Parameter: Size: dia. 100*23(mm) Weight: 113g Principle: Ultrasonic Work temperature: -20~+80°C Voltage rating: DC 24V Current rating: 13mA+17mA(LED indicator) Detecting area(3.5m): 0.4sq.m Detecting arrange: 0.1~3.5m Baud velocity: 4800bps, N,8,1 Communication: RS-485 Available distance: ≤1000m Function: 1).ultrasonic detector as one of the main part of parking guidance system makes use of ultrasonic detecting the parking space to get message and transfer to ZCU or other equipments by RS485. 2). One parking space needs one UD which is installed in the middle of the car park space. How Parking Guidance System Works: Firstly, Ultrasonic Detector takes use of ultrasonic wave to detect the car space to see if it is occupied by vehicles and transfer relative command to LED Indicator which will turn from green to RED when occupied, or it will keep GREEN; meanwhile, the UD transmit its status message to ZCU immediately, and ZCU will collect and forward the information to CCU; CCU processes these data and sends the relevant command to ZCU and LED pane.