Formal design methodology for transforming ladder diagram to Petri nets: Scope of the LDPN.

Abstract Control algorithms for programmable logic controllers are still developed based on the experience of those responsible for control in the industry. The IEC-61131-3 standard considers five programming languages: Ladder Diagram, Structured Text, Function Block Diagram, Instruction List, and Sequential Function Diagram, which use different function blocks to develop control algorithms. Within the control algorithms for discrete event systems there are two types of blocks: those with discrete inputs and outputs, and those with discrete and analog inputs and discrete output. Of the latter, the present research shows the analysis and formal model of the blocks including the problems of accumulation of tokens and the restoration of the coils. Expanding the scope of the Ladder Discrete Petri Net proposal and therefore the analysis and simulation of control algorithms with a greater degree of complexity.