If you are entering B security from the public area you will walk passed gates B10-B13 which are Schengen gates. Passengers for non-Schengen B gates will go through passport control (one way only Schengen > non-Schengen) after B13. If you are going to A you turn right before passport control, go down the elevator (or stairs), walk through the tunnel and up at the other end. There is no passport control or further security.