Factorio Forums

I build and want to share a small setup which stops belts when a wrong item is on the belt:

1) Belt are all connected per green and red wire, green wire going to input of an aritmetic combinator, red connected to output of the combinator
2) Constant combinator connected per red wire to the output of the artimetic combinator output
(3 red wire to powerpole was only for testing and seeing the signal going out and is not needed)


Settign of artimetic combinator

it outputs the amount of items which arent in this case "Iron Plates" so it will emit a red signal if a wrong item is on the belt

Setting of the Static combinator:
Sending a Dummy RED Signal with the Value 1 cause we cant ask for 0 signals in conditions


Settings of the Belts:

they read the output and on same time only work if RED Signal is 1 (the dummy value from the static combinator, could be any value which is set on the static combinator, dont need to be one)


Have fun with this build could be handy in some spots

Greetings Ralle

I like logic circuits and this is really nice.

you can allow passage of any items you want (not just one type as in this case). and without using a math combinator.

one wire from constant to belts, belts output data the same way, but their enable condititon is everything < 0
The constant combinatior set Iron = -100 (and if you want coal to pass through also, set to coal -100 also and so on).

The belts will add their contents to the negative signal, and anything that's not to a negative by the constants will push its signal over 0, stopping the belt.
You can even set something to -1 on constant so that 1 of it mixed in with iron will pass through, but 2 or more on belt at same time will stop the belt.

And then pick out the unwanted items with filter inserter. Should work with power loss, too. Nice.