Is there a belt sensor?

[GaryP]

Been playing this for almost a month and I'm totally hooked.
I've also been reading this forum and had to join.

But what I can't figure out how to make sure I have enough of an item on my belt.
Let's say I'm mining ore, and I have 6 drills going, then off to the smelters to make iron plates. The belt is split over 6 other belts that go different places but the amount of iron plates on each belt differs because of the amount of time it takes for the individual factories to process it. So some belts are stuffed and some are empty.

I have most of my research finished so I have circuits but what I'm looking for is a way to tell if a belt is empty or full.
I've seen timers and such. Any good way to do this? thanks ahead of time for any and all help.

[sillyfly]

There is no such thing yet, but I believe it is planned for future versions.

[MalcolmCooks]

You can do this with using smart chest buffers. It's a bit problematic because you will need several chests and inserters to be able to fully saturate a belt, so I would only do this for relatively low-yeild belts, where the items are being taken off pretty slowly. Here's such a buffer that I've used at a coal power plant:

factorio-160315-002.PNG (1.41 MiB) Viewed 5019 times

The idea is that when the belt ahead of the buffer is saturated, the coal begins to build up inside the smart chests, which sends a signal up the line to smart inserters which stop putting the coal on the belt. Then when the chests empty to below that threshold, the smart inserters begin working again and send more coal down the belt. This is successful in keeping the belt behind the buffer from becoming saturated. However, you need to consider the travel time of items down the belt to the buffer and make sure the threshold is set high enough that the belt won't become too empty before the items arrive there. Also, this is not really suitable for high-yeild belts because it takes many fast inserters to fill them to capacity.
In your case you would have to use smart inserters instead of splitters.

[GaryP]

@MalcolmCooks. I see! You test the belts on the receiving end, not the sending end.
The 2 inserters in the middle are taking coal off the belt and into the 2 crates, and the others are taking the coal out of the crate.
So you monitor the count inside the crate because the 2 outer inserters will auto-stop if they can't place coal on a belt, thereby making the crate fill up. More in, none out.
That's your sensor. I like it. I'm off to try this.

[MalcolmCooks]

Exactly Although I do think it's a nifty trick I have found it's of limited practical use. I just have an aversion to belts building up because, especially on long belts, the amount of items that are sitting there unused is too high for me

[GaryP]

Here's something I've put together on lunch to learn and test this.
I hope I've done it right. With a bit of Photoshop to show all the panels, I can show this. This is truly cool!!!

The smart chest is wired up to the decider combinator which is set to iron plate < 500. If the amount in the chest falls below 500, a Zero signal is output (1), to the 5 smart inserters that only turn on if the circuit network condition is Zero = 1. The lamp is set the same way.
It seems to work nicely because I have an excess of 50 or so plates that were the result of the time it took to turn off the inserters.

[MalcolmCooks]

You'll also see a difference in the way it behaves if you put the smarts at the furnace inputs instead. Since the furnaces will build up a few plates on the output, in the configuration you have here you will see it reacts very quickly to switching on and off, but will have an increased output when switching as there are a few plates stored inside the furnaces. Alternatively, putting the smarts on the input means it reacts slower to change, while the furnaces burn through the ore they have stacked up inside, but the output is more constant.

[GaryP]

Yeah, I see that.
Tonight I'll mess with this in my game. bet I can use it to make a furnace multi use between ores.

[DOSorDIE]

Here the Link to a Multismelter that can smelt all resources.
viewtopic.php?f=8&t=6008&hilit=multi+or ... 70#p124054

[Neotix]

If you want sensor, look at this mod viewtopic.php?f=91&t=14824&hilit=smarter+circuit