First, the concept
The access control system, also known as the entrance and exit control system, is a system that manages and controls the entrances and exits of important areas or passages. With the development of society, it is not limited to the simple management of door locks or keys, but a new modern safety management system that integrates automatic identification technology and modern management technology, and has become an extremely important part of the security system. It is widely used in smart buildings, offices, hotels and other occasions. At present, the control methods of the access control system mainly include: fingerprint recognition, face recognition, iris recognition and RF card. The first three methods belong to biometric technology. They are the identification carrier and means of the characteristics of a certain part of the human body. Their uniqueness and non-replicability determine that they are the safest method of identity verification, but they are expensive and difficult to popularize. Personal privacy is involved only in high-end and absolute secret locations.
The RF card is a combination of wireless RF technology and smart card technology. It is easy to use and easy to maintain.
In order to improve the modern management and remote monitoring capabilities of the access control system, an access control system based on Web technology is introduced. The system adopts wireless radio frequency technology. When a non-contact IC card appears in the RF range of the reader, the card is read and the information is transmitted to the server through the serial port communication for related data processing, and a management platform based on the C/S mode is constructed. The administrator can query and control the access controller through the web page, thereby effectively realizing real-time monitoring of information at any position on the Internet.
Second, the system architecture
The system uses a non-contact IC card and uses RFID (Radio Frequency Measurement) to detect the IC card. When the IC card is close to the reader, the reader can accurately identify it and send its serial number to the master. And the PC, the application database is connected to the background database to obtain the user information corresponding to the card number.
If the card has been registered, the controller is verified and notified to open the door, and the card number and the door opening time are recorded. Otherwise, the passage is prohibited and the cardholder is notified to leave.
The system consists of five parts: electronic tag, reader, serial communication, server and user terminal. As shown in Figure 1. The reader is the core of the system. It communicates with the IC card (electronic tag) through the RF signal to complete the work of reading, storing and transmitting data. It can work independently or network. The RS232 serial communication is used to connect to the server. .
The C/S structure is adopted between the server and the client, and the application software is connected with the database SQLSERVER2000 through the ADO object, and the two are interconnected through the local area network. In the case that the system administrator grants the authority, the user can query, count, and print all relevant records of the management system.
Third, the hardware design
3.1 overall hardware design
The RF reader is the core of the system. It consists of the main control circuit, RF read/write circuit, antenna coupling circuit and antenna. It is responsible for the processing of RF signals and the transmission of data, and completes the task of reading the serial number of the IC card. as shown in picture 2.
The electronic tag, that is, the RF card, consists of an IC card and an inductive antenna, and is packaged in a standard PVC card. The chip and its antenna have no exposed parts. The card does not need a power supply, and when it is close to the reader within a certain range, the data is read and written by the transmission of the antenna. This article selects Philips' Mifare1 card, which is based on ISOTYPEA international standard. Each card has a unique serial number in the world, and I heard about the access controller. With anti-collision function.
Lift Elevator,Mrl Passenger Lift,Goods Passenger Lifts,Vvvf Drive Passenger Elevator
XI'AN TYPICAL ELEVATOR CO., LTD , https://www.chinaxiantypical.com