Oh, this "zero signal is no signal" is so painful for me. I want my supply train to depart from station if one cargo type is fully unloaded by circuit network signal. I just don't get how to do it. My head don't work that way( And there is already nearly ten combinators to call train to s...

Oh, this "zero signal is no signal" is so painful for me. I want my supply train to depart from station if one cargo type is fully unloaded by circuit network signal. I just don't get how to do it. My head don't work that way( And there is already nearly ten combinators to call train to st...