Research On Multicpu Control Synchronization In Distributed Control System

In the21st century, with the rapid development of aerospace engineering、Electronic and Telecommunication Equipment and pharmaceutical industry, the topological structure of the distributed control is widely used in these areas, it makes the whole system had high reliability and stability in production and operation, With more and more high automation level of integration, For some fields which has high requirement of precision, in the control process, they need multiple nodes of the CPUs keep the clock synchronization, namely, the clock with consistency. Therefore, in the distributed control system how to keep more CPUs have the clock synchronization becomes a very important technology.Messages transfer from one CPU to another one, because of the delay of the transmission process, CPUs are not consistent in distributed control system, the clock synchronization problem can be solved by measuring the corresponding proper compensation in transmission process. In all kinds of control system in the modern industry, precision clock synchronization protocol PTP is highly applied, it measures the accurate delay in the telecommunication lines by software.This paper briefly introduces the basic structure of distributed welded pipe control system, and it indicates the necessity of application of the clock synchronization in the distributed control system. It discusses several clock synchronization protocols in modern industry, and it analysis the comparison NTP protocol and PTP protocol from synchronization mechanisms, characteristics and modes, it points out the superiority of the synchronization of IEEE1588in the industrial communication; it constructs the CPU clock synchronization tests platform experiment system, it makes two TMS320F2812respectively as the node of master clock and the node of slave clock, they communicate by the CAN bus, it uses the software DSP/BIOS which is of CCS of development environment of DSP to design, it test the feasibility and reliability of IEEE1588clock synchronization protocol, Analysis the influence factors of the major of precision time synchronization, a detailed study of the crystals stability, the influence of accuracy of time synchronization, after repeated welding experiments proves IEEE1588synchronization protocol can satisfy the clock synchronization of more modules, the error of clock synchronization is in the acceptable range.