IEEE TRANSACTIONS ON INDUSTRIAL INFORMATICS, VOL. XX, NO. X, MONTH YYYY 1 A Novel Approach for Integrating IEC 61131-3 Engineering and Execution into IEC 61499 Peter Gsellmann 1 , Martin Melik-Merkumians 1 , Member, IEEE, IES, Alois Zoitl 2 , Member, IEEE, IES, and Georg Schitter 1 , Senior Member, IEEE Abstract—Automation system engineering becomes more com- plex, due to the trend towards more flexible, reconfigurable, and modular design approaches, like Industry 4.0. For the modeling and design of the according software, two standards are present: IEC 61131-3 and IEC 61499. In order to satisfy the requirements for modern, large scale, highly-distributed applications while also supporting still existing legacy systems, the demand for a combined development framework arises, where the best of breed tool can be chosen for a given automation task. Considering that, the IEC 61499 model is extended to allow the dual development and execution of IEC 61131-3 programs, and enabling easy and correct interaction between the two paradigms. In order to verify the validity of the chosen approach, an IEC 61499 development tool and a runtime environment is modified to support IEC 61131-3. A sample application is implemented, which comprises a pure IEC 61131-3 part with a 1 ms cycle time, a pure IEC 61499 part, and a part with interaction between both subparts, in order to evaluate possible interference between the runtime parts. Experimental results show that no interference is occurring, and the chosen development approach allows the seamless integration of IEC 61131-3 and IEC 61499 in one combined development framework. Index Terms—IEC 61499, IEC 61131, interoperability I. I NTRODUCTION I N CURRENT automation systems, control software is the main driver for functionality and innovation, and therefore is a significant component. Hence, its development makes a large share of the overall costs. Considering nowadays trend towards Industry 4.0, the requirements regarding interoper- ability, flexibility, and reconfigurability gain importance [1]. Currently, when developing such systems, engineers have to choose between two prominent standards: the IEC 61131- 3 – Programmable controllers: Programming languages [2] and the IEC 61499 – Function blocks [3]. The IEC 61131- 3 standard’s main focus was on easy-to-use programming languages, and single Programmable Logic Controller (PLC) systems, each controlling a defined section of the production process. With the move to modern large scale applications, the control software development had to deal with features like adaptability, reusability, and distributability. IEC 61131- 3 evolved (e.g., object-oriented extensions, IEC 61131-5 for communication) to meet these new needs, though it was never Manuscript received July 7, 2020; revised September 18, 2020; accepted October 19, 2020. 1 P. Gsellmann, M. Melik-Merkumians, and G. Schitter are with the Au- tomation and Control Institute, TU Wien, Vienna, 1040 Austria. 2 A. Zoitl is with the LIT Cyber Physical Systems Lab, JKU, Linz, 4040 Austria. Corresponding author: gsellmann@acin.tuwien.ac.at designed with these developments in mind [4]. Consequently, a new architecture, the IEC 61499, was developed to satisfy these emerging requirements. Nevertheless, IEC 61131-3 based systems are still prevalent in industry, due to legacy systems and well-trained staff for this type of programming model. There have been initiatives to support the transition by enabling re-use of the already existing PLC applications. Several studies analyzed and realized tools for a semantic transformation from IEC 61131-3 to IEC 61499 [5], [6], [7]. However, in the recent years, due to the trend towards highly-distributed Cyber-Physical Production System (CPPS), the distribution aspect of control systems became more relevant. This is where IEC 61499 excels, as this distri- bution aspect was considered in the design process. Although, IEC 61131-3 could be extended to support model driven design and planning of distributed control, this is a nontrivial task [8]. In this aspect, IEC 61499 is superior to the IEC 61131-3 model, as distribution is an inherent part of IEC 61499 system design. Another important aspect of system engineering is the needed programming effort and resulting code complexity, as this directly affects engineering, commissioning, and mainte- nance effort. A recently conducted study [9] gives an objective comparison between IEC 61499 and IEC 61131-3 applica- tions based on code measures. Typical application classes in industrial automation, a sequential control and a PI control application, have been developed in both programming models and then evaluated for the suitability of each programming model for the given task. The results show, that the imple- mentation effort for the sequential task is significantly less for IEC 61499 APPLICATIONs, whereas the IEC 61131-3 Structured Text (ST)/Function Block Diagram (FBD) imple- mentation excels for control algorithms. Each programming model has its strengths and weaknesses, which translates directly into programming effort and code complexity. These new requirements demand for a combined framework for IEC 61499 and IEC 61131-3 compliant systems, in order to offer the best of breed tool for a given automation task, and thus motivate the contribution of this article. Alongside to the development of a concept for a combined IEC 61499-based Runtime Environment (RTE) and an engineering approach to model IEC 61499 and IEC 61131-3 applications, also the means to achieve easy interaction are taken into account. Furthermore, a sample application is presented, showing the validity of the presented approach. Finally, measurements are conducted to prove that the two execution units within the same device are not disturbing each other, even while Post-print version (generated on 21.10.2020) This and other publications are available at: http://www.acin.tuwien.ac.at/publikationen/ams/ Post-print version of the article: P. Gsellmann, M. Melik-Merkumians, A. Zoitl, and G. Schitter, “A Novel Approach for Integrating IEC 61131-3 Engineering and Execution into IEC 61499,”IEEE Transactions on Industrial Informatics , 2020. DOI: 10.1109/TII.2020.3033330 c 2020 IEEE. Personal use of this material is permitted. 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