Access control systems, in the field of intelligent building, meaning Access Control System, referred to as the ACS. Means "door" ban authority is the "door" alert precautions. Here the "door", a broad sense, including the ability to access a variety of channels, including doors, vehicle access door Passage and the like. Therefore, access to include a vehicle access. In the yard management applications, vehicle access control is an important means of vehicle management, not to charge parking fees for the main purpose is to manage vehicle access privileges.
　　Entrance access control security management system is a new type of modern safety management system, which combines computer automatic identification technology and modern safety measures as a whole, it involves a lot of new technology in electronics, machinery, optics, computer technology, communications technology, biotechnology and so on. It is an effective measure to solve the important sectors entrance implement security management. For a variety of confidential sectors, such as banks, hotels, parking lots management, computer room, armory, confidential room, office, intelligence community, factories and so on.
　　Access control system goes beyond the mere doorway and key management, it has evolved into a complete access control system. It plays a large role in the work environment, safety, personnel attendance management and other administrative work.
　　Network access control is first appeared in the late nineties. With access control systems increasingly wide range of applications, people demand access control systems access control is no longer limited to a single, but asking them to also have access control, time and attendance management, building automation and other control functions, and system integration and remote control functions have been very clear demands. However, the traditional access control based on RS485 communication, transmission distance and the number of nodes are limited, it can not be achieved remote control and intelligent management. Ethernet-based transmission of network access control came into being, it will not only solve the problem of long-distance transport, in the management, but also to more servers, participating stations as possible, so as to provide multi-level, multi-module access management.　
　　Comply with the application requirements change, many vendors have launched network access control access control products. The so-called network access refers to the data transmission based on TCP / IP protocol access control systems, the control center servers and front-end controller using the network structure, management systems between the servers and workstations (PC) are also data transfer via network .