Programmable logic controllers (PLCs) have been used extensively and are offered in terms of functions, program memories, and the number of inputsoutputs (IOs), ranging from a few to thousands. With a focus on how to design and implement a PLC, this volume explains hardware and associated basic concepts of PLC. Authors have used PIC16F1847 microcontroller with: 8192 words of Flash program memory, 1024 bytes of SRAM data memory, 256 bytes of EEPROM data memory, the maximum operating speed of 32 MHz, 16-level deep hardware stack, an enhanced instruction set consisting of 49 single-word instructions.