old LTN discussion thread

[Optera]

I'm really enjoying trying out this mod.

I had a question on how to handle a situation though. If my network is train limited, ie my provider station is always full, and my requester station is constantly requesting much more than the size of my trains, yet the trains can't catch up, it gets stuck in a pessimistic state where each train is carrying only slightly more than the minimum delivery, and won't fill up.

For instance, my requester is requesting 8k iron, I'm using little LCCL trains (4k capacity) and minimum delivery is 2k. There is a huge surplus of providers. I will always end up with 4 trains in flight, together they sum up to the 8k delivery. But each one only carries around 2100-2500. Maybe this won't be possible until 0.15, but in theory you could have the LTN observe the train contents, and have the train schedule trigger on a signal sent from the LTN instead of directly on cargo quantity, so that you could dynamically adjust load amounts even after the train is dispatched, instead of scheduling a new train.

I guess I could use my own circuit system to detect this condition somehow, and bump up the minimum delivery size dynamically, when it detects starvation? This is just me playing around on a test map, in a normal base usually for ore the train isn't the limiting factor. But I could see scenarios when using trains for intermediates in a megabase where you'd have problems.

Has anyone else tackled this or have any suggestions?

EDIT: Is it as obvious as my request size is too small? If my trains can't keep up it means the buffer I was requesting isn't big enough for my consumption rate. There must be some way to approximate that number so I can get deliveries in time without excessive buffering or train usage.

If I read that right you have trains running half full with both providers providing and requesters requesting more than their capacity. Perhaps you managed to get LTN into that narrow spot where current deliveries only manage to trigger the ~2k deliveries.

As you noticed min Delivery size has a huge impact on how well trains are utilized.
To make sure trains mostly run full, I'm setting min delivery size equal to capacity of the smallest train I want LTN to use. Only shipments of more expensive products, like control units, warrant shipping before a full train load is required.

Buffer size depends on trains RTT (depot-provider-requester-depot) and (un-)loading speed at stations. Usually for ore I'm going for ~80k since I really don't care if it's lying around at my furnace station or the mine.

[gridstop]

If I read that right you have trains running half full with both providers providing and requesters requesting more than their capacity. Perhaps you managed to get LTN into that narrow spot where current deliveries only manage to trigger the ~2k deliveries.

As you noticed min Delivery size has a huge impact on how well trains are utilized.
To make sure trains mostly run full, I'm setting min delivery size equal to capacity of the smallest train I want LTN to use. Only shipments of more expensive products, like control units, warrant shipping before a full train load is required.

Buffer size depends on trains RTT (depot-provider-requester-depot) and (un-)loading speed at stations. Usually for ore I'm going for ~80k since I really don't care if it's lying around at my furnace station or the mine.

Thanks for replying.
Yeah in this weird pessimistic case you'll end up with something like (request / min delivery size) trains in flight always. Even if possibly the trains could keep up if they were fully utilized, they never will. But this is only due to having a smaller min delivery size than train size on what is supposed to be a high-throughput channel.

As you say, for cheap bulk materials, just use min delivery size == train size. I suppose this could have issues when dealing with different size stations/trains? Do you have to force the smaller trains/stations to higher priority to ensure they get used, even if they are lower than the min delivery size of the requester? In all honesty, I probably will not use omni-sized requesters for bulk materials, I'll have different requesters for each size. Though if you have a common request amount feeding into them, the small trains/depots will get utilized more heavily since they'll trigger first always. This is probably good since you're generally upgrading in train size as the game goes on, and you want to use up & decommission the smaller trains & outposts.

Once again, I'm really having fun experimenting & happy that this mod exists.

[EoRaptor]

According to Ssilk, smarter trains somehow conflicts with LTN.
I'll check the mod pack out when I find the time.

Yes, but as i mentioned smart trains was switched for logistic trains. We only have logistic trains active on the map where the desyncs occured.

[steinio]

Hello,

don't know if this is a bug.

After delivery LTN don't deletes the timetable.
Instead the train drives back to the depot and queues in line with other waiting trains. Now the schedule times out because the waiting trains before it blocks the scheduled train.

Suggestion: Delete schedule after delivery and asign a new train if neccessary.

Greetings steinio.

Edit: This time it seems it's only a cosmetic issue. The schedule exists but is not active.
Sorr i'm getting to understand the system very slow.

[Ghostling]

First of all. love the idea of trains to be used the same way as robots.

me and some friend have been running a map for awhile now (61 hours) but we had a problem with the mod, trains kept delivering goods while it was way past it's requested size (20K requested 100K delivered and counting.)

when this happen trains started to go to that station thinking they could load there....

well, we thought maybe an mod update should fix that, but was a little too fast on the tricker and forgot to backup the old mods first. so is there a way to rollback to version 0.9.2 ?? evry player desync when the mod makes new schedules

thanks in advance

Ghostling

[Optera]

Hello,

don't know if this is a bug.

After delivery LTN don't deletes the timetable.
Instead the train drives back to the depot and queues in line with other waiting trains. Now the schedule times out because the waiting trains before it blocks the scheduled train.

Suggestion: Delete schedule after delivery and asign a new train if neccessary.

Using stackers seems oddly popular.
Once trains arrive back at the depot deliveries and schedule are reset in one go. I guess there's no harm in deleting deliveries once they depart the requester apart from loosing a potential warning of trains getting stuck on their way from requester to depot.

First of all. love the idea of trains to be used the same way as robots.

me and some friend have been running a map for awhile now (61 hours) but we had a problem with the mod, trains kept delivering goods while it was way past it's requested size (20K requested 100K delivered and counting.)

when this happen trains started to go to that station thinking they could load there....

well, we thought maybe an mod update should fix that, but was a little too fast on the tricker and forgot to backup the old mods first. so is there a way to rollback to version 0.9.2 ?? evry player desync when the mod makes new schedules

The amount of desync reports I get recently puzzles me. I didn't change anything since 0.7.0 that could in my opinion desync players.
It's a wild guess, but try setting message_filter_size = 0 in config to disable the message filter I recently updated.

Edit: turns out my wild guess was correct. The way I implemented message handling causes a reliable desync when log_output_log_level or MessageFilter don't match between clients.
Until I find a way to fix it, please use message_filter_size = 0 and log_output = "log" or disable messages completely with log_level = 0 for MP servers.

[steinio]

Hello,

definitely a bug:
If a station is overloaded and an other needs this items the dispatcher creates a schedule to get the items from an input station instead from an output station.

[Optera]

Hello,

definitely a bug:
If a station is overloaded and an other needs this items the dispatcher creates a schedule to get the items from an input station instead from an output station.

Working as intended.
Provider: positive amounts
Requester: negative amounts

If you overload a requester so it turns positive it will become a provider.

[Nilaus]

Absolutely brilliant mod. I've been running trains all over my base instead of using robots and I never even knew about this mod.

Most of my stations serve multiple items as they are created together. My issue is when the train arrives it will pick up everything instead of just the material requested. I read a comment on page 2 about this was one of the limitations; skimming through a lot of pages I did not find a clean solution. I have a feeling this can be done by circuit network. Somehow tell the inserters to only be active when a relevant train is in the station, but that is the problem: How can I know which train is in the station is multiple trains are heading there?

I hope someone has already found a solution as I suspect my own circuit network skills are too limited

Example:
http://i.imgur.com/0vjDIfC.png
When a train comes to pick up Purified Water Barrels it will fill up with all the crap being loaded from here

[Optera]

Absolutely brilliant mod. I've been running trains all over my base instead of using robots and I never even knew about this mod.

Most of my stations serve multiple items as they are created together. My issue is when the train arrives it will pick up everything instead of just the material requested. I read a comment on page 2 about this was one of the limitations; skimming through a lot of pages I did not find a clean solution. I have a feeling this can be done by circuit network. Somehow tell the inserters to only be active when a relevant train is in the station, but that is the problem: How can I know which train is in the station is multiple trains are heading there?

I hope someone has already found a solution as I suspect my own circuit network skills are too limited

Example:
http://i.imgur.com/0vjDIfC.png
When a train comes to pick up Purified Water Barrels it will fill up with all the crap being loaded from here

Sorry I've only answered this in German without translation.
You have to use filter inserters, set to filter mode and count the items moved by inserters (pulse read) into a memory cell and subtract the memory cells content from the (un-)loading signal of the LTN stop.

The most basic form of this only uses 3 combinators.

[ssilk]

Suggesting a Way to Pair Stops

This puzzled me yesterday a lot: due to throughput reasons I built at my central factory three of the multi-input-output stations posted last week ( viewtopic.php?f=97&t=36976&start=220#p242703 ). For the audience: their main usage for this is to provide the stuff I construct in my main factory: rails, inserters, furnaces, repair packs, and some more. Before sent into the LTN it is filtered explicitly from the bulk transports, like iron ore. (The bulk is done by other stops with other trains).

This system works very good: I'm able to create an outpost with the size of 500x500 with - let's say - 2000 rails, 200 furnaces, 400 inserters, thousands of different belts, etc. in 15 minutes just by one blueprint and building only the part with the supply station with my personal roboport. Which I find quite cool.

There is a small problem with that: Because of the three stops LTN splits the items to bring into three trains, not one. I think cause LTN thinks that there are 3 different providers - even if they provide the exact same stuff.

But there is just one provision, which needs to be split into three stops, due to traffic jam otherwise.

So I thought to different things to change that and here is my idea:
LTN currently forbids to connect two or more stops together: it sees that two train stops have the same name and turns the lamp to violet. Or it sees the green signal from the other train stop and knows, there is something wrongly connected now and turns the lamps to red. Ok, I can simply send a signal red -1 into that connecting bus. But the stations are still seen as two different stops, I think LTN is currently unable to manage train stops with the same name.

So I thought to this: if you really want to manage some train stops as if they are one (due to traffic reasons), we need to pair them.

And this pairing works more or less as if you want to pair two Bluetooth devices together. And that works basically with these steps:
1. You need to give two stops the same name. The stop light turns purple.
2. You connect the lights of both stops with a wire. In normal case the lights should turn red now. In this case not.
3. What LTN does instead is to send over the violet signal of both stops a random number.
4. Both numbers are added now on the bus and the remaining signal is for example 91+38 = 129. This number is now in the bus. (For three or more stops this is still similar: It tries to pair A with B, then B with C, so A is also connected.)
5. If that number is received on both sides within one tick, then LTN knows there is a direct connection between the stops and it pairs both and handles the stops as if they where one provider/requester in the network (not two, three or more).
6. This is of course not the case for the output box, that works still as now.

[Nilaus]

The most basic form of this only uses 3 combinators.

Thank you for the very fast answer. I think an answer in German would make it just a tad too difficult for me to decipher
I've now spent hours looking at your screenshot, opening the demo save, loading a test map, changing wires and conditions and then repeating it again because it didn't work.

I've finally made it work. The part that threw me off was the 3 combinators you mention above. I thought they were all needed for the count, but the third is for resetting, hence I thought there was an error since it had a condition that wasn't enabled.
I would say the 3 combinators mentioned above are for "Reading the inserter count" (arithmetic), "Accruing the total inserter count" (decider) and "Resetting the cycle" (decider). I should probably make a tutorial of this some time...

In any case, now it works and I simply need to recreate all my 50 trains stops one by one...

[Optera]

Suggesting a Way to Pair Stops

This puzzled me yesterday a lot: due to throughput reasons I built at my central factory three of the multi-input-output stations posted last week ( viewtopic.php?f=97&t=36976&start=220#p242703 ). For the audience: their main usage for this is to provide the stuff I construct in my main factory: rails, inserters, furnaces, repair packs, and some more. Before sent into the LTN it is filtered explicitly from the bulk transports, like iron ore. (The bulk is done by other stops with other trains).

This system works very good: I'm able to create an outpost with the size of 500x500 with - let's say - 2000 rails, 200 furnaces, 400 inserters, thousands of different belts, etc. in 15 minutes just by one blueprint and building only the part with the supply station with my personal roboport. Which I find quite cool.

There is a small problem with that: Because of the three stops LTN splits the items to bring into three trains, not one. I think cause LTN thinks that there are 3 different providers - even if they provide the exact same stuff.

But there is just one provision, which needs to be split into three stops, due to traffic jam otherwise.

So I thought to different things to change that and here is my idea:
LTN currently forbids to connect two or more stops together: it sees that two train stops have the same name and turns the lamp to violet. Or it sees the green signal from the other train stop and knows, there is something wrongly connected now and turns the lamps to red. Ok, I can simply send a signal red -1 into that connecting bus. But the stations are still seen as two different stops, I think LTN is currently unable to manage train stops with the same name.

So I thought to this: if you really want to manage some train stops as if they are one (due to traffic reasons), we need to pair them.

And this pairing works more or less as if you want to pair two Bluetooth devices together. And that works basically with these steps:
1. You need to give two stops the same name. The stop light turns purple.
2. You connect the lights of both stops with a wire. In normal case the lights should turn red now. In this case not.
3. What LTN does instead is to send over the violet signal of both stops a random number.
4. Both numbers are added now on the bus and the remaining signal is for example 91+38 = 129. This number is now in the bus. (For three or more stops this is still similar: It tries to pair A with B, then B with C, so A is also connected.)
5. If that number is received on both sides within one tick, then LTN knows there is a direct connection between the stops and it pairs both and handles the stops as if they where one provider/requester in the network (not two, three or more).
6. This is of course not the case for the output box, that works still as now.

Wow... what a brain teaser. You have a knack for coming up with ideas that make my mind go in circles trying to figure out how to make this work in reality.
I don't think I can make stop pairing work in a meaningful way.

rambling my unfiltered thoughts about potential scenario:
Pairing would only be useful when using a provider using dynamic requester chests and requesters using active providers. 99% of users will simply have belts feeding to/from chests. I don't see how such a setup could handle trains picking one of the station. Players could add a circuit controlled entry signals, but how would that know which item the train will bring....

The BP I gave you only uses one inserter to load/unload. wagons have room for 4 such combinations (with bobs inserters you could have 12 loading and 12 unloading stack filter inserters) That should be more than enough throughput to have only one stop. I'm only using 2 pairs, it's fast enough unless i start requesting >10k concrete

The most basic form of this only uses 3 combinators.

Thank you for the very fast answer. I think an answer in German would make it just a tad too difficult for me to decipher
I've now spent hours looking at your screenshot, opening the demo save, loading a test map, changing wires and conditions and then repeating it again because it didn't work.

I've finally made it work. The part that threw me off was the 3 combinators you mention above. I thought they were all needed for the count, but the third is for resetting, hence I thought there was an error since it had a condition that wasn't enabled.
I would say the 3 combinators mentioned above are for "Reading the inserter count" (arithmetic), "Accruing the total inserter count" (decider) and "Resetting the cycle" (decider). I should probably make a tutorial of this some time...

In any case, now it works and I simply need to recreate all my 50 trains stops one by one...

Good job figuring it out from that screenshot.
The memory cell is a variant of XKnight's design. A tutorial would make it seem less like dark combinator magic.

[Nilaus]

Good job figuring it out from that screenshot.
The memory cell is a variant of XKnight's design. A tutorial would make it seem less like dark combinator magic.

I couldn't help myself, so I created a tutorial for the basic setup of the LTN mod. Considering I spent the better part of an evening trying to figure it out then I figured this could help someone else as well (and I didn't find any other video tutorials on LTN). I hope this does it justice.

https://www.youtube.com/watch?v=dOlmUKlscWs
I expect to create at least one more for the advanced filtered load/unload you mentioned above. Though that may help to dispel the "black magic part of it"

PS. what is it with German speaking mod makers... my favourite mods are created by German speaking modders (+Optera, +YuokiTani, +Arch666Angel)

[Optera]

Good job figuring it out from that screenshot.
The memory cell is a variant of XKnight's design. A tutorial would make it seem less like dark combinator magic.

I couldn't help myself, so I created a tutorial for the basic setup of the LTN mod. Considering I spent the better part of an evening trying to figure it out then I figured this could help someone else as well (and I didn't find any other video tutorials on LTN). I hope this does it justice.

https://www.youtube.com/watch?v=dOlmUKlscWs
I expect to create at least one more for the advanced filtered load/unload you mentioned above. Though that may help to dispel the "black magic part of it"

PS. what is it with German speaking mod makers... my favourite mods are created by German speaking modders (+Optera, +YuokiTani, +Arch666Angel)

German Ingenuity? Although I'm Austrian not German.

Nice tutorial, you have a calm voice making it pleasant to watch it. A lot of youtubers scream or start to talk very fast (like I do myself)
Seems like i never made the analogy of depot = roboport clear in my my description.
2 mistakes I noticed:
Inputs do accept both wire colors. (due to how i merge the two wire signals green is using slightly less processing time so it should be the preferred color)
You set the min delivery size to -1k which is ignored and replaced by default 1k from config.lua, that's why it worked even with an invalid setting.

Advanced guide could include train composition signals and how to use them. Stations become incredibly versatile when you know at what position which type of carriage is. For me it mostly eliminates the need of using min/max length.

For the expert guide try explaining this puppy: viewtopic.php?f=97&t=36976&start=220#p242609
Well I guess XKnight could do it in 3 combinators or less

PS: Before you ask, yes the encoding of signals like i do for train composition is also his idea.

[steinio]

Hello,

would you like to add output signals for amount of free and overall registered trains like a roboport can output?

Greetings steinio

[Optera]

would you like to add output signals for amount of free and overall registered trains like a roboport can output?

Is there any useful application for those stats?
For roboports those stats are often of limited use as you can't make bots spread through the network evenly. I usually end up with the roboport next my bot production so full with one bot type I can't add more of the other.

Trains cant even automatically be put on track. Would be kind of fun though to watch a 4x4 train assembler spewing out long trains like OTTD depots.

Just to hook up smart display, you can also count the blue signals generated by depots. Unless you use stackers ofc

[justarandomgeek]

Trains cant even automatically be put on track. Would be kind of fun though to watch a 4x4 train assembler spewing out long trains like OTTD depots.

Train-deployer/train-assembler has been on my project list for some time, I just haven't come up with a sufficiently good in game mechanic for it...

[NiftyManiac]

Trains cant even automatically be put on track. Would be kind of fun though to watch a 4x4 train assembler spewing out long trains like OTTD depots.

Train-deployer/train-assembler has been on my project list for some time, I just haven't come up with a sufficiently good in game mechanic for it...

I've started playing with something for this; I'll need it for Grey Goo Mk II. The problem with a depot is that I haven't thought of a good way of specifying info for it. Sure you could have a combinator with a bunch of locomotive and wagon signals, but that's just ugly. I've been thinking along the lines of a deployer building the length of a carriage that you place next to a set of rails. If you feed it a carriage, it deploys it (and sends it to the nearest station if the train is complete).

[Optera]

Trains cant even automatically be put on track. Would be kind of fun though to watch a 4x4 train assembler spewing out long trains like OTTD depots.

Train-deployer/train-assembler has been on my project list for some time, I just haven't come up with a sufficiently good in game mechanic for it...

I've started playing with something for this; I'll need it for Grey Goo Mk II. The problem with a depot is that I haven't thought of a good way of specifying info for it. Sure you could have a combinator with a bunch of locomotive and wagon signals, but that's just ugly. I've been thinking along the lines of a deployer building the length of a carriage that you place next to a set of rails. If you feed it a carriage, it deploys it (and sends it to the nearest station if the train is complete).

Feeding train composition into the deployer is easy.
Just take a look at the encoded train composition signal I'm using. It provides exact information of what type of carriage is at what position and can be decoded by a single arithmetic combinator in one tick.