This book gives an introduction to Structured Text (ST), used in Programmable Logic Control (PLC). The book can be used for all types of PLC brands including Siemens Structured Control Language (SCL) and Programmable Automation Controllers (PAC). Contents: - Background, advantage and challenge when ST programming - Syntax and fundamental ST programming - Widespread guide to reasonable naming of variables - CTU, TOF, TON, CASE, STRUCT, ENUM, ARRAY, STRING - Guide to split-up into program modules and functions - More than 90 PLC code examples in black/white - FIFO, RND, 3D ARRAY and digital filter - Examples: From LADDER to ST programming - Guide to solve programming exercises Many clarifying explanations to the PLC code and focus on the fact that the reader should learn how to write a stable, robust, readable, structured and clear code are also included in the book. Furthermore, the focus is that the reader will be able to write a PLC code, which does not require a specific PLC type and PLC code, which can be reused. The basis of the book is a material which is currently compiled with feedback from lecturers and students attending the AP Education in Automation Engineering at the local Dania Academy, "Erhvervsakademi Dania", Randers, Denmark. The material is thus currently updated so that it answers all the questions which the students typically ask through-out the period of studying. The author is Bachelor of Science in Electrical Engineering (B.Sc.E.E.) and has 25 years of experience within specification, development, programming and supplying complex control solutions and supervision systems. The author is Assistant Professor and teaching PLC control systems at higher educations. LinkedIn: https: //www.linkedin.com/in/tommejerantonsen/