In the field of the industrial automatic control, both MCU (Micro Control Unit) and PLC (Programmable Logic Controller) are widely being used in DCS (Distributed Control System). Since MCU can provide complex process scheduling, accurate timing control and PLC has the advantages of easy programming and maintaining. However, the control programs of the MCU are hard to design and maintain. Identically, the poor signal processing ability, high cost and the restrictive functions are the major defects of PLC. In order to solve the drawbacks described above in MCU and PLC, we provide a PLC-like interface for users to access the devices and set the registers of MCU. Likewise, designers can develop the control program via Event-table-driven modules. On the other hand, our main goal of DCS is to quickly construct the distributed N level network topology based on Modbus protocol, which is efficient and reliable. Therefore, we bring up a data collection method and Slave-to-Slave strategy so as to distribute the master loading, reduce the package transmission times and improve the real-time latency. In conclusion, our research results not only congregate the benefits of MCU and PLC but provide an environment to quickly construct and conveniently monitor DCS, which meets the time-to-market demands.

This thesis deals with the identification of automated discrete event systems (DES) operating in an industrial context. In particular the work focuses on the systems composed by a plant and a programmable logic controller (PLC) operating in a closed loop- the identification consists in obtaining an approximate model expressed in interpreted Petri nets (IPN) from the observed behaviour given under the form of a single sequence of input-output vectors of the PLC. First, an overview of previous works on identification of DES is presented as well as a comparative study of the main recent approaches on the matter. Then the addressed problem is stated- important technological characteristics of automated systems and PLC are detailed. Such characteristics must be considered in solving the identification problem, but they cannot be handled by previous identification techniques. The main contribution in this thesis is the creation of two complementary identification methods. The first method allows constructing systematically an IPN model from a single input-output sequence representing the observable behaviour of the DES. The obtained IPN models describe in detail the evolution of inputs and outputs during the system operation. The second method has been conceived for addressing large and complex industrial DES- it is based on a statistical approach yielding compact and expressive IPN models. It consists of two stages- the first one obtains, from the input-output sequence, the reactive part of the model composed by observable places and transitions. The second stage builds the non observable part of the model including places that ensure the reproduction of the observed input-output sequence. The proposed methods, based on polynomial-time algorithms, have been implemented in software tools, which have been tested with input-output sequences obtained from real systems in operation. The tools are described and their application is illustrated through two case studies.

Η παρούσα διπλωματική εργασία περιλαμβάνει την πλήρη αυτοματοποίηση του τρόπου παραγωγής και διανομής των ηλεκτρικών παροχών στο Εργαστήριο Ηλεκτρομηχανικής Μετατροπής Ενέργειας του Τμήματος Ηλεκτρολόγων Μηχανικών και Τεχνολογίας Υπολογιστών. Το πρώτο μέρος της παρούσας διπλωματικής εργασίας αφορά την περιγραφή του συστήματος παροχών του ΕΗΜΕ. Γίνεται περιγραφή του υπάρχοντος εξόπλισμου και εξετάξεται η δυνατότητά του να λειτουργήσει με PLC. Στην συνέχεια γίνεται περιγραφή της διαδικασίας προγραμματισμού του PLC και ο τρόπος που δομείται το εποπτικό περιβάλλον SCADA. Τέλος γίνεται ιδιαίτερη αναφορά σε κάποιες δυνατότητες που παρέχει το νέο πλήρως αυτοματοποιημένο σύστημα, όπως η δυνατότητα αυτόματου παραλληλισμού σύγχρονης μηχανής με το δίκτυο της ΔΕΗ και η διόρθωση τού συντελεστή ισχύος της εγκατάστασης. / The present diplomatic work includes the complete automation of way of production and distribution of Power supply in the Laboratory of electromechanis Transformation of Energy at the Department of Electricians of Engineers and Technology of Computers.

Η διπλωματική αυτή εργασία, συνίσταται στην μελέτη των αυτοματισμών παραγωγής της διαδικασίας επεξεργασίας γάλακτος στη βιομηχανία Ροδόπη Α.Ε. καθώς και στη συλλογή δεδομένων και τον εποπτικό έλεγχο αυτής. Επιπρόσθετα, αναπτύχθηκε εξαρχής η αυτοματοποίηση και η ανάπτυξη συστήματος SCADA του βιολογικού καθαρισμού της πιο πάνω βιομηχανίας. Για την εκπόνηση της διπλωματικής εργασίας, ήταν αναγκαία η τετράμηνη πρακτική εργασία μου στη βιομηχανία Ροδόπη Α.Ε. από τις 1-7-2011 έως τις 31-10-2011, γεγονός που μου επέτρεψε να συλλέξω τα απαιτούμενα στοιχεία για την αναλυτική περιγραφή των διαφόρων σταδίων της παραγωγικής διαδικασίας. Η αυτοματοποίηση πραγματοποιήθηκε με τη χρήση ενός PLC και ενός συστήματος SCADA. Στην πρώτη φάση υλοποίησης της διπλωματικής εργασίας, προγραμματίστηκε ένα PLC το οποίο θα αναλάμβανε τον κυρίως έλεγχο της εγκατάστασης μετρώντας όλα τα χρήσιμα για τον έλεγχο μεγέθη (στάθμη δεξαμενών, ρεύμα κινητήρων, pH κλπ) και αντιδρώντας αντίστοιχα σε κάθε μεταβολή των μεγεθών αυτών. Η δεύτερη φάση, περιελάμβανε την ανάπτυξη ενός συστήματος SCADA για την εποπτεία και την παρακολούθηση της εγκατάστασης. Για να μπορέσει αυτό το σύστημα να αναλάβει το έλεγχο της εγκατάστασης, το PLC και το SCADA επικοινωνούν μέσω ενός δικτύου MPI, μέσω του οποίου πραγματοποιείται η συνεχής ενημέρωση της εκάστοτε συσκευής για τις αλλαγές που πραγματοποιούνται στην άλλη. Έτσι, σχεδιάστηκε ένα σύστημα SCADA, το οποίο δίνει τη δυνατότητα στο χειριστή να επεμβαίνει στο σύστημα και να μπορεί ανά πάσα στιγμή να γνωρίζει οποιαδήποτε πληροφορία χρειάζεται για την εγκατάσταση με τον ευκολότερο δυνατό τρόπο. / -

The content of the thesis is to familiarize students with module PLC Siemens LOGO! and its practical use in teaching courses in the subjects as automation, electro-nics and mechatronics at vocational secondary schools. The content is focused on the basic description of the development and graphical environment and its use in practical problems solving. In the practical part of the proposals there are worksheets for pupils with the design of pupils´ simple tasks. After studying this text and the compilation of practical problems, the student should be capable of independent operation with module PLC Siemens LOGO! and implementation of complex applications.

Most SCADA devices have a few built-in self-defence mechanisms and tend to implicitly trust communications received over the network. Therefore, monitoring and forensic analysis of network traffic is a critical prerequisite for building an effective defense around SCADA units. In this thesis work, We provide a comprehensive forensic analysis of network traffic generated by the PCCC(Programmable Controller Communication Commands) protocol and present a prototype tool capable of extracting both updates to programmable logic and crucial configuration information. The results of our analysis shows that more than 30 files are transferred to/from the PLC when downloading/uplloading a ladder logic program using RSLogix programming software including configuration and data files. Interestingly, when RSLogix compiles a ladder-logic program, it does not create any lo-level representation of a ladder-logic file. However the low-level ladder logic is present and can be extracted from the network traffic log using our prototype tool. the tool extracts SMTP configuration from the network log and parses it to obtain email addresses, username and password. The network log contains password in plain text.

The diploma thesis is a part of the project Intelligent weighting and sorting of goods. The principle of measuring of weight from movement dynamics with derivation calculation relation is detailed described in the first part. The description of used automation means is also in the first part of the diploma thesis. The second part includes design of three adaptive control systems for controlling DC electromotor’s arm, communication principles between programmable logic controllers and designed code of program.

This thesis describes the design and implementation of device called Intelligent two-arm juggling machine. The role of the demonstration project is to control rotational movement of the arm so that the concept of the machine there to swap the ball to the opposite side shoulder. The project is divided into two theses, which this proposal addresses the above mentioned tasks, the machine and place the second level ofcooperative governance through visualization.

Projektet går ut på att ersätta den befintliga styrningen av en DC-generator för 1200 kV med en fjärrstyrning från kontrollrummet via optolänk. Den nya styrningen ska utgöras av ett PLC-system (Programmable Logic Controller) som manövreras med hjälp av ett HMI – Human Machine Interface. Bakgrunden till projektet härrör från att den befintliga styrutrustningen är opålitlig samt styrs i en farlig miljö. Rapporten går igenom hur befintlig styrutrustning fungerar samt dess ingående komponenter, hur ett PLC-system fungerar med dess bakgrund och olika programmeringsspråk. Även programmeringen och byggnationen av det nya systemet avhandlas. I slutet av rapporten ges en genomgång av de provkörningar som utförts för att säkerställa att alla funktioner fungerar som tänkt. Resultat av provkörningarna ges och diskussion förs kring projektet. Projektet är utfört åt högspänningsgruppen på RISE i Borås som använder generatorn bland annat vid kalibrering av spänningsdelare. Det nya styrsystemet innefattar alla av den tidigare styrutrustningens funktioner och några nya funktioner så som överströms- och överspänningsskydd vilka slår från spänningsmatningen om dessa begränsningar överskrids. Att styrutrustningen nu är placerad i kontrollrumsmiljö gör att operatören kan hantera utrustningen utan att vara i närheten av farlig spänning. / The report aims to replace the current control equipment for a DC-generator for 1200 kV by remote control from control room through optical fibre link. The new control will be a PLC system controlled by a HMI – Human Machine Interface. The background to the project is that the existing control equipment is unreliable and controlled in a dangerous environment. The report shows how the current control equipment works and its constituent components, how a PLC-system works with its background and different programming languages. This report will also describe how the programming and building of the hardware are done. In the end of this report are going through a test run to confirm that the system is working properly. Result of the test run are given and some discussion. The project is initiated by the high voltage group at RISE in Borås, who are using the DC-generator for instance while calibrating voltage dividers. The new control system contains all of the functions from the earlier control system but also some new functions such as overcurrent and overvoltage protection who turns off power supply if the limits are exceeded. The control system is now located in the control room so that the operator can use the system without being close to high voltage.

Concurrent software has been widely utilizing in computer systems owing to the highly efficient computation. However, testing and verifying concurrent software remain challenging tasks. This matter is not only because of the non-deterministic thread interferences which are hard to reason about but also because of the large state space due to the simultaneous path and interleaving explosions. That is, the number of program paths in each thread may be exponential in the number of branch conditions, and also, the number of thread interleavings may be exponential in the number of concurrent operations. This dissertation presents a set of new methods, built upon symbolic execution, a program analysis technique that systematically explores program state space, for testing concurrent programs. By modeling both functional and non-functional properties of the programs as assertions, these new methods efficiently analyze the viable behaviors of the given concurrent programs. The first method is assertion guided symbolic execution, a state space reduction technique that identifies and eliminates redundant executions w.r.t the explored interleavings. The second method is incremental symbolic execution, which generates test inputs only for the influenced program behaviors by the small code changes between two program versions. The third method is SYMPLC, a technique with domain-specific reduction strategies for generating tests for the multitasking Programmable Logic Controller (PLC) programs written in languages specified by the IEC 61131-3 standard. The last method is adversarial symbolic execution, a technique for detecting concurrency related side-channel information leaks by analyzing the cache timing behaviors of a concurrent program in symbolic execution. This dissertation evaluates the proposed methods on a diverse set of both synthesized programs and real-world applications. The experimental results show that these techniques can significantly outperform state-of-the-art symbolic execution tools for concurrent software. / Doctor of Philosophy / Software testing is a technique that runs software as a black-box on computer hardware multiple times, with different inputs per run, to test if the software behavior conforms to the designed functionality by developers. Nowadays, programmers have been increasingly developing multithreaded and multitasking software, e.g., web browser and web server, to utilize the highly efficient multiprocessor hardware. This approach significantly improves the software performance since a large computing job can now decompose to a set of small jobs which can then distribute to concurrently running threads (tasks). However, testing multithreaded (multitask) software is extremely challenging. The most critical problem is the inherent non-determinism. Typically, executing sequential software with the same input data always results in the same output. However, running a multithreaded (multitask) software multiple times, even under the same input data, may yield different output in each run. The root reason is that concurrent threads (tasks) may interleave their running progress at any time; thus the internal software execution order may be altered unexpectedly, causing runtime errors. Meanwhile, finding such faults is difficult, since the number of all possible interleavings can be exponentially growing in the number of concurrent thread (task) operations. This dissertation proposes four methods to test multithreaded/multitask software efficiently. The first method summarizes the already-tested program behaviors to avoid future testing runs that cannot lead to new faults. The second method only tests program behaviors that are impacted by program changes. The third method tests multitask Programmable Logic Controller (PLC) programs by excluding infeasible testing runs w.r.t the PLC semantics. The last method tests non-functional program properties by systematic concurrency analysis. This dissertation evaluates these methods upon a diverse set of benchmarks. The experimental results show that the proposed methods significantly outperform state-of-the-art techniques for concurrent software analysis.