This E book provides both fundamental and cutting-edge coverage on PLCs. It explains most basic to intermediate and advance instruction through many worked-out examples and explanations of the solutions. Since this is a self-teach manual, it is assumed that reader may not have any access to a PLC or instructor, to discuss any problems. Based on this assumption, the reader is familiarized with S7-200 Micro/Win software (Developed by Siemens Automation) to show the reader how the software could be used to edit, run and finally how to debug a program in hand. So, this is not just another programming book in PLCs. Two links are given in this EBook to download a simulator, and HMI editor. Both of these are going to be free software download that you can use them to familiarize yourself with how to use them. Good thing with Micro/Win software is that it does not require the use to have any PLC connected to a PLC. As soon as it starts, lets the user to edit a program and save it. With this simulator, you can test the logic of the program and actually see how input and output devices interact and how the whole program is functioning. A HMI simulator software allows you to edit a program and even test it offline from any PC connected to the HMI device. At the end, there are 25 complementary projects with worked out solutions (ladder logic programs) which is the method for you to test your programming knowledge. Lots of other examples are presented to show you how an instruction is used in practice.