Program slicing has been used as a way to improve the efficiency of debugging and program analysis. Nowadays, automated test generation is being used to create tests automatically by analysing the program structure and suggesting necessary tests. This kind of techniques are prone to efficiency problems when applied to large programs containing many lines of code. This is especially true for software in industrial practice, such as the ones running on Programmable logic controllers (PLC) that are used in a wide variety of tasks from toys to avionics and rail transport. Function Block Diagram (FBD) is a language used for programming PLCs that has gained lots of attention in industrial practice due to its graphical nature. These FBD programs are often used in real time and safety critical systems, and these systems require extensive testing in order to prove that they pass safety requirements of their respective domains. In order to improve the efficiency of applying automated test generation on FBD programs we propose two FBD program slicing algorithms based on the structure of these diagrams and how they are programmed. These FBD program slicing algorithms are applied on several industrial programs for PLCs in order to evaluate their feasibility and what effect slicing has on test generation. Six FBD programs were selected out of 189 provided by Bombardier Transportation Sweden AB. The six programs were sliced according to these FBD slicing algorithms and then evaluated in terms of efficiency and applicability. Our results suggest that slicing can be used to reduce the needed generation time and memory usage required for automated test generation. However, our observations show that slicing can also increase the number of test cases generated and how this test cases are merged into one test suite for the entire program.

Masters thesis deals with the SIMATIC, which is the process control system from Siemens. Simatic belongs to the group of so-called programmable logic controllers (English Programmable Logic Controller). It is a microcomputer that processes the instructions in real time. I have designed a control algorithm and HMI visualization in my Masterś thesis. Moreover,my attention is focused on PLC S7 - 300. The S7-313C is used for implementations. The proposed solution has been tested and operated in real conditions

Med hjälp av systembilder, PLC-kod, studiebesök och intervjuer konstruerades en funktionsbeskrivning för styrning och hantering av ett värmeåtervinningssystem vid namn Avgaspannan, på Volvo GTOs, f.d. Powertrain, anläggning i Skövde. Syftet bakom examensarbetet var att skapa en funktions-beskrivning som skulle vara ett stöd för nuvarande, men även blivande personal. Eftersom det i dags-läget inte finns någon dokumentation kring styrningen av systemet. Tanken bakom arbetet är att med hjälp av redan existerande programkod och systembilder skapa en väldokumenterad och välfylld funktionsbeskrivning. För att komplettera dokumentet till största möjliga mån, genomfördes även studiebesök för att se systemet i verkligheten samt genomfördes även intervjuer för att erhålla information och kommentarer från driftpersonalen. Värmeåtervinningssystemet utvinner värmen från producerade avgaser från smältugnarna i Gjuteriet. Värmen som utvinns värmer i sin tur upp fjärrvärmevatten som sedan pumpas ut på Skövde kommuns Fjärrvärmenät för att under vinterhalvåret hjälpa till och förse Skövde med värme. De steg och moment som utfördes under arbetets gång har resulterat i ett godkänt dokument hos aktörerna och de är nöjda med arbetet. För att kunna nå det färdiga resultatet genomfördes studier kring och i PLC-programmet samt systembilder, det utfördes även studiebesök och intervjuer. Dessa mo-ment var byggstenarna för att kunna få ett godkänt resultat. / With the aid of system images, PLC-code, studies at the facility and interviews, a functional description was designed for the control and management of a waste heat boiler named Avgaspannan, at Volvo GTOs, Powertrain, plant in Skövde. The purpose of the thesis was to create a functional description that would support current, but also prospective staff. Since there is currently, no documentation regarding the control of the system. The idea behind the work is to create a well-documented and well-filled function description by using already existing program-code and system images. To supplement the document to the greatest extent possible, studies at the facility and the real system was made. Interviews were also conducted to obtain information and comments from the operating staff.The heat recovery system extracts the heat from produced exhaust gases from the smelters in the foundry. The heat that is extracted, will heat up the district heating water, which is then pumped out on Skövde municipality’s heating network in order to help and provide Skövde with heat during the winter. The steps performed during the course of the work have resulted in an approved document by the actors and they are satisfied with the work. To be able to achieve the final result, studies were conducted on and in the PLC-code and system images, as well as study visits and interviews. These elements were the building blocks for being able to get an approved result.

Testing safety-critical systems, particularly those controlled by Programmable Logic Controllers (PLC), is crucial for ensuring the safe and reliable operation of industrial processes. This thesis addresses the critical need for automated testing of safety-critical PLC systems used in various industrial settings. Despite the significance of testing, current practices rely heavily on manual methods, leading to challenges in scalability and reliability. This work investigates enabling test automation for PLCs to facilitate and assist the current manual testing procedures in the industry. The thesis proposes and evaluates test automation techniques and tools tailored to PLCs, focusing on Function Block Diagram and Structured Text languages commonly used in industry. We systematically compare test automation tools for PLC programs, after which we propose a PLC to Python translation framework called PyLC to facilitate automated test generation. The experiment employing the EARS requirement engineering pattern reveals that while engineers use semi-formal notations in varied ways to create requirements, leading to completeness issues, it confirms the viability of employing EARS requirements for PLC system testing. Subsequently, the proposed automation approaches are fully implemented and evaluated using real-world PLC case studies, comparing their efficiency against manual testing procedures. The findings highlight the feasibility and benefits of automating PLC testing, offering insights into improving development and testing processes through carefully selected automation tools for the CODESYS IDE, a well-known PLC development environment. Additionally, we show that leveraging Python-based automated testing techniques and mutation analysis enhances testing effectiveness. Furthermore, incorporating best practices in requirement engineering, as demonstrated by the EARS approach, contributes to further enhancing testing efficiency and effectiveness in PLC development. / VeriDevOps, SmartDelta

This thesis deals with the design of automated system of electroplating. The first part is centered on designing the technological process for this electroplating and the setout of operating vats. It also deals with the project of mechanical construction, electrical system, with the computing procedure and the optimum choice of gear for galvanic line model. The work includes the design of a DC motor controller, the computing procedure and the construction of heating element for vats heater simulation. The last part of this thesis offers an insight to the control system and the assembled program. In the addendum, the photo of the realized model, the wiring scheme, and the programme transcript for control galvanic line model can be found.