Access Control System Home Burglar Alarm Analysis

The access control is a control network system consisting of a controller, an information collector, and an electronic control lock with a CPU processor as a core, and reads the information through the system. Processing, automatic control of various door lock switches. According to the way of information reading can be divided into: card, induction, image recognition, eye iris recognition and so on. Their technological content and order of system cost increase in turn. Stand-alone access control is non-network type. Each door lock is independent, its information is usually read card and induction type, the advantage is low cost. This article does not specifically analyze the independent access control, focusing on the analysis of network access control systems. The network access control system consists of a controller, a card reader and an electronically controlled lock. The door opening button and other components are the bottom layer of system integration and the execution layer. (1) Controller: It is used to collect the information from the reader to process, issue instructions, control the opening of the electronic control lock, store the data of the sensor card, complete the bus networking function, etc. (2) Card reader: Read the information on the proximity card and upload it to the controller. It can be specially equipped or optional, as long as it meets the requirements of the interface; the installation position is close to the door. (3) Proximity Card: An IC or ID card used to store personal information. It contains an integrated circuit and an induction coil. When the proximity card is close to the reader, the information stored in the proximity card is transmitted to the card reader in an inductive manner to achieve the purpose of opening the door. (4) Electronically controlled locks: Actuators for access control to control the "open" and "closed" states of the gates. The installation location is on the door frame or the door leaf in the room. (5) Open the door button: It is the switch that the person in the room opens the door, the installation position is in the close place of the door in the room. Currently on the market, there is one control, one control, one control, four, etc., that is, one controller, control four doors, each door is equipped with a card reader, an electronically controlled lock, a Open the door in the room.

The working process of the system is: After the proximity card is authorized, the proximity card reader approaches the card reader, and the information is transmitted to the controller. After the CPU of the controller compares the data from the card reader with the data in the memory, it will appear three times. Possible results. First, the data transmitted is generated by an authorized card. The card reading time is the period of time allowed to open the door. When these two conditions are satisfied at the same time, an instruction is issued to the lock, the electronic lock is opened, and an acoustic or light prompt is generated. Second, when data is sent from an unauthorized card, or if it is not open, the electronic lock will not be issued instructions, the card will be invalid, and the door cannot be opened. If someone's proximity card is lost, the winner cannot enter illegally during non-working hours. Third, when the security guards read the card, the system program records once, but the electronic control lock does not work and is displayed on the patrol management terminal, which is convenient for the attendant to keep track of the patrol personnel. If you need to come out from the room, press the door open button switch, the controller sends a command to the electronic lock after receiving the message, and the electronic lock opens. The door closer automatically closes the door leaf. The function settings of the access control system are performed on the PC workstation as a desktop. These functions include opening door closing time period setting, proximity card authorization, corresponding setting of card number and controlled door, attendance statistics report, setting of patrolling card number. By modifying the program, linkage between the access control system and other systems can be achieved. The network administrator has the right to open any door on the workstation.

A network access control system is composed of a number of door controllers, and each door control unit is connected with an access control network controller via an RS485 bus to form an access control network system. The network is connected to the computer local area network through the Ethernet bus to form a three-level system integration and a three-tier network structure that can be managed from the top down. The lower layer network can be controlled by the upper layer management and independent of the upper layer. When the upper layer fails or disconnects, it will not affect the normal operation of the lower layer. In this way, both the degree of intelligence in network access management and the reliability of each controller can be improved.