Idea of Description on Ladder Diagram's Data Structure for PLC
Kang Ji-chang · Computer Engineering and Science · 2009
Aiming at the complexity and limitation of the storage structure of the edit software for the PLC ladder diagram (LD),based on the object-oriented method,the paper adopts the data structure which combines binary trees and double linked lists to describe the functional units and their topological connections in LD,and proposes a transformation algorithm.Then the paper simplifies the structure and transforms it to a model that contains the functional units only,which avoids the difficulty from the transformation of LD to instruction list(IL).The structure is simple,and has strong interoperability.It is very easy to implement the structure with the C++ language,which is applied well in the edit software for PLC LD.