Research And Implementaion Of Logic And Motion Control Function Block Based On PLCopen

Due to the drawbacks of the traditional motion control system, such as a wide range of controller hardware, not unified editing language and the lack of scalability, on the basis of the study of IEC61131-3 standard programming language and PLCopen standard motion function module, motion control system is developed based on PLCopen standard to implement the combination of PLC logic instruction and PLCopen motion control instruction. On the hardware platform with IPC and PMAC motion control card as the main control unit, experimental verification of the control system is carried out.Aiming at the problem of multiple output of the the instruction compiling module, the conversion algorithm of PLC function block diagram(FBD) to instruction list(IL) based on Nary Trees is proposed and implemented. In this algorithm, firstly, the FBD program is mapped to the Nary Trees. On this basis, through decomposition and reorganization of the Nary Trees, the complex tree structure generation is decomposed into a collection of ordered subtree structure. And then the decomposed tree structures are sequentially visited in the post-order traversal way. Depending on the different nodes types which are translated into the corresponding IL.Experimental verification of soft PLC host computer system, based on the IEC61131-3 international standard, is carried out. The experimental result indicates that the algorithm is a general conversion algorithm for conversion of FBD with complex Series-parallel relationships and Layers of Multiple Outputs into IL. the algorithm can optimize generated IL instructions into the Hex target instruction,which preferably save more memory space and improve the efficiency of PLC FBD compilation conversion.Due to different execution ways between the PLC logic instruction and PLCopen motion control instruction, operation module parse and execute different instructions by using the way of stack mechanism and message queue, respectively. In order to effectively prevent the confusion caused by one axis enabled by the number of function blocks at the same time, the system allocates a control message queue for each axis and the motion function block to be executed is deposited in the message queue. Aiming at the problem of PLCopen motion function block motion parameter transfer, the method, based on structure body, is proposed and the motion parameters are deposited in the structure objects. By using this method, it not only avoids the waste of time caused by the motion parameters of the operating system, but also improves the efficiency of the motion control commands parsing execution.Finally, based on the hardware platform with IPC and PMAC motion control card, experimental verification of the control system is carried out. The results indicate that the control system meets the requirements in practical application.