Abstract: A system includes a photo beam detector. The photobeam detector senses a presence of an obstruction. The system also includes an apparatus to attach the photo beam detector to the moveable barrier. At least a portion of the photo beam detector is positioned at the moveable barrier such that a movement of the moveable barrier causes a simultaneous rotation of the portion of the photo beam detector. The system also includes a coupler and a controller. The controller is coupled to the photo beam detector via the coupler. The controller is programmed to determine whether the obstruction exists in a pathway of the moveable barrier from input received from the photo beam detector.