What is PLC?

A Programmable Logic Controller (PLC) is an electronic device that takes input from the plant / machine via sensors and transmitters, executes the logic programmed in its memory and generates the useful outputs on actuators to control plant / machine.

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.


basically plc is a control system which can control various types of processess like batch,continious and other mmanufacturing system through computerised system.The system reduces manula efforts and has more accurate outputs based on engineering algorithems

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PLC is not a control system, it may be programmed to perform control action by integrating PID module.

  • PLC is ultimately device used for data acquistion, data manipulation and computation purpose which provides output for particular input.
  • It is an industrial computer which takes input from sensors, limit switches & other relevant input devices and produces output to drive output devices like motor, lamp, relay & other output devices. But the output is dependent on ladder logic programmed in PLC.
  • If we talk about controller it’s all about ON/OFF,Multi-level, P, PI & PID.
  • Never says PLC/ microcontroller/ micro processor is controller they are used for data aquistion purpose only.
  • Moreover it is not an electronic device, more accurately you can say it is integrated with electronic components like op to-couplers, microprocessors, bridge rectifiers and others such.

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PLC is the abbreviation for Programmable Logic Controller. It is basically a hardware controller that has some specific instruction programmed into it via software programs such as Allan Bradley RSLogix Start Lite to produces some outputs to control equipment such as traffic lights, conveyors and other controlled outputs in the field. It is a very useful skill to acquire especially if you are a technologist in Instrumentation and Automation.


Free PLC Courses

A PLC is electronic equipment that senses inputs and takes the decision to change outputs according to the set rules/logic stored in the memory.

It is primarily an electronic controller, housed in industrial housing, which has logic programming function and can be an interface to industrial devices.