Research And Development Of Embedded Network Clock Based On Network Time Protocol

With the development of automatic technology of electric system, the need of clock synchronization's precision is more and more exigent, the electric system is trending to networklize,for example, the digital transformer substation. But traditional clock synchronization method existing compares time singly, it can't synchronize the time of the entire electric system's devices. So, this thesis has developed an embedded network synchronization clock based on NTP, which is used for network time synchronization and traditional time comparing. This clock can provide precise time for automatic device of electric system such as PC malfunction to record wave and event.This thesis starts from how to implement the clock synchronization, on the base of studies of existing network synchronization protocols, and develops an embedded network synchronization clock based on NTP, implementing the function of network time synchronization in LAN using NTP.Specifically, this thesis includes the following aspects:This thesis has lucubrated existing network clock protocols, mainly analyzing the NTP protocols'working principles and message format, combining the practice of electric system, putting forward the time comparing precision of this design.This thesis has proposed a designing schema of embedded network synchronization clock based on NTP, having done the entire development of hardware and software system. The system is based on the core of Rabbit 2000 micro processor, and implementing the NTP network time synchronization function, providing pulse time comparing signal and serial-port time comparing signal. The software is developed using Dynamic C. Bring forward a scheme that can identify a time less than a second, and then we can get the exact time when the NTP synchronous messages arrive at the node and leave.This thesis has used Delphi to write the client time comparing program to test the embedded NTP network synchronization clock, the test results indicate that the network clock of this paper has high precision, convenient to use, and has great value in practice.