Help with circuit network

[mattshawman]

I've just started playing and I'm struggling to get my head around various aspects of the circuit network.

I want to know if it is possible to connect various inserters to start inserting iron into an assembly machine when the number of an item on a belt drops below a certain level.

Any help would be greatly appreciated, Thanks!

[Caine]

Connect a wire from a piece of belt to an inserter. Set the belt to read belt contents and set the appropriate condition on the inserter.

If you need to monitor a longer belt segment, then you can utilize a counter and make two of those read belt content sections at the start and the end.
Have the start increment and the end decrement (arithmetic combinator * -1).

[mattshawman]

Thanks for your help!

[Termak]

Just remember to set the read belt to "hold" the signal, its on pulse by default.

[Caine]

Pulse with a counter, hold without one.