Alfonso Blesa

Analysis and implementation of the IEC 61131-3 software model under POSIX Real-Time operating systems

Abstract In this paper, we present a proposal to implement the IEC 61131-3 software model. This model establishes the high-level elements of the Programmable Logic Controllers. We discuss some of the points of the standard that should be clarified before implementing it, such as concurrency, variable scope and cyclic operation. We show the implementation guidelines using POSIX compliant Real-Time Operating Systems, in particular RTLinux running on PCs. A translator has been implemented accepting textual descriptions following the IEC 61131-3 standard.

IEC 61499 execution model based on life cycle of function blocks

Current challenges of the manufacturing industry are related to the Agile Manufacturing paradigm. IEC 61499 standard has been adopted as the standard for flexible and reconfigurable control systems by this paradigm. Due to different reasons, this standard has not been adopted by industry yet. For example, as a result of some ambiguities in the standard specification, the proposed implementation models allow different semantics. So, it makes design and portability of applications developed difficult. This paper proposes an execution model based on life cycle of function blocks which clearly determines the system behaviour at design time and also facilitates an easier implementation.

Communication types for manufacturing systems. A proposal to distributed control system based on IEC 61499

The International Electrotechnical Commission (IEC) has defined the standard IEC 61499 for the next generation of distributed control systems used in agile manufacturing systems. This work identifies and characterizes different types of communications needed for distributed control. It simplifies application designers work and middleware implementation for the standard. Then, a proposal is presented for a distributed system based on a FB model and the types of communication identified and it is evaluated in a real application.

COSME: A distributed control platform for communicating machine tools in Agile Manufacturing Systems

Distributed control for Agile Manufacturing Systems (AMSs) is an active research field. Many efforts are focused on the IEC 61499 standard, although there is still work to be done for its adoption by the industry. A part of this work is related to solve its semantic ambiguities derived from implementation-dependent issues. This paper presents the COSME platform, which uses an adapted component model, a specific execution model and a set of communication types for the distributed control of communicating machine tools in the context of Agile Manufacturing Systems. These models can be expressed in IEC 61499 terms. This adaptation facilitates application designing and implementation.

Quality in the design and development of digital electronics practical tasks

The paper describes the use of two classical ‘Tools of Quality’ in digital electronics practical tasks, which allow the detection and continuous improvement of the educational method. Students obtain a work methodology which is based on quality and rigour, and which can be applied in their professional future.

“Predictive maintenance surveyor” design pattern for machine tools control software applications

Software involved in modern control applications is becoming increasingly complex, having to deal with newer and more sophisticated responsibilities. It must be now considered as a very relevant part in the mix of the system complexities and, unfortunately maybe very often, it is also an important source of engineering headaches. Its specific particularities should be conveniently taken into account using common software techniques. Design patterns are one of such techniques, widely used in the software world. The presented design pattern suggests a way to handle predictive maintenance, a service oriented to machine tools containing parts that suffer progressive deterioration which can be indirectly detected. This way, adequate maintenance actions can be scheduled just in time to avoid further problems development.

Control design for machine tools using Domiciano, an IDE based on software components

Nowadays, control software is increasing its complexity due to the need to attend diverse kinds of functional and extra-functional concerns. Therefore, it is necessary that the designer has adequate tools to manage this increased complexity. This work describes, as an industrial practice example, the Domiciano IDE. It allows developing control applications for the COSME platform (based on software components) shorting development times. TUROMAS group, a machine tool manufacturer for glass handling, cutting and storage, uses Domiciano to design its control software.

Control software design for a cutting glass machine tool based on the COSME platform. Case study

This work presents a case study showing the design of a glass cutting machine tool. This design is the first technological demonstrator of the COSME platform, its guidelines and tools. It represents an approach to simplify the design of control software in the manufacturing context, allowing to shorten time-to-market and aggregating value-added features.

Function blocks for the design of control applications based on EtherCAT fieldbus

Ethernet based fieldbus systems have been successfully introduced into industrial automation, and they are included on modern designs that demand features of conformance and integrated development. Function Blocks (FBs) allow encapsulating different levels of complexity, so that the control engineer can use these kind of buses, hiding some of these levels. This paper illustrates the advantages of FBs through a case of study, based on IEC 61499 standard, and supported by COSME platform. These advantages are: 1) easy design of complex systems by means of a network of function blocks; 2) easy evolution of a design by the change of a technology. In this case, the change is the introduction of the EtherCAT field bus. To do that, new FBs needed for the design are presented.

Pilot tutorial project as a quality action

Aims to show that quality concepts can be used in a real university world case by teachers who are voluntarily charged with the task of developing a program designed for helping new students. The first step toward considering the analysis of a previous experience has been taken – the First Action – that took place during the scholar year 1999/2000 at the University of Zaragoza. The results have shed some light on the difficult nature of the relationship between teachers and new students, and have persuaded the teachers of the centre to design an innovative plan considering the perspective of the philosophy of quality coming from the university‐society relationship: the Pilot Tutorial Project. Concludes that it is quite likely that significant improvements in our university work can be achieved by adopting the philosophy of quality.