This book is an introduction to the programming language Ladder Diagram (LD) used in Programmable Logic Controllers (PLC).The book provides a general introduction to PLC controls and can be used for any PLC brands.With a focus on enabling readers without an electrical education to learn Ladder programming, the book is suitable for learners without prior knowledge of Ladder.The book contains numerous illustrations and program examples, based on real-world, practical problems in the field of automation.CONTENTS- Background, benefits and challenges of Ladder programming- PLC hardware, sensors, and basic Ladder programming- Practical guides and tips to achieve good program structures- Theory and examples of flowcharts, block diagrams and sequence diagrams- Design guide to develop functions and function blocks- Examples of organizing code in program modules and functions - Sequencing using SELF-HOLD, SET/RESET and MOVE/ COMPARE- Complex code examples for a pump station, tank control and conveyor belt- Design, development, testing and simulation of PLC programsThe book describes Ladder programming as described in the standard IEC 61131-3. PLC vendors understand this standard in different ways, and not all vendors follows the standard exactly. This will be clear through material from the vendor. This means that some of the program examples in this book may not work as intended in the PLC type you are using. In addition, there is a difference in how the individual PLC type shows graphic symbols and instructions used in Ladder programming.Note: This is a book for beginners and therefore advanced techniques such as ARRAY, LOOPS, STRUCT, ENUM, STRING, PID and FIFO are not included.