The level crossing mechanism is controlled from the main control screen via an Arduino. This senses the limit switches and stops the motor at the correct point. It also set the direction of the motor to close or open. It is necessary for this to be operated from the main control screen as the main computer then knows whether it is possible for the train to cross, and can act accordingly.

The left hand image below shows the under bench mechanism with the motor and limit switches. These are operated by an arm atteched to the motor shaft. There are two of these mechanisms, one for each gate. The right hand image shows the Arduino and circuit boards towards the top of that image. (The lower board is for controlling lighting which is something the same Arduino can do.)