A system for controlling access to a restricted-access area in a building has a sliding door system and a controller for the sliding door system. The sliding door system has a door frame and a sliding door which can be moved in the door frame between a closed position and an open position by a drive unit. The door frame has a passage region and a wall shell region which at least partially accommodates the sliding door in the open position. A controller is arranged on the sliding door and is communicatively connected to the drive device. The controller is designed to control a movement of the sliding door between the closed position and an open position. A light projection device is arranged in an interior of the sliding door and is communicatively connected to the controller. The light projection device is designed to project status information specified by the controller for a user requesting access to the restricted-access area as a visible light projection onto a projection surface.