Arrows seems to appear on the 5th candle. I'm using "<1000" as a condition because when there is no arrow, the buffer gives us a value of 2147483647, so the moment when the arrow appears is the moment when it's buffer value is less than 2147483647. Well, 1000 looks better than 2147483647 and that's why I'm using it.
"Signals" block is waiting for the condition (inticator<1000) to happen to pass once, and then waits for the opposite condition (indicator>1000) to happen. After the opposite condition happens, it starts to wait again for the normal condition.
dr_hassan , just to mention that I saw your project where you trying to do it, and I think you can make it, but check the link I posted above.