Eduardo A. Mossin

A fieldbus simulator for training purposes.

This article presents a fieldbus simulation platform and its remote access interface that enables a wide range of experiments, where users can configure operation sequences and procedures typical of Foundation Fieldbus systems. The simulation system was developed using LabVIEW, with requisites of deterministic execution, and a course management work frame web server called Moodle. The results were obtained through three different evaluations: schedule table execution, simulator functionality and finally, simulator productivity and achievement. The evaluation attests that this new tool is feasible, and can be applied for fieldbus automation systems training purposes, considering the robustness and stability in tests and the positive feedback from users.

Networked control systems distance learning: state of art, tendencies and a new fieldbus remote laboratory proposal

Due to the increasing presence of the Internet in the academic and residential environment, the literature shows an increasing number of experiments of distance learning in the automation and industrial control area in the last decade, in which theoretical procedures as well as practical lessons, can be carried through remote access. In this context, this article presents a brief survey on the academic experiments in the application of on-line laboratories and introduces a new proposal of remote access architecture based on FOUNDATION fieldbus protocol using a simulated environment.

Configuration Management for Fieldbus Automation Systems

The industrial communication fieldbus protocols have evolved significantly in the last years. The advanced characteristics of instruments diagnosis and the advanced and flexible algorithms for control elaboration are some examples of advancements that have collaborated for this evolution. Considering this evolution, the automation systems have demanded more and more skilled people and tools directed to the configuration process automatization with features that must abstract the system complexity. In this context, it is presented in this paper a fieldbus configuration management approach for automation systems based on software project configuration management concepts and practices.

Artificial neural networks and signal clipping for Profibus DP diagnostics

This research proposes the use of Artificial Neural Networks to diagnose industrial networks communication via Profibus DP Protocol. These diagnostics are based on information provided by the Physical Layer from the Profibus DP Protocol. In order to analyze the physical layer, an Artificial Neural Network first analyzes signal samples transmitted through the industrial network. In case these signals show some deformation, the Artificial Neural Network indicates a possible cause for the problem, after all, problems from Profibus networks generate specific and distinctive standards imprinted on the digital signal wave formats. Before the Artificial Neural Network analysis, the signal was pre-processed through a clipper methodology. The project was validated by data obtained from concrete Profibus networks created in laboratory. The results were satisfactory, proving the great strength and versatility that intelligent computer systems have when applied to the purposes outlined in this work.

Physical diagnostic for profibus DP networks based on Artificial Neural Network

PROFIBUS (Process Field Bus) DP is the most used field communication bus in the worldwide industry. The increasing use of this fieldbus network protocol in industrial plants has made quick diagnostics for fails extremely necessary and important in order to minimize halt time during installation and the consequent financial losses in the production process. This work describe a tool based on Artificial Neural Networks (ANN), which will be used to promptly diagnose the physical layer of a PROFIBUS network in case of a failure, providing a criterial performance analysis through the basic concepts presented. In this context, this paper will briefly describe the physical layer of the mentioned protocol and the related problems, as well as the results from the performed ANN training.

Intelligent diagnostic for PROFIBUS DP networks

Digital networks for industrial automation applications, or fieldbuses, are highly sensitive to fails related to physical installations. Among all fieldbuses, PROFIBUS is one of the most used network protocol in the industrial automation area, and it is the target protocol for this work. Failing to observe technical requirements, by using excessive long cabling or lacking active bus terminals, for instance, may affect the communication performance and alter electrical characteristic of the transmission system, therefore degrading the quality of the signal being transmitted. This kind of problems can be diagnosed by analyzing the voltage levels of the signals from the network devices, considering their characteristic format, or even analyzing the behavior of the devices on the network, for example, when a device does not respond to requests or when a device sporadically connects and disconnects from the network. This work proposes the use of intelligent systems, such as Artificial Neural Networks (ANN) and Expert Systems, to perform these analyses. Besides displaying diagnostics, the system also allows the user to visually analyze the signals from the networks physical layer using an oscilloscope, and display the devices that are communicating on the network (Live List), among other features. Support provided by this system may minimize eventual false downtime for the plant and, consequently, decrease possible losses from the processes.

Integration of an open and non-proprietary device description technology in a foundation fieldbus simulator

This work describes an application and a case study of the Open-EDD technology to the supervision of a FOUNDATION Fieldbus simulation tool, based on the FBSIMU tool. The Open-EDD technology was developed base on software standards already spread for personal computers (XLST, Xerces - DOM implementation, OO, XML Schema) and it is applied in this paper as viable alternative to the currently standardized Device Description technology (IEC 61804-2 - EDD) used for the HART, PROFIBUS and FOUNDATION Fieldbus protocols. In the case of FOUNDATION Fieldbus protocol, for the integration of IEC 61804-2 EDD with FBSIMU, it is necessary to purchase an integration toolkit, that has a high cost. The fieldbus simulation is based on the FBSIMU tool that focuses on the application process of Foundation Fieldbus systems and provides all functionalities to the user considering the configuration and operation of a fieldbus strategy. The results comprehend a functional and temporal evaluation that proves the possibility to reach fieldbus interoperability with the use of truly open software standards.

Fieldbus simulator: Architecture, typical experiment and tool evaluation

This article presents a fieldbus simulation platform and its remote access interface that enables a wide range of experiments where users can configure operation sequences and procedures typical of Foundation Fieldbus systems. The simulation system is developed using LabVIEW with requisites of deterministic execution and a course management work frame web server called Moodle. The evaluation tests were conducted to verify the simulation performance as well as the system usability.

Análise do período de aquisição de uma variável de processo através de uma rede PROFIBUS DP: Comparação entre caso real e simulado

The PROFIBUS (Process Field Bus) DP is the most popular field bus communication used in the worldwide industry. Many factors contribute for its popularity: protocol simplicity and flexibility in baud rate, cable length and number of equipments by network. This flexibility causes huge acquisition time and reaction time variations for different network setups. This work shows an analog process variable acquisition time measurement in a real network and presents simulation network software that may used to plan different network configurations verifying acquisition time variations.

Students’ Evaluation based on Fuzzy Sets Theory

The traditional students’ evaluation method is a process designed to evaluate the qualitative aspects but, in fact, its final result is a grade that values the quantitative aspect. The challenge of this work is to consider a modifying, dynamic and coherent method of evaluation in the industrial automation area. Especially in the academic area, online laboratories are a commonly used distance learning model where the student practices the theoretical knowledge using a fieldbus simulator. These practical sessions can be performed in any location, as long as an authenticated, secure access is provided. At the Sao Carlos Engineering School, University of Sao Paulo (EESC/USP), a FOUNDATION FieldbusTM simulator named FBSIMU (Function Block Simulator) is being used as on online laboratory (Mossin, 2007). Engineering students can get involved with automation system technologies, as well as control theory, by implementing an application, therefore being able to explore and practice their knowledge. Considering the training and learning environment, it is important to implement a robust evaluation system to help teachers in the industrial automation area identifying students’ strong and weak points. The traditional evaluation method is a process designed to evaluate the qualitative aspects but, in fact, its final result is a grade that values the quantitative aspect (Rosa, 1999). Our challenge is to consider a modifying, dynamic and coherent method of evaluation. A graduated student in Automation must know the technologies related to programmable controllers, computer networks and manufacture automation. Besides these technologies, the student must also know how to configure and specify industrial communication systems, supervise instrumentation and control projects, identify control strategies in industrial processes, tune and optimize control loops in industrial processes, etc. Furthermore, there is a large amount of industrial protocols (FOUNDATION FieldbusTM HSE, FOUNDATION FieldbusTM H1, HART, PROFIBUS, DeviceNet, among others) available in the market and each one of those requires different particularities from the student. If we look at the traditional teaching method, even an excellent student in a certain area could fail the course and miss great opportunities for not having the formal education the teacher was ideally expecting. Regarding the inadequacy of the traditional method, this paper proposes the use of the fuzzy set technique that will be applied in the evaluation process of the industrial