Programmable Logic Controllers: An Introduction (ISBN 0750631198)

Good Book with many mistakes:
This is a great book for beginning PLC programmers, but there are numerouse errors throughout the book which cause confusion when trying to understand the use of Internal Relays, Timers and Counters. Use caution and refer back to the text when completing the tests at the end of each section and when reading about how some ladder logic is functioning, I noticed miss-labled Inputs.

Do not buy this book if youre programming STL:
I did not get any benefits of this book, sadly. It is useless with Siemens S7 and you want to learn the STL language. To few examples with this language. Sorry

Useful Information:
This book was full of usefull information, and it was laid out well. I was just disapointed by the lack of coverage of Allen Bradley controllers, which are the most widely used controllers in my area.

Some very good, some bad:
I bought this book to help bring me up to speed on PLCs. I have several years working in electronics and other engineering disciplines, but almost no system control experience. I did learn a few things from this book and it was helpful. However, there are some serious mistakes in the book. There are several details that are simply wrong, which makes this book a poor choice for people with little to no prior knowledge in the field.

A succinct but comprehensive introduction to PLCs:
Bolton does a great job with an intro to PLCs. The book is great for a comprehensive introduction to PLCs. I needed inexpensive, yet solid course material, for an adult ed course. This book has been perfect for providing easy to digest material for folks who need familiarity with PLCs.