PLC automation

What are the basic features and components in PLC Automation?

Nowadays, industrial PLC Automation systems are more complex and technologically aware than ever. However, they did not get to this point on their own!

They are supported by Programmable Logic Controllers (PLCs), which enable their internal components to work together as a single, integrated system. These digital computers, which are adaptable and easily customizable, are critical components of many of the methods and technologies we rely on today.

What is a PLC? 

Programmable logic controllers (PLCs) are industrial-scale devices with computer capabilities that regulate production processes in assembly lines, robotic cells, industrial machinery, and other manufacturing environments. Fault detection, excellent dependability, and programmable production control all use them. To handle inputs in such short periods, PLCs run in real-time. Timeliness is always a vital factor in achieving their control objectives. 

PLCs were introduced to replace hard-coded relay systems with more flexible programmable controllers some decades ago as the fundamental reason for their development. It was initially used in automobile production lines to enhance automation and dependability in industrial operations management.

PLC Basics

Dick Morley developed PLCs in 1964. Since then, PLC automation has transformed the manufacturing and industrial industries. Timing, counting, calculating, comparing, and processing analog signals are all PLC tasks.

After programming it with a PLC, you may update it, saving money (only the programmer’s time). Wires must be ripped out and new ones installed in hard-wired control systems (which is more expensive and takes longer). 

PLC automation may control more extensive and more sophisticated operations than this basic example. Unified Process Control (UPC) is a programmable logic controller (PLC).

Components in PLC Automation

  • Power Supply

Electrical distribution voltage (230 VAC, 120 VAC, or 125 VDC) is converted to signal level voltage for the plc processor and other modules in the power distribution centre.

  • Processor

The processor module houses the microprocessor that controls and computes, as well as the program memory.

  • Input/Output

These modules link the CPU to the field equipment. Analog input, analog output, digital input, digital output, etc.

Flow transmitters, pressure transmitters, control valves, analyzers, substation feeds for motor control, etc.

  • Communication

Modules are offer for a variety of industry-standard communication networks. Modbus communication cards or serial communication are the most prevalent modules. Rather than requiring separate modules, some PLCs include built-in communications.

  • Communication Protocols and Media 

Copper wire, coaxial cable, fibre optics, and wireless are the most popular communication mediums. Ethernet, Ethernet/IP, and DeviceNet are the most prevalent “open” communication protocols.

Open systems often have “plug and play” functionality, where the system software automatically detects and communicates with any attached compatible device.

This setup generally necessitates a redundancy module to give status and control confirmation between CPUs. Signal connection to redundant racks is also possible.

Advantages of PLC automation

  • It’s easier and faster to make modifications.
  • PLCs feature built-in diagnostics and override capabilities.
  • A wide range of diagnostics is available at the fingertips of all patients.
  • It is possible to document applications instantly.
  • It is easier and less expensive to re-create applications.


Industrial automation has lately gained widespread popularity across many sectors, owing to the numerous benefits it provides, including enhanced productivity, improved quality, and increased safety at a cheap cost.