Recent advances in LSI technology and the consequent availability of inexpensive but powerful microprocessors have already affected the process control industry in a significant manner. Microprocessors are being increasingly utilized for improving the performance of control systems and making them more sophisticated as well as reliable. Many concepts of adaptive and learning control theory which were considered impractical only 20 years ago are now being implemented. With these developments there has been a steady growth in hardware and software tools to support the microprocessor in its complex tasks. With the current trend of using several microprocessors for performing the complex tasks in a modern control system, a great deal of emphasis is being given to the topic of the transfer and sharing of information between them. Thus the subject of local area networking in the industrial environment has become assumed great importance. The object of this book is to present both hardware and software concepts that are important in the development of microprocessor-based control systems. An attempt has been made to obtain a balance between theory and practice, with emphasis on practical applications. It should be useful for both practicing engineers and students who are interested in learning the practical details of the implementation of microprocessor-based control systems. As some of the related material has been published in the earlier volumes of this series, duplication has been avoided as far as possible.

In racent years the LSI technology has witnessed a revoluti onary development, and allowed substantial reductions in the size and cost of digital logic circuitry. Computer system building blocks have progressed from the level of discrete components to the level of complex ICs involving many logic circuits on a single "chip". The invention and wide applica tions of microprocessors have changed the philosophy of the signal processing, measurement and control engineering fields. The microprocessor-based digital signal processing systems and controllers have replaced the conventional ones based on standard analog and digital computing equipment. The first microprocessors and "on-chip" computers have appeared towards the end of 71 beginning 72. Their evolution since then and the number of applications, in which they have been utilized, have both been extremely spectacular. New system concepts and hardware/software tools are steadily under development to sup port the microprocessor in its multiple and complex tasks. The goal of this book is to provide a cohesive and well-balan ced set of contributions dealing with important aspects and applications of microprocessors to signal processing, measu rement and system control. The majority of contributions in clude sufficient review material and present rather complete treatments of the respective topics.

The introduction of the microprocessor in computer and system engineering has motivated the development of many new concepts and has simplified the design of many modern industrial systems. During the first decade of their life. microprocessors have shown a tremendous evolution in all possible directions (technology. power. functionality. I/O handling. etc). Of course putting the microprocessors and their environmental devices into properly operating systems is a complex and difficult task requiring high skills for melding and integrating hardware. and systemic components. software This book was motivated by the editors' feeling that a cohesive reference is needed providing a good coverage of modern industrial applications of microprocessor-based real time control, together with latest advanced methodological issues. Unavoidably a single volume cannot be exhaustive. but the present book contains a sufficient number of important real-time applications. The book is divided in two sections. Section I deals with general hardware. software and systemic topics. and involves six chapters. Chapter 1. by Gupta and Toong. presents an overview of the development of microprocessors during their first twelve years of existence. Chapter 2. by Dasgupta. deals with a number of system software concepts for real time microprocessor-based systems (task scheduling. memory management. input-output aspects. programming language reqUirements.