[mild torrent]

Yeah I did a Classic Hard run when 1.0 dropped and going to Mfg Normal is a vacation of sorts by comparison

[swift pilot]

So the reader will only trigger if the north input is backed up.

One second, I can show you what I mean

[mild torrent]

I get it, that is something I may have to experiment with

good call

[swift pilot]

I use that trick in my hex smart swapper to detect when an output is blocked vs just flowing.

[mild torrent]

I have done a similar dance in Factorio

[swift pilot]

This:

(I know you said you get it, I just wanted to make it)

Can actually save a spot....