Research On Application Control Platform Of Soft PLC Based On XML Language

Now,the soft PLC has been widely used in industrial control field.The development system of soft PLC has the advantages of multiple programming languages and rich functions.This is beneficial to application developer.But it also has some disadvantages such as high professional requirements,expensive license fee and larger memory footprint.All of these problems make the development system is not beneficial for equipment operator to use in such situation as frequent modification and online debugging.Therefore,developing a dedicated tool for operators for editing and debugging control programs will be of great importance to improve control program development efficiency,reduce the investment in hardware and software and reduce the cost of employment.Based on research about structure and operation principle of the hardware and software PLC and the usage requirement of end-user,this paper design a new control model by combining extensible markup language and related parsing techniques,Ethernet communication technology and serialization and deserialization mechanism.By combining the grammar of XML,PLC basic control instruction library and requirements of machine vision,this paper finishes the instructions' description with XML and design of control platform's instruction library.This paper also finishes the development of graphical program editing interface and interpretive layer running in the PLC operation system.One of them is used for showing the XML file graphically and the other is used to turn the XML file into program which can run in operation system.Finally,this paper test the full control system by applying the control platform into machine vision detecting system.The result of this experiment prove this control platform can complete program editing and other related tasks to achieve user's control requirements and achieve the desired goals of this paper.