文档介绍：Visualization of PLC Programs using XML
M. Bani Younis and G. Frey
Juniorprofessorship Agentenbased Automation
University of Kaiserslautem
P. 0. Box 3049, D-67653 Kaiserslautem, Germany
Abstract - Due to the plexity of PLC programs there is an increasing interest in the application of formal methods in this area. Formal methods allow rigid proving of system properties in verification and validation. One way to apply formal methods is to utilize a formal design approach in PLC programming. However, for existing software that has to be optimized, changed, or ported to new systems .There is the need for an approach that can start from a given PLC program. Therefore, formalization of PLC programs is a topic of current research. The paper outlines a re-engineering approach based on the formalization of PLC programs. The transformation into a vendor independent format and the visualization of the structure of PLC programs is identified as an important intermediate step in this process. It is shown how XML and corresponding technologies can be used for the formalization and visualization of an existing PLC program.
I. INTRODUCTION
Programmable Logic Controllers (PLCs) are a special type puters that are used in industrial and safety critical applications. The purpose of a PLC is to control a particular process, or a collection of processes, by producing electrical control signals in response to electrical process- related inputs signals. The systems controlled by PLCs vary tremendously, with applications in manufacturing, chemical process control, machining, transportation, power distribution, and many other fields. Automation applications can range plexity from a simple panel to operate the lights and motorized window shades in a conference room pletely automated manufacturing lines.
With the widening of their application horizon, PLC programs are being subject to plexity and high quality demands especially for safety-critical applications. The plexity of the app