IEC 61131-3 Integrated Development Environment

for this standard, however small inconsistencies remain between their implementations, transferring programs between vendors is almost impossible due to different file formats, and licenses are generally too expensive to allow students do install these commercial solutions on their own computers. To this end, the authors have developed an Integrated Development Environment (IDE) for the IEC 61131-3 framework, which is being offered to the general public under the GNU Public License (GPL). The IDE consists of a Graphical User Interface (GUI) and a backend compiler. Using the GUI the user may develop programs in any of the four programming languages, as well as the state machine definition language. The backend compiler is used to convert these programs into equivalent C++ programs which may later be compiled and executed on various platforms. I.INTRODUCTION HE proliferation of PLCs (Programmable Logical Controllers) used in an industrial setting is indicative of their usefulness. These have evolved with the times, to the point that many modern top of the range PLCs are actually full fledged computers in disguise, executing modern operating systems. The hardware inside many vendor's PLCs has a tendency to become similar to PCs (Personal Computers) in order to take advantage of economies of scale. On the other hand, the diversity of the programming languages used between different vendors, along with their increased complexity, has led to larger learning times for the programmer when switching between PLC. To this end, the IEC (International Electrotechnical Commission), an international standards body, has approved a collection of standards with the intention of creating a common user experience when configuring and programming industrial controllers. One of the components of this standard, namely the IEC 61131-3 [1], defines how the user may program the PLCs, and includes a programming framework and several programming languages. Nevertheless, even though both the hardware and the software aspect of differing vendor PLCs are becoming similar, the vendors are still able to lock users into their line of products using several techniques which we shall M anuscript not discuss. Additionally, and just like any other programming language, learning and becoming proficient with these programming languages requires that the student practice extensively program development and therefore learn from his/her mistakes and errors. Expensive licensing deals from existing vendors makes it cost prohibitive to allow students to install an IEC 61131-3 programming environment on their own personal computers. Practice is therefore limited to the few workstations …