Industrial Ethernet Switch Precision Time Synchronization Technology And Its Implementation

Precision time protocol is widely used in the electric power industry,with the industrial Ethernet widely used in industrial control,higher synchronization accuracy for their communications requirements is in need.My thesis uses real-time industrial Ethernet as an object,investigates deeply into the precision time synchronization technology,which has a practical significance in improving real-time Industrial Ethernet.My innovative are as follows:On the foundation of a deep-analysis in precision time synchronization protocol,which includes its network topology,device type,state machine,clock synchronization process and its way to obtain timestamps,we use a switching chip that supports hardware timestamps and transparent clock to get a hardware timestamps scheme and a transparent clock model,and that was achieved.Based on the study of time source stability,ways to obtain timestamps and the influence in Industrial Ethernet clock synchronization accuracy using time value representation,we propose frequency compensation algorithm and Kalman filter algorithm.We have completed the c programming of Ethernet switches precison time protocol based on VxWorks operating system,and we have implemented frequency compensation algorithm and Kalman filter algorithm.Finally,we have achieved the functional software test.