In today's increasingly widespread use of IC cards, IC card access control systems have gradually replaced other existing types of door locks with their access control management, which is safe, reliable, efficient, flexible and convenient, and has become the mainstream of current access control systems. Shanghai Automatic Doors Xiaobian today will share with you the characteristics of IC access cards.
The main hard device of the access control system consists of a computer as a management computer (also known as a master computer) and a number of sub-control computers (also known as sub-control modules). The sub-control module is responsible for reading the card (ie identifying the entry key), opening the door, closing the door and logging in for each controlled door. The main control computer is responsible for the initialization and working mode setting of each access control subsystem (such as delay time, etc.), as well as the management of resetting system data and obtaining login information of each access control subsystem. This article describes the characteristics of the system.
To design an access control system, the first thing to consider is system security, that is, whether it can effectively control the access of personnel and master the information of its access. Because the IC card access control system is an intelligent electronic control system, it can make full use of the "smart" of the computer, and at the same time use a variety of means to control to ensure the system is safe and reliable. The simplest and most effective of these are the following.
First, the password is set by the password set in the IC encryption card. If the password is not correct after several times (usually three times), the card will be automatically burned and cannot be used. This can effectively prevent malicious verification of theft of user information.
The second is to use the user permission table in the system to re-authenticate whether the cardholder can enter the door.
Third, the effective use period is set on each IC card. If the IC card exceeds the validity period, all the data of the user will be automatically deleted from the access control subsystem control module, and the card is invalid.
Can be considered from two aspects of software and hardware.
The reliability of the hardware, in addition to the mechanical components such as the electronically controlled lock, mainly considers the production and selection of the sub-control module, because it has to work 24 hours a day, so its performance requirements are high, it should be able to meet the environment. Changes in temperature, humidity, and resistance to electromagnetic interference.
If the Newton 7000 series module is selected as the sub-control module, because this module has a strong adaptive function, it can automatically adjust the signals of different baud rates, as well as various protection circuits, etc., which can ensure the needs of low-level management work. .
The reliability of software design mainly considers the acquisition and maintenance of various state information, whether the design of the communication protocol is standardized, whether the processing of various special cases is reasonable, and so on. For example, in order to ensure accurate communication between the master computer and the child control module, an automatic retransmission error correction mechanism can be adopted to effectively eliminate signal conflicts that may occur when the access control subsystem and the management computer are working in the network at the same time.
Since the setting and management of all data information in the system is completed by communication between the host computer and the sub-control module. Managers can freely set passwords, user permissions, door lock delays, etc. according to their needs.
At the same time, the main control computer and the sub-control module work independently at the same time. Only when the initial data in the sub-control module is set, the data in the sub-control module is modified, and the information recorded in the sub-control module is acquired, the two need to communicate with each other. , exchange information. This design approach gives the system a lot of flexibility.
In order to reduce the hardware cost, a sub-control module can be designed to control multiple gates at the same time. For example, when using the I-7188 as a sub-control module, one sub-control module can control three gates at the same time. In fact, this configuration is equivalent to one. A macro parallel processing mechanism.
The user permission table can be arbitrarily set by the administrator, and it is very flexible to use, and it is easy to meet different requirements such as "one door one card", "one door multi card", "multiple door one card".
The needs of users are constantly changing, and there should be some room for designing the system to ensure the dynamic needs of users. For example, each sub-control module in the system has a unique address. When it is necessary to increase the number of controlled gates, just add a corresponding number of sub-control modules and access control subsystems, and assign a unique address to the sub-control modules.