Improved PWM A/D conversion technique: working principle and model validation

Analog-to-digital conversion plays a central role in any application of digital sensors and sensor systems that require an interface between analog devices, namely analog sensors, and digital devices, namely, microprocessors, digital signal processors or microcontrollers. With the advent of smart sensing, the integration of signal conditioning, analog-to-digital and digital data processing in single hardware devices became a reality. Moreover, the usage of low-cost discrete A/D conversion techniques for applications that are not critic in terms of accuracy, resolution or conversion rate, are considering increasingly mixed hardware and software A/D solutions tailored for specific application demands. In this context, this chapter presents a discrete low-cost A/D conversion solution based on pulse width modulation particularly suited for microcontrollers' integration with smart sensing devices.info:eu-repo/semantics/publishedVersio

Foundation fieldbus : from theory to practice

This paper describes the main characteristics of the Foundation Fieldbus (FF) technology considering both communication levels, namely H1 and H2, which have bit rates of 31.25 K and 100 Mbit/s, respectively. Several details about the physical layer, communication stack and user layer will be highlighted. Topics related with the configuration of instruments, as well as the design and implementation of supervision software, based on a LabVIEW interface, will be presented. A pilot plant that includes temperature, pressure, level and flow variables will be used to test and validate the capabilities of FF systems. Experimental results will be analyzed, their meaning discussed and the overall performance evaluated

Balanced Scorecard: A Powerful Method to Improve the Management of Educational Institutions

Trabalho apresentado em 2nd International Academic Conference on Teaching, Learning and Education (TLE 2020), Novembro 2020; Munique, AlemanhaTeaching, learning and education are the main activities related with any higher education institution (HEI), be they public or private. In this context, the balanced scorecard (BSC) is a powerful method that helps the successful application of performance measurements in terms of the efficiency of the programs, processes and people of any educational institution. The key performance indicators (KPI) are crucial indicators to translate the strategy into action, improving the synergies of all the people that contribute to management success. This paper underlines the importance of the BSC model in private, governmental and non-profit organizations highlighting its implementation in a HEI. In order to clarify the main concepts of the application of the BSC method in a HEI, a hypothetical institution (IPX) is considered and a set of strategic objectives are considered in terms of financial, clients, business, learning and growth perspectives. The key parameter indicators and the action plan are defined according to the HEI vision.info:eu-repo/semantics/publishedVersio

Transducer Electronic Data Sheets: Anywhere, Anytime, Anyway

Transducer electronic data sheets (TEDS) are a key element of smart transducers because they support core features such as plug and play, self-calibration, and self-diagnostics. The ISO/IEC/IEEE 21451-4 standard defines templates to describe the most common types of transducers and suggests the use of one-wire memories to store the corresponding data. In this paper we explore new ways to store and access TEDS tables, including near field communication (NFC) tags and QR codes. We also present a mobile TEDS parser, compatible with Android, that is capable of reading TEDS data from all supported mediums (one-wire memories, NFC tags, and QR codes) and decoding them as human-readable text. The idea is to make TEDS available in the easiest way possible. We also underline the need to extend the 21451-4 standard by adding support for frequency–time sensors. A new TEDS template is proposed, and filling examples are presented. The main novelties of the paper are (i) the proposal of new ways to store 21451-4 TEDS tables using NFC tags and QR codes; (ii) the release of new tools to access TEDS tables including a mobile parser; and (iii) the definition of a new TEDS template for frequency–time sensors.info:eu-repo/semantics/publishedVersio

IEEE 1451.1 Standard and XML Web Services: a Powerful Combination to Build Distributed Measurement and Control Systems

In 2005, we presented the NCAP/XML, a prototype of NCAP (Network Capable Application Processor) that runs under the .NET Framework and makes available its functionality through a set of Web Services using XML (eXtended Markup Language). Giving continuity to this project, it is time to explain how to use the NCAP/XML to build a Distributed Measurement and Control System (DMCS) compliant with the 1451.1 Std. This paper is divided in two main parts: in the first part, we present the new software architecture of NCAP/XML (which suffered some changes since the first version), and secondly, we describe the network configuration of a Web-enabled DMCS, which includes several NCAP/XML stations, a database and a Web Server

Next Generation Application Processor Based on the IEEE 1451.1 Standard and Web Services

Over the last decade, the 1451.1 Std has been a reference model to develop smart and open distributed measurement and control systems. Now, that the 1451.1 Std is about to be revised, there is the opportunity to enrich it with emergent and successful technologies as is the case of Web Services. Following this idea, we present a prototype of Network Capable Application Processor (NCAP) that runs on the .NET Framework and exposes its functionality through a set of Web Services. The prototype takes advantage of three key technologies: (i) the abstraction layer proposed by the 1451.1 Std; (ii) the interoperability provided by Web Services; and (iii) the productivity supplied by the .NET Framework

Using a Commercial Framework to Implement and Enhance the IEEE 1451.1 Standard

In 1999, the 1451.1 Std was published defining a common object model and interface specification to develop open, multi-vendor distributed measurement and control systems. However, despite the well-known advantages of the model, few have been the initiatives to implement it. In this paper we describe the implementation of a NCAP – Network Capable Application Processor, in a well-known and well-proven infrastructure: the Microsoft .NET Framework. The choice of a commercial framework was part of our strategy: to take advantage of several “of the shelf” technologies and adapt them to produce a NCAP prototype, called NCAP/XML. In addition, a solution to enhance the 1451.1 Std is presented by proposing a new format for inter-NCAP communication based on XML (eXtended Markup Language)

Performance Evaluation of a Web-Service-Based DMCS

The paper describes a set of experiments conducted on a service-oriented middleware infrastructure in order to evaluate its performance and applicability in the context of Distributed Measurement and Control Systems (DMCS). The infrastructure, entirely based on Web Services, was built using the Windows Communication Foundation (WCF), a software package released by Microsoft to develop distributed applications. The experiments were performed on a real plant equipped with all the instrumentation needed to run control loops for pressure, level, flow and temperature, quantities widely found in the process industry. The work focus on measuring the time delays associated with control loops and remote calls. The methodology of each experiment is described, results are presented and conclusions are drawn

A Piezoelectric Device for Measurement and Power Harvesting Applications

Com o apoio RAADRI.With the fast growth of wireless communications between nodes/sensor units, devices installed in remote places require power energy supply solutions to assure their functionally and data communication capabilities. For these applications energy harvesting takes place as a good solution, to increase the availability of energy, in opposition to the conventional systems of energy supply. Regenerative energy sources like thermoelectric, magnetic, piezoelectric, and/or renewable sources such as photovoltaic, wind, among others, allowed the development of different powering solutions for sensor units. The purpose of this work is to characterize a piezoelectric device to measure and capture mechanical vibrations from equipments, structures and piping vibrations, as well as from other sources. The study is carried out taking into account the power supply capabilities of piezoelectric devices as a function of the amplitude and frequency of the vibration stimulus, as well as, the electrical characteristics of the load circuit

Open Controller for Distributed Instrumentation Systems

The paper presents a controller designed to be highly interoperable in the context of distributed instrumentation systems. Interoperability is achieved by adopting strong standards – the IEEE 1451.1 Std to be more precise – and by using cross-platform, manufacturer-independent technologies such as Web Services. The 1451.1 Std contributes with its information model to represent data and organize functionalities through a well-defined hierarchy of objects. Web Services are used to implement both communication models, the client/server model for one-to-one communications, and the publish/subscribe model for one-to-many communications. Being supported by all the major software companies around the world, Web Services have the chance to become the first wide-used middleware solution and the answer for many interoperability problems. The controller was developed using the .NET Framework and tested in the Windows XP operating system