This book gives an introduction to the programming language Structured Text (ST) which is used in Programmable Logic Controllers (PLC). The book can be used for all types of PLC brands including Siemens Structured Control Language (SCL) and Programmable Automation Controllers (PAC). This 3rd edition has been updated and expanded with many of the suggestions and questions that readers and students have come up with, including the desire for many more illustrations and program examples. CONTENTS: - Background, benefits and challenges of ST programming - Syntax, data types, best practice and basic ST programming - IF-THEN-ELSE, CASE, FOR, CTU, TON, STRUCT, ENUM, ARRAY, STRING - Guide for best practice naming, troubleshooting, test and program structure - Sequencer and code split-up into functions and function blocks - FIFO, RND, sorting, scaling, toggle, simulation signals and digital filter - Tank controls, conveyor belts, adaptive pump algorithm and robot control - PLC program structure for pumping stations, 3D car park and car wash - Examples: From Ladder Diagram to ST programming The book contains more than 150 PLC code examples with a focus on learning how to write robust, readable, and structured code. The book systematically describes basic programming, including advice and practical examples based on the author s extensive industrial experience. The author is Bachelor of Science in Electrical Engineering (B.Sc.E.E.) and has 25 years experience in specification, development, programming and supplying complex control solutions and supervision systems. The author is Assistant Professor and teaches PLC programming at Dania Academy, a higher education institution in Randers, Denmark.