INTERNAL ARCHITECTURE OF PLC(programmable logic controller) In this blog, we will learn the basic internal architecture of PLC that includes CPU of PLC, different buses in PLC system then memory unit of PLC and input/output unit of PLC system. The internal architecture of PLC consists of the CPU which contains the system microprocessor, memory storage and other integrated circuits that are used to execute the control program and input output circuitry that communicate to external devices. Central processing unit control and processes all the operations within the PLC and it is supplied with a clock which has a frequency which is typically between 1 and 8 MHz and this frequency decide the operation speed of the PLC, which provides timing and synchronization for all the elements in the system. The information is carried out within the PLC is by digital signals that are in 1 and 0’s and these digital signals flow on internal paths that path are called buses. The b...