What is a PLC (Programmable Logic Controller)? PLC is used to control the function of machine automatically. It is a computerized industrial microprocessor based controller that executes discrete or sequential logic in industrial environment. It was originally developed to replace mechanical relay, timer and counter hence it is also called industrial PLC. A PLC has an integrated programmable microprocessor that is programmed with a dedicated computer language (Ladder Diagram). After writing the PLC program it is downloaded to the non-volatile memory of Programmable Logic Controller directly through a cable connection via Serial or USB ports.
PLCs are somewhat similar to Microcontrollers…! i.e. user can write program using a computer and burn it in to the memory of microcontroller via a cable. Here CircuitsGallery providing you basic PLC training with PLC programming. You will be able to learn PLC automation, PLC controls and How to program PLC via our upcoming PLC programming courses in CG.

Difference between PLC and Microcontroller

  • PLC is mainly used for industrial applications, PLCs allow end user to organize and control the application which is more helpful in industries. Very complex controls and process like chemical industries requires more re-configurable controls.
  • Microcontroller design would be suitable where end user need not modify the controls eg: Automatic washing machine.
  • PLC programming is a type of graphical programming called ladder diagrams which are simple to understand, extremely easy and customized.
  • Microcontrollers are programmed using either Assembly language or C language. Compared to Ladder Diagram these are much complicated.
  • Trouble shooting is easier in PLC than microcontroller via online programming (we can see the real time working of PLC through computer).
  • PLCs are electrically based controllers but Microcontrollers are electronics based.
  • PLC module is costly as comparing with microcontroller, thus PLCs are commonly used in industries where as microcontrollers are applied in simple applications due its low cost.

Block diagram of PLC

Advantages of PLC

PLC has made a considerable role to Industrial automation. Former automation scheme had to use thousands of individual relays, timers and counters, which had to be rewired whenever we need a modification in the automated process. PLC permits all of the relays and timers within an industry to be replaced by a single controller. Present PLCs provide wide range of operations, including basic relay control, process control, motion control, and complex networking. They also be able to be used in a distributed control system (DCS).

Importance of PLC programmer

  • Attractive salary.
  • Easy to work with PLCs.
  • Easy to learn PLC programming (Ladder diagrams).

Keep visiting CircuitsGallery to become a PLC programmer…!

Applications of PLCs

  • PLCs have wide range of industrial applications, it is applied in
  • Process Industry.
  • Automotive Industry.
  • Energy Monitoring and load Shedding.
  • Oil & Gas Industry.
  • Petro – Chemical Industry.
  • Water Treatment Plant Etc.

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  1. I am in need of the programming software for the tablet (android os) to program pic 16f877 based PLC using otg cable. Pl. help. l am using a JDM serial programmer for my desktop PC.

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