LTN Trains

[ruby hill]

I am going to experiment too. But basically my trouble has been that I have not been able to get that wildcard to work

how would the station know its full?

[quasi oyster]

Train limits

[spice kestrel]

I haven't gotten into it much, nor really processed the screenshots yet but the setup I have in my head is that I'll use signals with radars to communicate how much of each resource is in the train network on the surface, then maybe using logic to allow trains to go to loading stations when the requesting station(s) need enough resources and the loading stations have enough resources. I may be overcomplicating it though.

[quasi oyster]

It's definitely possible that way, but I'm wondering if it's possible without a global circuit net

Just for fun

I feel like it may fail in this situation:
2 providers are open, 1 requester is open
Two trains will head to providers, but only one of them will be able to go to the requester

Trains only fill the limit on the very next station they are headed to, not their entire route

[ruby hill]

This is what I currently use. I am currently though trying to do a pure interrupt system like the screenshot to see if it works because it would be more simple

[quasi oyster]

Wait, is this issue fully impossible to solve in vanilla? I can't imagine any way to limit a station that will have a train headed to it in the future, without also preventing said train from going to it in the first place

[ruby hill]

Huh, so far replicated the screenshots and the trains are not working. Did you get this setup working or just all theory?

[quasi oyster]

All theory

If they worked, I wouldn't be asking if they worked on discord

Also, did you add that waiting condition I forgot? In the first image

[ruby hill]

like waiting until full for the passive provider? yeah, the main problem is the conditions failing

I have no idea how the item wildcard actually works tbh. Only the circuit wildcard

[quasi oyster]

Wait, I think I know
The "wildcard item" thing only checks items in the train's cargo

So if the train is empty it doesn't do anything

[ruby hill]

yeah that is what I thought when I was first using it, but you are not the first person to try it this way. I also was trying to do this yesterday

It would be nice to do it this way though because then you can have a seperate interupt schedule for fluid trains

[quasi oyster]

Luckily I've already seen something that can help get around it
A combinator setup that is wired to every station in the depot, that repeatedly cycles between every single item that's being delivered by the network

Then replace wildcard item with wildcard signal, in the first interrupt

[ruby hill]

yeah that is what I currently use

• this for figuring out if I need to send a train or not. Red wire is for supply and green is for demand

I didn't figure out how to combine the red/green wire in one signal tho

[quasi oyster]

Well, there's no global net required, only a contraption at the depot
I consider this a win

[quasi oyster]

I suppose there is still this thing, but like I said that may be completely out of the realm of possiblity

[ruby hill]

wait I missed you saying

A combinator setup that is wired to every station in the depot, that repeatedly cycles between every single item that's being delivered by the network
This is kinda cursed 💀

[quasi oyster]

It really is

But it should work

[ruby hill]

The global network really isn't that bad, the radar can transmit signals wirelessly

[quasi oyster]

I know, I know

[ruby hill]

I will try out the repeatedly cycling though it sounds funny

The dropoff should be able to stay the same though since the item wildcard takes from the inventory

[quasi oyster]

I think the first interrupt should actually have "not at pickup" instead of "at depot"

Right

That's the first thing people figured out with interrupts

Pull-based logic is what we're really after

[ruby hill]

I actually switched to that later due to the inclusion of fluid trains so I could share the interrupt better. Then trains could sit at whatever depot they want (and the fluid trains were at fluid depots)

but what is the least cursed way of cycling through a list of items without doing clock and manually setting every single item

[quasi oyster]

Also, I didn't even realize you could do this in a single interrupt, I added the second one for no reason. Lol

[ruby hill]

So many people split it into two (dropoff and pickup) that I got convinced into thinking doing it all in one is bad lol

[quasi oyster]

Hmm... Unless...

Ah, I think I remembered why

[quasi oyster]

This whole thing

If a train is filled, but can't go to a requester, it will go full to the depot

And then that interrupt will send it to a requester as soon as it opens

[ruby hill]

This should generally be okay so long as you don't overfill requester depots

so it probably wouldn't be an issue with 2 passive and 1 requester, but instead like 5-6 passive and 1 requester (and for some reason you are not consuming the items fast enough)

[quasi oyster]

How does stop priority work again

I know trains will go to the highest prio stop first, if they have to choose

But what about trains leaving

If two trains have to go to the same destination and there is only room for 1

Does the stop with a higher priority get to send its train first?

[ruby hill]

ah, found one downside of making the orders all together. I don't think it will replace the requester wildcard for the station name correctly

since at the time the train leaves its cargo is empty

[quasi oyster]

Appears to not be the case 😔

[ruby hill]

I think you can literally send a train a constant combinator of all the items in your train network and then the system you are talking about will work

you don't even need to cycle one item at a time or anything crazy like that

It does kinda suck that you will need to remember to update that constant combinator every single time you add an item

or you can just plop down a radar and send a signal for your provider station. Its more expensive than free but if its apart of a blueprint that means no overhead mentally

so I am legit just sending the train depot this and the trains are going to the coal station. Even though cliff explosive sorts before it

and this is the interrupt

So I guess this is the vanilla you have LTN at home solution

Also, I just use train limit 1 and I disable/enable the station

@fast igloo LTN at home here ya go I guess

oh I can kinda see the issue with the 2 passive 1 requester system. If 2 trains are sent and 1 hits the requester first. The requester station would be disabled making the other train stuck. I only thought of it from being full perspective

@quaint cypress How are you using the any signal for interupts?

like this doesn't seem to work

@south anvil did you do the above?

not the exact above image, but the one above that

Not saying its better, but the main challenge is 2 passive providers and 1 requester. Then 2 trains are sent leading to 1 being stuck with a bunch of stuff because the other disabled the requester station with its resources

[south anvil]

humm no i didnt did that

i dont understand exactly what that is tbh im pretty tired rn i been problem solving in factorio for the last idk, 4 - 5 h? i have now this save over 15h and im not in to space yet, im re learning fractorio jejeje, the concept its really cool but idk if im going to put any more efort for now, maybe when i got the science of at least the 3 next planets ill try to do something like that.

thanks for the help

[ruby hill]

yeah uh, if this happens your train is just stuck at the provider station waiting for the requester station to be reenabled again

[quaint cypress]

https://factorio.com/blog/post/fff-395?form=MG0AV3

[ruby hill]

well to be fair, its waiting for ANY requester station to be enabled. So its not necessarily a bad thing

[ruby hill]

ah yeah this thing. Not really useful for depots though because you don't have any item

[quaint cypress]

You can make an interrupt that if it has nothing in the train and nothing is asking for anything to move to a depot.

[ruby hill]

can you share a picture of that?

or have you not tested this yet?

[spice kestrel]

Is it helpful to have all trains sit in a provider until a requester opens up, and then only allow one train into the requester at a time?

[ruby hill]

Bruh, if there are two train stops with the same name and one of them is full, the train will think both are full

[spice kestrel]

Is that the "any" signal? And is there an "every" signal you could use?

[ruby hill]

I just gave up and accepted that every passive provider station will have a train in it. So I am not using a pull model anymore. The game clearly isn't made to support a pull model and the FFF encourages a push model so that is what I am doing now.

I was using the circuit wildcard. For some reason it doesn't work as well as the "any" item wildcard

So let me know if you get the circuit wildcard working @spice kestrel (What was failing is circuit wild card multiple requester stations with the same name)
Although tbh its not like there is much downside to the push model.
The only downside is I was planning on having a sushi train that stopped at every provider train that it needs. But I can't do that anymore since there are trains sitting at each passive station

I was running this

and then swapping through all the stations I have for the circuit condition (so iron, coal, stone etc)

[spice kestrel]

I will do some testing on the multiple requester stations. I haven't tested this with multiple requester stations with the same name, but this has been working pretty well for me so far. The logic on the train station is disabling it if it doesn't have enough room to unload a full wagon.

Sends em to a depot station to refuel and wait, then they go out to the first available pickup and sit there until they're full and have a valid target.

[ruby hill]

If you switch to pure interrupts and instead only have them to the depot if they are blocked&Empty its a bit more efficient

As they should only go to the depot if there is nothing to do on the network

[spice kestrel]

My base is far from efficient at the moment, so it's all good. 😂

I am simultaneously running out of copper, iron and power. 😅

[ruby hill]

But yeah this was the push model I don't really want to do but nothing else I have done fully works :v

[spice kestrel]

That's understandable, but it's too bad.

[ruby hill]

wait what happens if your trains can't go to any dropoff stations?

[spice kestrel]

They just sit in their pickups waiting for a dropoff station.

[ruby hill]

So wouldn't all your trains just fill up with coal or copper?

if your supply is much higher than your demand

[spice kestrel]

Only as many trains as I have coal or copper stations. They block other trains from using the pickup stations if they've already filled up there.

I have this depot here, 8ish trains and 5-6 pickup stations at the moment so it's hardly a concern for me.

[ruby hill]

as long as your demand is higher than your supply for every resource it should be fine yeah

[spice kestrel]

Why wouldn't it be fine if the my supply were higher? I don't see any issue in trains sitting in the pickup stations with a full inventory.

[ruby hill]

If every single train is full of lets say, coal, in the depot and then there is a demand for iron there would be no trains available to supply iron

[spice kestrel]

They don't go to the depot until they've finished unloading.

[ruby hill]

Well, actually it would be more there would be some trains in the passive provider for iron

[spice kestrel]

The loop is
Sit at the depot until you're fully fueled and there is an open pickup station
Sit at a pickup station until you're fully loaded and there is an open dropoff station
Sit at a dropoff station until you're fully unloaded
Sit at the depot.

[ruby hill]

but you don't check if the dropoff is full or not no?

you are just checking if you are at a pickup and have inventory

so either you will have a queue behind pickup or a bunch of full trains in the depot

[spice kestrel]

I turn the dropoff off if the dropoff is full, but even if the dropoff weren't full the train limit of one would mean that the train sits in the station and disables it.

Full trains never go to the depot. If they don't fully unload they'll get stuck in a dropoff and I'll have to figure out what's wrong there.

[ruby hill]

you do, otherwise a lot breaks. The game doesn't know how to handle multiple items too well its weird. Gotta send it one at a time somehow and cycle through each item. But I suck at circuits to figure out how to do that soo...

[quasi oyster]

Separating load and unload into two interrupts should (in theory) solve this

Let’s say the thing happens
Two trains got filled, only one got emptied
The overfilled train will then go back to the depot
The next time a requester opens, this full train in the depot should be sent to it first, instead of a new empty train being sent to get filled

Oh, but I suppose it doesn’t actually make a difference

This only changes where the full train is waiting, not the number of full trains waiting
In the end, putting both in a single interrupt might even be more practical, as it doesn’t cause unnecessary filling of the depot

[quasi oyster]

So I guess I was right all along about this being fully impossible?
Yay?

[ruby hill]

I fixed the issues I was having by switching to outputting each item one at a time in a clock. Rather than a single constant combinator that doesn't work

So the system you said in theory does work

[ruby hill]

I've seen it be suggested to have full trains wait in a depot, but what scares me about that is you could end up in a situation where all your trains get turned into full coal trains waiting for the requester stations to turn on

Someone earlier here was saying all their trains got filled with copper ore lol

If you need the circuit to cycle through items provided by a constant combinator let me know. But the basic idea is create a clock that goes from T=0 to like 10.
In the constant combinator do iron ore = 1, coal ore = 2 and so on.
Then compare Each to T in a decider and if that is true export each from the decider.

That will cycle the provided list one by one

If you want a 1 cargo long train for nuclear fuel, you can create a new constant combinator and decider with the items you want for 1 long trains. And then assign a new group for the 1 long trains + a new set of depots for that circuit.

This is also how you can do fluids too

I might do a video on this because I have not seen a single person do a pull based system in vanilla yet like this. It's the easiest way

I plan to eventually use the system to make a sushi train that goes to my passive stations. So I was super motivated to make the system be pull-based instead of push like the game is forcing us to. Push is much easier to do (just follow Factorio FFF above), just less convenient

I am curious how pull/push will do once I get to spoilage. Pull might be better because you could instead move based off time in station instead of full. Whereas you always have a train stuck at providing with push even if you don't need it. Or neither will work and I am forced to use belts

[ruby hill]

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

This is an example clock for going through a list of items from a combinator for your trains

Whenever you add a new provider/request station you need to update the constant combinators with the new item. You can add new constant combinator+decider if you want a new set of trains with a unique property. For example you could make a new group with 1 wagon. A new group for liquids. A new group that waits a stations for 20 seconds instead of wait until full and so on. But it has to be done on a per item basis.

[ruby hill]

nevermind the constant combinator does work it was missing some wires

[rocky tendon]

@ruby hilldid you ever figure out a pull based system for trains? i'm currently working on trying to build my own and have a working system that only dispatches trains to providers when a requester needs resources, but am trying to prevent the depot stations from becoming massive congestion bottle necks as each train must pass through them first before knowing where to go next

[ruby hill]

This is my solution https://www.youtube.com/watch?v=C3HBa20a5Io
It avoids any global circuit system in favor of simplicity.

There is a bottleneck for each train passing through depots yes, but you can just make more depots. It hasn't been an issue for me especially with train limit 2

I actually beat the game with this system for the most part too. My nauvis base works great

Generally ran 180 SPM

You can make this system more complex and with less train oversending but tbh its hardly an issue. This is good enough

Nowadays I am just learning to use CyberSyn since I beat the game already with this. Train interrupt system is cool but overcomplicated

[rocky tendon]

interesting! this is definitely similar to the solution i keep on finding myself drawn to as it is so simple
i really want to try and find a way to cut out the depot middleman, not really for any gains in efficiency, just because i keep on seeing glimmers of hope that it is possible in vanilla and want to try and do it
haven't heard of cybersyn but i'll definitely give that a look!

[quaint cypress]

I'd say it's super simple lmao

All you have to do is adjust the station name and it pretty much works..

Blueprint station limits and have circuit conditions to that, super simple

And a lot more simple than LTN essentially

I miss my multi-deliveries though

[rocky tendon]

wdym?

[quaint cypress]

The train is scheduled to go to Item Input

There's an interrupt that checks if cargo does not equal to 0, and if it isn't 0 it will replace the Any item icon with the first item it finds like you displayed in your own video

And schedule itself to that trainstation that's named

You can essentially run this with 2 interrupts and 1 station

[rocky tendon]

that is a push system...

[quaint cypress]

Yes

The interrupt system prefers pushing, LTN it's done by pulling

The whole argument is that it was overcomplicated, to which in essence it really isn't.

I've seen more people struggle with the idea of LTN than this system, although I heavily prefer LTN

[rocky tendon]

yeah, ultimately i think this is one of the simplest ways to make a train system now. i just personally would like to create a vanilla pull based system
also, i really dislike that with that system all providers need to be named the same :(

[ruby hill]

I specifically did pull using the interrupt system to allow for sushi trains

[quaint cypress]

LTN sushi trains are much easier to do given the fact that you can do way more with circuits and the train sets the demand of items it needs based on what the requester wants.

If a requester needs 5 furnaces, 4 inserters, 20 belts, 50 walls, 5 lamps, the train can be scheduled and pick up that exact order if you do it right.

[ruby hill]

I mean vanilla sushi trains are not hard either you just have to filter the wagons

[quaint cypress]

Yeah, sure, but what about using no filters at all?

https://www.youtube.com/watch?v=WfrS-Q8KYbo I have it on display here

[ruby hill]

But my point really was you can do pull in vanilla and it's better because you can use sushi trains easier

[quaint cypress]

I use a ghost scanner to scan a cell what it needs for construction

It schedules a train to pick up those exact items from the mall

And then dumps it in the requesting logistics network

Effectively linking all logistic networks together without having to configure a specific train to load those items on

(I wish they made ghost scanning vanilla but oh well can't have everything)

[ruby hill]

For my train picking up items from the mall for the wall defense I did something similar using vanilla interrupts and a sushi train. It only went to the walls when there was a demand for an item

Sure it's not perfect but it doesn't need to be

[quaint cypress]

But you set up a specific train group for that that is preloaded those items with filters right?

[ruby hill]

Yeah I did. But it's just one train I don't need more

[quaint cypress]

I don't need to configure a separate train with LTN

I just do multi-deliveries

[ruby hill]

I mean I know how LTN works

I also used it

I still think it's more simple

[quaint cypress]

The interrupt system or LTN?

[ruby hill]

LTN

[quaint cypress]

Agree to disagree then I guess

[ruby hill]

I spent like 20 hours figuring out the vanilla interrupt system just to get something imperfect

LTN I got working in a basic way very easily

[quaint cypress]

It took me 10 minutes.....

But that's because I read all the FFF's leading up to this patch so

I knew exactly how it worked before I got to play with it

[ruby hill]

So did I

[quaint cypress]

I just wish there was an additional signal that I could send towards a station for it to raise the train limit to be able to do multi deliveries

[ruby hill]

I think the difference is I want interrupts to work a specific way to allow for sushi trains

[quaint cypress]

Instead of Any Item signal picking the first item

Fill an array that I can use

[ruby hill]

If you just surrender to how the devs want you to use it then yeah no work needed

[quaint cypress]

I reckon it's possible with a roboport, constant combinator and a radar.

But, shit, much effort

I'd have to give every station an ID and if the train content matches a specific cells request from the drone bay (to which it doesn't do ghost scanning) Ican raise the train limit, but all my recieving train stations will have to be named the same

And there's ofc the possibility of the train being misscheduled to another station when like 4 trains go at the same time and 4 recieving stations are able to recieve a train.

Yeah, or, you create a scheduler that works over radar

So every train that needs to be scheduled gets put on a list, and it queues the trains 1 by 1 to go to the specific stations, Train ID A4021 meets the request for Station B90, so all train limits are 0 except for that station, train limit is raised, train leaves station and thus it's going to destination, next trian that is in the queue is then scheduled to meet demand of station x and so forth

[rocky tendon]

girl, i'm really confused what/if you're trying to argue?
obviously using interrupts to make a push based system is super easy, we know that. a pull based system is just more appealing to us so we spent the effort to try and make it work in vanilla. it is very possible as @ruby hill demonstrated in their video, and all i want to do is try to cut out a small inefficiency

[quaint cypress]

Who are you calling girl lmao

I'm not trying to argue anything.

Maybe that's why you are confused about it

[rocky tendon]

okay, then i don't understand what you're trying to add to the conversation? a push based system is antithetic to trying to mimic LTN... which is the topic of this thread...

[quaint cypress]

It's about multi-deliveries that I can do with LTN

LTN does more than just pull, I was the one that kind of started this thread with some other guy when 2.0 hit...

Because I kept talking about LTN in space age and comparing the interrupt system to the capabilities LTN has.