The document outlines a lecture on programmable logic controllers (PLCs) given by Behzad Samadi at Amirkabir University of Technology in Tehran, Iran. It discusses the history and origins of PLCs, their advantages over traditional relay-based control systems including reliability, flexibility and new capabilities like calculation and data processing. Programming methods for PLCs like ladder logic and function block diagrams are also covered. The document lists advantages and disadvantages of using PLCs and notes international standards that were developed for PLC architecture.