Since the first edition of this book in 1988, the capabilities of programmable
logic controllers have grown by leaps and bounds. Likewise, the applications
of PLCs have grown with them. In fact, in today’s increasingly computercontrolled
environment, it is almost impossible to find a technical industry
that does not use programmable controllers in one form or another. To
respond to these phenomenal changes, we introduce the second edition of
Programmable Controllers: Theory and Implementation.
This second edition, like the first, provides a comprehensive theoretical, yet
practical, look at all aspects of PLCs and their associated devices and systems.
However, this version goes one step further with new chapters on advanced
PLC topics, such as I/O bus networks, fuzzy logic, the IEC 1131-3 programming
standard, process control, and PID algorithms. This new edition also
presents revised, up-to-date information about existing topics, with expanded
graphics and new, hands-on examples. Furthermore, the new layout of the
book—with features like two-tone graphics, key terms lists, well-defined
headings and sections, callout icons, and a revised, expanded glossary—
makes the information presented even easier to understand.
This new edition has been a labor-intensive learning experience for all those
involved. As with any task so large, we could never have done it alone.
Therefore, we would like to thank the following companies for their help in
bringing this book to press: Allen-Bradley Company—Industrial Computer
Group, ASI-USA, B & R Industrial Automation, Bailey Controls Company,
DeviceNet Vendors Association, ExperTune Software, Fieldbus Foundation,
Hoffman Engineering Company, Honeywell—MicroSwitch Division,
LANcity—Cable Modem Division of Bay Networks, Mitsubishi Electronics,
Omron Electronics, Phoenix Contact, PLC Direct, PMC/BETA LP, Profibus
Trade Organization, Schaevitz Engineering Company, Siemens Automation,
Square D Company, Thermometrics, and WAGO.
We hope that you will find this book to be a valuable learning and reference
tool. We have tried to present a variety of programmable control operations;
however, with the unlimited variations in control systems, we certainly have
not been able to provide an exhaustive list of PLC applications. Only you,
armed with the knowledge gained through this book, can explore the true
limits of programmable logic controllers.