With the increasing use of computers in manufacturing, the quality of the production process becomes increasingly dependent on the software used in these systems. This paper describes the use of Lamport’s Temporal Logic of Actions (TLA) for the modular verification of programmable logic controllers (PLCs). First, a way to formulate abstract specifications for function blocks as defined in IEC 1...

This paper presents a case-study for the optimization, the monitoring and the automatic control of a refrigeration system in a commercial store. The existing controllers were replaced by Omron temperature controllers, connected to an industrial network and linked to a central computer for data monitoring and temperature control using a LabView software. In case of an alarm occurrence, this syst...

This paper presents a fault tolerant configuration for a multiple discrete control system. The distributed control nodes, such as programmable logic controllers, communicate over networks. The design methodology of an additional redundant controller using Galois field and an error-detecting code is proposed. The proposed method is implemented and tested on distributed controllers connected on a...

The paper is focusing on Human Machine-Interface implementation in designing crane control based on fuzzy logic algorithm. The Human Machine-Interface application was created for visualization, monitoring and managing the transportation process realized by the crane. Control systems based on fuzzy controllers with Mamdani and Sugeno inference systems were elaborated and built using prototyping ...

Industrial process control is an untapped market for field programmable gate arrays (FPGAs). Programs used for industrial process control are traditionally written in a graphical language called relay ladder logic, and implemented on programmable logic controllers (PLCs). The mapping of ladder logic onto typical FPGAs is a lengthy process, and results are hard to verib. We propose an FPGA archi...

Scheduling Algorithm for Programmable Logic Controllers with Remote I/O's p. 87 Concurrency Control for Real-Time Database Systems with Mixed Transactions p. 96 Scheduling Real-Time Read-Only Transactions p. 104 An Index Recovery Method for Real-Time DBMS in Client-Server Architecture p. 110 An Implementation and Performance Analysis of Backup System Using Concurrent Log Processing in Real-Time...

Ladder logic is a graphical language widely used to program Programmable Logic Controllers (PLCs). PLCs are found at the heart of most industrial control systems used in automation because they are robust, they are relatively easy to program and because they are a proven technology. However there is currently no means to measure the intrinsic properties and qualities of the code produced. This ...

We present an algorithm for synthesizing real-time controllers specified in a subset of the interval temporal logic duration calculus. The synthesized controllers are given in terms of programmable logic controller (PLC)-automata, which are an abstract description of programs of polling machines. PLCautomata can be implemented directly on PLC’s, a special kind of polling real-time controllers t...