We address the verification of programmable logic controllers (PLC). In our approach, a PLC program is translated into a special type of colored Petri net, a so-called register net (RN). We present analysis methods based on the partial order semantics of RN’s, which allow the generation of partial order traces as counter examples in the presence of programming errors. To that purpose, the behav...

In this paper, an architecture of the RISC processor for pro-grammable logic controllers is proposed. Execution characteristics of relay ladder logic, the most common language of PLCs, are analyzed with various application programs. A conditional execution mechanism is developed to prevent pipeline hazards caused by the inherent execution behaviour of relay ladder logic. The instruction sets of...

This paper deals with realization and implementation of a new type fractional order controllers (FOC) based on programmable logic controllers series BR 2005 and their utilization to temperature control with big time constant. As the object was used electrical heater, where controlled value is the temperature of hot air, which is fluctuant from heater.

Mechatronic engineering is about integration of different engineering disciplines, mainly mechanical engineering, electrical engineering, and software engineering. Within the machine and plant engineering process, software engineering is part of automation engineering, which deals with configuration and programming of devices like programmable logic controllers (PLC), motion controllers, and hu...

Throughout the ages people have been working in research institutes and industries in machine automation so as to have less involvement of operator in machine operations. In the development of automation controllers the trend has been to move towards soft controllers so as to provide better control, more flexibility and more reliability with intelligent diagnostics of machine faults. So industr...

The international standard MMS (Manufacturing Message Specification) is an OSI application layer messaging protocol origionally designed for the remote control and monitoring of devices such as Remote Terminal Units (RTU), Programmable Logic Controllers (PLC), Numerical Controllers (NC), or Robot Controllers (RC). It provides a set of services allowing the remote manipulation of variables, prog...

Fuzzy Logic controllers have been successfully applied in a large number of control applications, with the most commonly used controller being the PID controller. Fuzzy logic controllers provide an alternative to PID controllers, as they are a good tool for the control of systems that are difficult to model. The control action in fuzzy logic controllers can be expressed with simple “if-then” ru...

The proposed reactive real{time programming system is a new approach to implement complex distributed heterogeneous real-time applications. It is based on the notion of distributed multi{agent systems. The whole control task is decomposed top down into small execution units, called agents which communicate by sending and executing contracts and are speciied in a hardware independent language ba...