factorio how do u use combinators?

[ClaptrapCL4PTP]

Been watch videos and reading online but nobody is making any sense how to use cominatoirs. ANy help would be nice

[fractalgem]

Before I try to help you understand them, a couple questions:

1. do you know how to use the circuit network without combinators.
2. Are you familiar with boolean logic (aka Given that P is true, Q is false, and R is True, you can conclude: P AND Q=false, P AND R=true, P OR Q=True, p XOR R=false)
3. are you familiar with functions, e.g F(x)=3x?

[fractalgem]

...i'm going to assume the answer is "no".

By taking some red wire and connecting a chest and an inserter, you can tell the inserter to only run if there's, say, less than 20 circuits in the chest; assuming the circuit is taking from the belt, this means the overall system is "attempt to keep 20 circuits in the chest but not more than that".

Alternatively, you can have an inserter set to only take circuits if there's at least 15 in the chest, perhaps because you want a different assembler to have priority for receiving circuits.

However, there's only so much complexity you can get with just the wires. They'll do for almost everything in vanilla, though. Still...

Say you want a pump to only run if there's at least twice as much petroleum as heavy oil

So for this, we need at least an arithmetic combinator. Wire the input side of it to a heavy oil tank. Set it to multiplication, and use a constant of 2. Set the input channel to heavy oil. Select whatever output channel you want; using the non-item channels is recommended but not required (you can even use heavy oil as the output, but you'd better be sure not to let the input connect with the output if you do so, or you'll get Recursion...which *can* be useful, but it's not what you want in this situation.)

What this is doing is the function f(x)=2x.

Hook some wires up to the petroleum.
Now we have "Petroleum" as a value, and "2*heavy oil" as a value thanks to the arithmetic combinator. Since the only remaining condition is comparing them to eachother (e.g. 2*heavyoil>petroleum), we can let the pump do the comparison. However...maybe this isn't *quite* good enough for you, since it won't run if 2heavyoil=petroleum.

So...we use the logic combinators. We'll need 2 of them.

The first logic combinator does the same thing as the pump used to do; it checks if 2heavyoil>petroleum. It will output a value of 1 (true) if this condition is met.

The second logic combinator compares the two and sees if 2 heavy oil>petroleum. It will output a value of 1 (true) if this condition is met.


Now, we want the pump to run if any of these conditions are met, so we want the "logical OR" operation. Luckily, this is a fairly simple operation: have all logic combinators output to the same channel and have the pump check if the channel is > 0.



More complicated things can be done if you understand logic gates.

I hope that helps?

[KatherineOfSky]

OP, I have a short tutorial with examples and pics in my guide on steam. Look under "Usages of the Logic System" and the subsequent header.

http://steamcommunity.com/sharedfiles/filedetails/?id=661582295

[Ultra]

I have played this game for over 250 hours. Honestly I have never learned how to use combinators. I can use basic red and green wire signals but that is about it. The thing is that knowledge is enough. I have never understood why we need super advanced combinators. You can build a mega base without them just fine. The only place where the circuit network is really mandatory is when you deal with oil cracking even then you just need basic wires.
I feel that combinators are just there for people who are really into that thing.
I can promise you your factory will work fine even without combinators

[fractalgem]

Originally posted by Ultra:

I have played this game for over 250 hours. Honestly I have never learned how to use combinators. I can use basic red and green wire signals but that is about it. The thing is that knowledge is enough. I have never understood why we need super advanced combinators. You can build a mega base without them just fine. The only place where the circuit network is really mandatory is when you deal with oil cracking even then you just need basic wires.
I feel that combinators are just there for people who are really into that thing.
I can promise you your factory will work fine even without combinators

While it's true they're not needed in vanilla, they do become somewhat more useful when dealing with modded factorio, especially some of the nuclear reactor mods (e.g. if the reactor scrammed, you have to forcibly cool it all the way down).

They're also not that complicated if you understand boolean logic and algebra.

[<unknown>]

With combinator you can build a factory build-on-demand very cool to do.

http://steamcommunity.com/sharedfiles/filedetails/?id=847773160

This example is not fast because it need more gear assembly.

[!?!]

If you want a lamp to turn red if a coal chest is empty, link the chest to a decider combinator, set it to if coal<1 output red signal=1 and connect the decider to a lamp with colored light enabled.