The downy woodpecker is virtually identical in plumage pattern to the larger hairy woodpecker, but it can be distinguished from the hairy by the presence of black spots on its white tail feathers and the length of its bill.
A programmable logic controller, PLC, or programmable controller is a digital computer used for automation of typically industrial electromechanical processes, such as control of machinery on factory assembly lines, amusement rides, or light fixtures.PLCs are used in many machines, in many industries.LC applications are typically highly customized systems, so the cost of a packaged PLC is low compared to the cost of a specific custom-built controller design. On the other hand, in the case of mass-produced goods, customized control systems are economical.
A Programmable Logic Controller, or PLC, is more or less a small computer with a built-in operating system (OS).This OS is highly specialized to handle incoming events in real time, i.e., at the time of their occurrence. PLC is primarily used to control machinery. Programs written for PLCs consists in simple terms on instructions to turn on and off outputs based on input conditions and the internal program. In this aspect, it is similar to a computer.