Photocell systems are detectors used to prevent the barrier systems from hitting any object within the operating distance. Photocells are used in barrier systems, arm barriers, sliding door motors, mushroom barriers, road blockers and all kinds of automatic access control systems. mounted and used as a photocell set. If the vehicle or any object enters between this set of photocells, the barrier stops its closing direction or its movement in the opening direction according to the barrier's characteristics. or when the object is pulled in front of the photocells, the barrier completes the reclosing movement. While mounting the Photocell Barrier, it is necessary to consider the sunrise and sunset directions. When photocells are exposed to excessive sun rays, they can perceive the sun's rays as an object. If the place where we are going to install it coincides with the sun's rays, it is necessary to block the sun rays by making a canopy over the photocell. Photocells are indispensable elements of barrier systems.