Since the Years 60, the law of Moore predicts that the complexity in terms of built-in circuit transistors doubles every two years, remain verified. The programmable FPGA circuits (Field Programmable Gate Array) didn't escape to this law. Since the first FPGA, developed like an evolution natural of the CPLD (Complex Programmable Logic Devices), these circuits didn't stop winning in complexity a...

The concept of fuzzy reasoning has been extended to Petri nets and has been applied for modeling of discrete event systems [1]. However, the theory was not extended to supervisory control of discrete event systems because there is no valid translation for fuzzy Petri nets into ladder logic diagrams. Discrete event systems are time and event dependent and hence digital in nature. However, discre...

The dynamic behavior of an industrial tunneltype furnace is of the fundamental importance for the quality of the processed products. The knowledge of the furnace dynamics can make the control of the system easier as well as it can eliminate certain operational problems. The various subsystems existent in a tunnel-type furnace are usually controlled by conventional techniques and independent con...

The use of service-oriented architectures based on web services in the manufacturing layer of industrial enterprises enables vertical integration and promises increased interoperability. Unfortunately, the differing execution patterns—cyclic execution on programmable logic controllers vs. on-demand execution on industrial PCs—complicate the use of web services in the manufacturing layer. This p...

Current supervisory control and data acquisition (SCADA) systems do not have adequately tailored security solutions. Programmable logic controllers (PLCs) in SCADA systems are particularly vulnerable due to a lack of firmware auditing capabilities. Since a PLC is a field device that directly connects to a physical system for monitoring and control, a compromise of its firmware could have devast...

We give timed automaton models for a class of Programmable Logic Controller (PLC) applications, that are programmed in a simple fragment of the language Instruction Lists as defined in the standard IEC 1131-3. Two different approaches for modelling timers are suggested, that lead to two different timed automaton models. The purpose of this work is to provide a basis for verification and testing...

Programmable Logic Controllers are widely used in industry. Reliable PLCs are vital to many critical applications. This paper presents a novel symbolic approach for analysis of PLC systems. The main components of the approach consists of: (1) calculating the uncertainty characterization of the PLC systems, (2) abstracting the PLC system as a Hidden Markov Model, (3) solving the Hidden Markov Mo...