IEC 61131-3 + ACPLT = Dynamic Reconfigurable Models

IEC 61131 [3] is a well-established international standard for programmable logic controllers (PLCs). Programming environments applying the IEC 61131 follow the “traditional” development cycle: edit-compile-load-execute. In case execution code needs to be modified, interruption of the execution is necessary. In this paper, we present an approach that combines object oriented ACPLT technologies with the standard IEC 61131-3 languages Function Block Diagram (FBD) and Sequential Function Chart (SFC). In contrast to traditional systems, the entire object-oriented meta-model of FBDs and SFCs is available on the runtime system. A great advantage of this design is the possibility of online exploration of meta-information and dynamic reconfiguration of the system without interruption. This is especially useful for maintenance and re-engineering tasks for chemical and metallurgical plants, where interruption is often associated with high economic loss. We first present a general description of the IEC 61131 and the ACPLT technologies. After this, our approach will be explained in more detail. A description of ongoing and future work concludes this paper.