Nunzio Torrisi

Modelling and evaluating traceability systems in food manufacturing chains

Traceability in food chains is mandatory in the near future for the most companies interested in food processing. Every food chain is made up of a variable number of companies. To realize a full traceability system we propose a distributed collaborative information system where every company exchanges traceability data with the others over a network. XML was used as the format to represent data, for its ability to cope with different size data structures. WebServices based technology has been adopted to interface different suppliers which communicate through HTTP protocol. A prototype has been implemented and evaluated. Access time is the performance index we chose to discuss in the paper because, considered the complexity of the traceability system and the scattering of the information, it represents a key factor for the users. The performances obtained on the testbed demonstrate the real applicability of this architecture in large production systems.

New operating modes for Bluetooth networks in distributed process control systems

The master/slave time division duplex approach implemented in the Bluetooth MAC sublayer simplifies management of the physical communication channel, but suffers from some limitations which prevent efficient bandwidth exploitation and may affect the overall throughput and message delays. These limitation have up to now prevented Bluetooth being extensively and successfully used in areas which differ from the traditional target applications this protocol has been developed for. We address these limitations and propose alternative slave/slave operating modes which enable Bluetooth to support new kinds of applications, such as the ones typical of distributed process control systems.

Design of a communication system for integration of industrial networks over public IP networks

The opportunity to integrate industrial automation applications from different cells over IP networks is a great advantage of such high level design over legacy proprietary data acquisition systems. The CyberOPC communication system is a research project in order to support and enhance all communications processes for manufacturing cells over Internet. That communication system was developed initially as variant of the OPC-XML data access specification with the aim to minimize the poll refresh time of the current OPC service communication system, simplify the Internet integration of low cost devices without the WebServices functionalities and provide CyberSecurity functionalities. We introduce in this work the CyberOPC communication system and propose the extension of the CyberOPC services with the device description services supported by an open and non-proprietary technology called Open-EDD with the goal to improve the integration and the process management of different shop floor distributed over public IP networks as Internet. The mains advantages of the proposed solution are: the performance of the CyberOPC Poll service; the simple integration with devices with the HTTP protocol support and the possibility to adopt the CyberOPC as transport system to manage remotely shop-floor services such as the device description service. The communication system proposed in this work represents an alternative technology for its performance and simplicity compared with the upcoming OPC-UA specification.

An open and non-proprietary device description for fieldbus devices for public IP networks

Open source communities today supply parallel technologies for operational systems like Linux instead Windows, for office tools like Open Office instead Microsoft Office, software development tools like Java instead DotNet, etc. The source code of that kind of product is available to be enhanced and any one can give opinions helping in the definition/implementation. This is the tendency of the software technology that can be also adopted to industrial area. Many people can contribute and the simultaneously, thus generating a product or technology with more attractive characteristics. This article presents a FOUNDATION fieldbustrade device description technology named Open-EDD, based on XML and other related technologies and its integration with CyberOPC, an open communication system for industrial devices over public IP networks.

Remote tuning of industrial controllers using CyberOPC technology

During the setup phase of an industrial plant and mainly during the maintenance phase, the tuning of industrial systems is executed. It enhances the performance of the industrial process during production life cycle. This paper focus on remote tuning applications and issues. The remote tuning approach supports several practical applications, such as specialized companies outsourcing services or companies distributed in different areas centralizing optimization. The developed software tool for remote tuning of open or closed PID control loops in an industrial environment fulfils the requirements described above, in a single platform. The transport technology CyberOPC supports the remote data update rate required using open technologies. The software tool could be used in control loops tuning in industrial systems, as well as in an academic environment simulating control applications and industrial networks.

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.

Remote-Tuning – Case Study of PI Controller for the First-Order-Plus-Dead-Time Systems

Control loop tuning today is the key factor for quality improvement and optimization of production costs. Simply replacing old systems with modern technology and networked equipment with high-processing capacity does not necessarily imply an improvement in product quality or an increase in plant productivity. However, according to researches conducted in the Industrial sector, most control loops in automatic operation have tuning problems (Harris et al., 1999; Ruel, 2003; Yu, 2006). Nowadays, systems that aid automatic tuning for control loops can be typically located at two levels in the automation systems hierarchy: they can be installed in the workstations, running together with software control systems and data acquisition or SCADA (Supervisory Control and Data Acquisition) systems; or they can be embedded within a distributed control equipment in the field, for example, in PLCs (Programmable Logic Controllers), smart transmitters, or DCS (Distributed Control System). When embedded, automated tuning systems are usually operated by an adaptive control where the controller’s parameters are continuously adjusted to accommodate changes and process disturbances. Tuning systems already installed in workstations are more advantageous than embedded systems due to their superior processing power and information storage. This characteristic leads to the development of more sophisticated algorithms, and provides additional resources, such as simulation and graphical analysis (Aström & Hägglund, 1995), (Ang et al., 2005). Remote access systems that use the Internet as the means of communication have become widespread in recent years, both in academic researches and industrial applications. Studies such as (Avoy et al., 2004) show great potential to growth and diversification of remote applications mainly in industrial environments. Among the advantages of remote access via the Internet in industrial applications, it is important to highlight: enterprises with distributed units can access, share, analyze and process plant floor information in real time and faster; and technical or specialized administrative services can be outsourced with a higher level of interaction between partners, thereby avoiding the need for experts in the staff. Studies in the Literature report proposals and systems for automatic tuning and dynamic control that use the communication via the Internet in different ways (Yu et al. 2006) (Yang