Research And Implementation Of The Software Of PLC Ladder Diagram Based On SIPROM

With the rapid development of numerical control technology, the Computer Numerical Control (CNC) makes higher demands for the core of logic control, and its logic control is achieved through programmable logic controller (PLC). PLC is the critical part to enable all parts of CNC work effective and reliable, so PLC programming tool is an essential part of CNC. The PLC programming language of LanTian(LT) CNC is SIPROM, which is a textural language. The research and implementation on the transformation software between Ladder Diagram (LD) and SIPROM in this paper are just for LT CNC to realize graphical programming and real-time monitoring of the PLC. For the completion of the software, the main issues to be addressed are as follows:The design and implementation of LD editor including the design and implementation of LD primitives, editing interface, editing tools and verifying the legitimacy on the parameter input process according to SIPROM.The algorithm and realization of transformation from LD to SIPROM based on treating LD components separately by classification. In this algorithm Virtual node is be introduction, and then it is combined to establish activity on vertex (AOV) diagraph. Nodes are treated according to their types and the topological sorting of the AOV diagraph, then the transformation from LD to ST is achieved.The design and implementation of conversion algorithm from LD to SIPROM: First SIPROM is standardized, and then the coordinates of the variables of SIPROM are calculated according to its corresponding LD, so the SIPROM sentence is converted to intermediate code, which finally converted to LD.The design and implementation of PLC real-time monitoring: PLC obtain the data of LD primitives from I/O image table of CNC, and display LD primitives with different colors according this data to real-time monitor the value of each primitives.The research and implementation on the transformation software between LD and SIPROM provides visual programming, decreases the threshold of programming and Real-time monitoring of PLC of LT CNC, and helps to the promotion of domestic CNC and entering the international market.