Unit II

Programmable logic controller (PLC)

A programmable logic controller (PLC) or programmable controller is a digital computer used for automation of electromechanical processes, such as control of machinery on factory assembly lines, control of amusement rides, or control of lighting fixtures. PLCs are used in many different industries and machines such as packaging and semiconductor machines. Unlike general-purpose computers, the PLC is designed for multiple inputs and output arrangements, extended temperature ranges, immunity to electrical noise, and resistance to vibration and impact. Programs to control machine operation are typically stored in battery-backed or non-volatile memory.
A PLC is an example of a real time system since output results must be produced in response to input conditions within a bounded time, otherwise unintended operation will result. This small controller, is the life in the industry because it is the charge to controll all the process there, through a progam language.

A programmable controller is a digital computer used for automation of electromechanical processes.

PLCs are used in many different industries and machines such as packaging and semiconductor machines.

Programs to control machine operation are typically stored in battery-backed or non-volatile memory.

A PLC is an example of a real time system.

This small controller, is the life in the industry.

It is the charge to controll all the process there.

Electromechanical: The technology of mechanical devices, systems, or processes which are electrostatically or electromagnetically actuated or controlled.
Packaging: Material used for making packages.
Semiconductor: An integrated circuit or other electronic component containing a semiconductor as a base material.

Legend.
Red: verb.
Blue:noun.
Yellow: pronoun.
Green: adjective.
Purple: adverb.
Bold: preposition.
Aquamarine: conjunction.


Source: http://en.wikipedia.org/wiki/Programmable_logic_controller