The node controller serves as a link between the upper and lower parts of the ultrasonic parking space guidance system. It is connected to the host computer in the upstream direction and uploads the collected data to the host computer. The node controller is connected to the ultrasonic parking space detector and the parking space guidance screen in the downstream direction to supply power to the ultrasonic parking space detector and collect data. Parking space occupancy information, mounted on the parking space guidance screen, displays parking space occupancy information in each area.