John R. Hackworth, Frederick D. Hackworth, Jr.
PROGRAMMABLE LOGIC CONTROLLERS: Programming Methods and Applications
Hard cover, pp. 303, plus XIII $41,99
Prentice Hall, Pearson Education, Inc.
Upper Saddle River, NJ 07458, 2004
ISBN 0-13-060718-5
http://www.pearsoneduc.com

In general about the book

With rapid advent of automation, most modern industrial plants have several hundreds of automatic control loops. The selection of the best control system for an application largely depends on the type and complexity of the application. The complexity of an application is dependent on many factors such as the topology of the plant, the number of different products, the criticality of the application, and the size of the plant.

Programmable logic controllers (PLCs) are well suited as logic controllers capable of proportional integral derivate (PID) control. As a device with multiple inputs and outputs, which contains an alterable program, the PLC is used both to control binary and/or discrete logic or sequencing functions and to provide continuous control functions. PLCs are primarily intended to replace hardwired electromechanical relay logic circuits and timers used in manufacturing automation. Today, PLCs are used in many industries including machining, packaging, material handling, automated assembly, and countless others.

This book is intended to offer a basic knowledge of the subject, which will enable the reader to progress rapidly to different types of PLC applications and programming techniques. It is divided into twelve chapters, two appendices, Bibliography, Glossary and Index. The book comes with CD-ROM that includes TRiLOGI software to accompany PLCs. The details of each chapter are as follows:

Chapter content

Chapter 1 deals with description of some of the fundamental components and their symbols used in ladder diagrams (LDs). After this the authors cover details related to realization of logical operations by LDs, and some more complicated circuits. Chapter 2 briefly introduces various types of PLC structures and points to the way in which a PLC executes a program. Chapter 3 gives an introduction to PLC programming. A graphical programming method is involved. For representation of relay coils and contacts it uses schematic symbols. Chapter 4 concentrates on advanced programming techniques that allow the system designer to realize more powerful and flexible solution in respect to hard-wired relay logic. Chapter 5 is concerned with the usage of mnemonic PLC programming language A principle of translating the LD into mnemonic code is discussed. Chapter 6 is devoted to specifics of connecting different types of: a) sensing devices and switches; and b) output controlled devices (lamps, motors, and contactors), to the PLC. Chapter 7 considers briefly some common problems encountered with the addition of analog input- output to the PLC system. Chapter 8 covers principles of operation of the most commonly used discrete position proximity sensors (inductive-, capacitive-, ultrasonic-, and optical-proximity sensors). Chapter 9 presents three types of devices; the encoder that senses a physical parameter and converts it to digital word; a transducer that converts one physical parameter into another; and a sensor as a device that senses the physical parameter and provides a discrete output. In Chapter 10 various methods of controlling a closed-loop system as well as the advantages and disadvantages of each are discussed. Chapter 11 looks at some of the more common and popular way of controlling ac and dc motors. In Chapter 12 problems related to provision of system integrity and system safety are treated. In order the system works well and safely, tools and procedures available to the designer are discussed.

In Appendix A logic symbols are given, while in Appendix B industrial electrical symbols are presented.

Useful book for undergraduate

The general organization of the book is reasonable in both terms of overall coverage and chapter headings. Each chapter includes objectives, an introduction, a central part, a summary, and review of questions. The text can be used for one semester undergraduate course. It is well-suited text for an introductory course for electrical engineering students with a major interest in control systems.

In summary, the book is a well-written source for fundamental concepts and methods in the area of designing control systems based on PLCs, and prepares the reader for further reading in the literature associated with this subject.