According to its introduction, this book has a modest objective. It was written to give technicians, engineering aides (consistently misspelled as “aids”), and engineers who know something about electricity and about an industrial process, a conceptual introduction to programmable controllers.

It meets that objective. It starts with basic topics (logic circuits, Boolean algebra, and binary numbers) and moves on to input/output interfaces and programming languages. It does not provide enough depth in any of these areas to be useful by itself. It provides enough in all of them for a reader to go on to other materials. Since that is its objective, it must be judged a success.

The book is clearly written and free of typos. It is short: just 139 pages of real text. The rest is taken up by manufacturers’ material--some reset, much reproduced from sales brochures. Also, the author’s lack of solid grounding in computer architecture and computer science shows. When he gets out of his area he makes several errors, such as equating baud rate to bits per second and defining a CRT (the molded glass display component of most monitors) as “a visual display terminal plus a keyboard.” While these may offend those who know better, and suggest that the publisher should get a technical reviewer for the third edition, they do not detract from the book’s overall usefulness to its intended audience.

The typical ACM member, and the typical reader of Computing Reviews, will not like (or need) this book. That person will find its relay ladder diagrams archaic, its computer technology below the threshold of usefulness (a big system has 256KB of memory), and its software toy-like. Yet those are the realities of the programmable controller world. The issues one faces in process control are as complex as those faced by computer scientists--but they are different, they would not interest most computer scientists, and this book does not go into them anyway.

If you need a feel for the real world of programmable controllers, and can keep your knowledge of computer science out of the way, you can get what you need here. Just do not expect much more.