Programmable Logic Controllers

Rapid technological advances have made the PLC (Programmable Logic Controllers) an important part of many industries, from petrochemicals to food production. At the same time, the study of PLCs has moved into the lower academic levels - first year BSc/BEng modules, HNC/D and advanced GNVQ. This book provides an accessible introduction for all students on introductory courses in PLCs, with plenty of worked examples and programming problems designed to cover technology from a range of manufacturers. It has been written specifically for current courses, including the BTEC Advanced GNVQ Additional Unit in PLCs and the City & Guilds 230 course in Computer Aided Engineering. It is also designed as an introduction to the topic for degree students and engineers seeking to gain a working knowledge of PLCs.
This book aims to enable the reader to: identify the main design characteristics and internal architecture of PLCs; describe and identify the characteristics of commonly used input and output devices; explain the processing of inputs and outputs by PLCs; describe communication links involved with control systems; develop ladder programs for the logic functions AND, OR, NOR, NAND, NOT and XOR; develop ladder programs involving internal relays, timers, counters, shift registers, sequences and data handling; and identify methods used for testing and debugging.