1. Main functions and features:
1) Three digits are to show the available lots number and the arrow is to show the direction.
2) The LED indoor screen will be installed at the crossing of the carport.
3) The outdoor let screen will be installed at the entrance of car park or other outside places.

2 How parking guidance system works:
Firstly, UD 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 message to CCU; CCU processes these data and sends the relevant command to ZCU and LED panel