1. two-stage control: CAN bus; RS-485 bus 2.Communication protocol can be supplied 3. 3968 slot can be controlled 4. low cost

As following systematic topological graph:

      The system is comprised by two-stage bus network: the first stage is CAN bus network, which combine data processing terminal and every slots collection terminal, realizing the function of transmitting all kinds of real-time data in parking lots with high-speed, high reliability and stability; the second stage is RS-485 network, which connect ultrasonic sensor above the car slots and slots display into one bus network, and connect to relevant car slots controller, coming true the function of data statistics and distribution in whole parking lots. The using of CAN bus network ensure data transmission instantly and unfailingly, while the using of RS-485 network pursue low cost of system and easier to install.  

       By the ultrasonic sensor installed above the car slots, the information of car slots can be collected real time. The slots controller connecting to sensor will collect the data of every sensors as polling mode, and transmit the data to data centre by CAN bus network. The data centre will handle all data. And then centre will transmit the processed slots data to every LED display in parking lots, which will show the empty slots information and guide the vehicle into empty slots. Meanwhile, the system will transmit data to computer, which will store the data into database server. Users can check real time information in parking lots and statistical data of every year, month, day and hour by computer terminal.

Unique Features of System

1.1.         Simple System Architecture

The system architecture is simple, just using CAN and RS-485 two-stage bus network, which are widely used in market. This architecture reduce the system construction difficulty and bus time delay. Using CAN and RS-485 two kind of bus network at the same time, with two ways transmission, long distance and high stability, CAN bus perfectly realize high dependability and large-scale coverage; with low cost and generality, RS-485 bus effectively decrease system construction cost and construction difficulty.

1.2.             Easier to Arrange the cables

Using DC 12V power supply for every terminal, every partition’s LED screen can connect to any line of RS-485 bus linked to any one slots controller. So which will decrease the difficulty to lay the system cables. Buying one line 4 cores cable, you can resolve the system cable laying challenge.

1.3.             More Car Slots Can be Controlled

The system can joint maximum 63 units of terminal (PGS-320), which include one data centre and 62pcs collection terminal (the 0# is data centre acquiescently, and the 63# is broadcast address with no use.). Everyone collection terminal maximally can supply 4 lines of slots ultrasonic detector collection bus, and every line bus can maximally link 16units of ultrasonic detector, that is every collection terminal can maximally concatenate 64 units of slots detector. So the total max 3,968 units of car slots can be controlled by whole system.

1.4.             Flexible and Simple Partition

This system can maximally manage 58 partitions(including Physical Partition and Logical Partition), which can be designed flexibly and include multiple. Every logical partition include multiple physical partition; every physical partition can be only one line RS-485 collection terminal bus and also can be multiple lines of RS-485 bus, which can connect to different collection terminal(PGS-320).

1.5.             Easier to install Parking Screen

The slots display in every partition can connect to anyone line RS-485 bus; 8pcs of LED screen can be connected to every line RS-485 displaying different partitions’ information. The address of screen and partition No. are one-to-one correspondence.

1.6.             Work offline and Independently

After system configuration, it can work offline out of computer.

System Configuration

PC Management Software

Application Environment and Language Supporting

Software environment

       Windows OS: Windows 2000/ XP

Hardware environment

       CPU: P III 500 MHz or above

       RAM: 128M or above

       Video card: standard VGA,24 bit true color

       Other:  CD-ROM,mouse,serial port

Serial port parameters

       Baud rate: 9600

       Start bit: 1bit

       Data bit: 8bit

       Parity bit: null

       Stop bit: 2bit

Language support: Simplified Chinese ,Traditional Chinese, English

Application Program Interface

Parking Guidance System