Network access control system is through the electronic identification devices (such as magnetic card, radio frequency card) or biometric means (such as voice, iris, fingerprint) to identify the identity of those who want to open the door, and
set permissions based on pre-decision to open the door or alarm signal. Access control system to use more common RS-485 bus, to achieve communication between control hosts and identification devices. This connection, each identification
device special wiring needed to connect to the control computer, a construction difficult, expensive, difficult to meet
the network anytime, anywhere access and control the times demand, adopt Ethernet as the communication channel between control hosts and identification device, using TCP/IP network traffic patterns, and easy to implement communication between access control host and the embedded controller, wiring simple, low cost, post-maintenance more convenient.