Research On Multi-Protocol Embedded Data Processing

As the Industry 4.0 coming up,the demands of industrial control system in intellectualization,automatization and informatization are becoming higher.Traditional industrial control region is developing towards the direction of personalization constantly.Ethernet and human machine interaction are added into the embedded system devices.These devices are connected with varieties of industrial control buses.More and more personalized control systems will be appeared.Oil Loading System in Oil Refinery(OLSOR)is the project background of this thesis.Data that come from field control instruments can be acquired by OSLOR.According to the data returned,the processing of loading oil is controlled by OLSOR.Thus,OLSOR is consisted of bus control interfaces,data storage modules.In order to implement the data sharing,data can be uploaded to database.Running state of OLSOR also can be monitored by administrator.Thus,OLSOR must have the Ethernet interface.Based on the above requirements,OLSOR needs to implement the data acquisition from different devices(Multiple Protocol: Modbus,UDP.HTTP),data storage function and provided Ethernet function to realize remote monitor and interaction.In order to improve the speed of system response,reduce the burden of system running and improve the flexibility of modules,the task scheduling algorithm is proposed.This algorithm uses object-oriented program concept.Tasks become objects.During the system running,objects that meet the conditions of implementation can be executed by CPU.The communication among objects is based on message mechanism.Data interaction is based on the shared memory.The scheduling algorithm is implemented by main function and interrupt.So that the embedded system without operation system can response in time and realize real-time monitoring.For all of the data acquired,according to different usage,data hierarchical storage is implemented.The real-time data and the data which should be sent to browser are stored in RAM.The historical records and backup data are stored in SD card.Multiple devices' sharing data and data whom time longer than historical records were stored in database.In order to implement the field data monitoring based on B/S architecture,this thesis based on TCP/IP implements HTTP to analyze and respond browser's form.The processing of analysis and response takes up more time for CPU.It is effect on the processing of other tasks.Thus,the method of state machine is proposed.Tasks that takes up more time are divided into varieties of fragments(sub-tasks).The execution time of fragment is shorter.On the basics of guaranteeing the response speed of Web,it can improve the timeliness of system.