Discussed the application of the entrance guard system entrance guard system is in and out of the management system of a subsystem, it usually USES the credit card, password, or human biometrics technology, under the control of the management software, manage the personnel or vehicles inward and outward, people gain acceptance in and out of the car free passage, while for those who shouldn't have access to ban them. So many people need to check the car as to the identity of the space, the entrance guard system has become the indispensable configuration items. This issue is to discuss the technology of access control network communication application. Engineering principle and principle of transmission line engineering of entrance guard system engineering principle and other automatic control system have similar or the principle of intelligent building system, its operation can be divided into three link sensing, management and execution, but it is more compact, more simple. Sensing: card reader, keyboard password, all kinds of biological recognizer, push button, lock state sensor belong to the sensor, the task is to take orders, will signal to upload or upload after check (identifier). Management: the controller and bear the entrance guard system management functions, management software in after receiving the information from the sensors, according to the time, the card number and other information to judge whether to open the door, such as open the door, emit the door command to the electric lock; And after receiving the locked state information, start time, timeout alarm. Execution: electric lock on receipt of the open or close command (power supply or power), the "execution" command will work status to adjust it to the consistent with the command. While electric lock inside the lock state sensors have the effect of the feedback and supervision. Some controller can be used to relay control signal output, to control the camera and lighting of the linkage. Transmission lines By the working principle, the entrance guard system has the following several kinds of transmission lines: the power cord UPS power mostly from room entrance guard system, in order to avoid misoperation during power outage. The power cord, usually in a 220 v ac transfer purpose is to reduce the power of online pressure drop. Next, the controller is equipped with regulated power supply, ac 220 v power transformation into dc 12 v power supply, supply controller and electric lock, respectively. Entrance guard system with electric lock mostly belonging to the 12 v dc power supply. At the instant of the electric lock open circuit, the electric lock line package (electromagnet coil), can produce a strong current in the power cord, it is easy to cause the power fluctuation, and the power supply fluctuation on the stability of the controller work extremely adverse, so the reliability requirement is high in the entrance guard system, controller and electric lock separately using different power supply module, which is 220 v ac power supply to the controller, using two dc 12 v power supply module after each rectifier/voltage regulator, supply electric lock and controller respectively. Selection of all kinds of power cord is essentially based on electrical manual, choose the standard power cord. Controller signal line controller in three groups of signal lines, respectively connected to the card reader, the electric lock lock state of sensors and a push button. This three way signal can be used in the integrated wiring twisted-pair cable replacement. In order to avoid the electromagnetic interference of the space, card reader signal lines should be shielded wire, the other two signal lines, shielded wire can be used, also can use the shielded wire. Remote network signal line From the controller to manage the transmission between the computer, mostly by RS485, distance close available RS232, require fast transfer rate when using TCP/IP protocol. In order to avoid electromagnetic interference, this signal lines should be shielded twisted-pair cable. When the controller needs to use the output hard contact direct control of the hard disk video recorder (video) synchronously with credit card to open the door, this line of (2) appropriate USES shielded wire, so as to avoid because of the hard disk video recorder input signal amplitude was little caused by electromagnetic interference triggered by mistake. But if it is the power of the transmission light directly with hard contact, you should use the power cord. According to the above analysis, the transmission power supply for electric lock, controllers and lighting power supply, should use the power cord, its cross-sectional area can be according to the current generated by the pressure drop and heat calculation, also can check electrical manual for. When transmission sensor signals and control signals, should according to the installation of the card reader and the controller manual, choose the shielded wire or not shielded wire. With entrance guard system to lock the control number more and more, for the safety of network transmission speed and wiring are higher and higher, and engaged in the construction of access control system must also be at the same time the construction of the integrated wiring system, thus using the network twisted-pair cable as transmission line of entrance guard system, has become the entrance guard system cable main choice. According to the analysis of various entrance guard cable, card reader, controller, signal and control line can be used between management computer network twisted-pair cable. At the same time in the case of entrance guard system and integrated wiring, for using TCP/IP protocol of remote network signal lines, is necessarily use twisted-pair transmission, it can use the integrated wiring system standard star structure to realize signal remote transmission. RS485 and RS232 line can also use twisted-pair cable network, according to the principle of entrance guard controller installation, the equipment should be used is shielded twisted-pair cable, so as to avoid electromagnetic interference caused by wrong operation. Integrated wiring network application considerations In the use of integrated wiring system is regarded as the transmission lines of the entrance guard, should pay attention to the following factors: connection method should be completely according to various wiring rules of access control devices, and keep detailed wiring diagram, in order to avoid line judgment in maintenance of pain. Shielded twisted-pair cable shielding layer should be according to the card reader, controllers, complete earthing installation manual. If you are using TCP/IP network is shielded twisted-pair cable transmission, can be completely using shielding integrated wiring system shield end wiring rules. When using TCP/IP protocol, it is best not to with other intelligent system (including the office automation system and other software systems) Shared network switch, so as to avoid conflict transfer agreements on accident. When using the network TCP/IP protocol, entrance guard system management of computer can be regarded as a server in the access network, using twisted-pair cable or optical cable connected to the distribution frame. Integrated wiring system can be used in the entrance guard system, it has been confirmed by supplier and installer of entrance guard system, just should be comprehensive assessment in the project cost, construction and performance, in order to achieve the best effect.