ROLE OF AUTOMATION IN TODAY’S INDUSTRIAL ERA

In recent years industrial world has undergone a significant transformation in terms of technical innovation and development. Today every industry (process, manufacturing, engineering, automotive, metallurgy etc) requires automation in any form to run its system smoothly and efficiently. Various industries in Pakistan are now making themselves abreast with the modern automation technology in either PLC or SCADA systems form to ensure smoother and reliable operations as well as to eliminate the ghost faults, easy troubleshooting, smooth operations and process inefficiencies. 

There are two main types of automation systems currently being used worldwide PLC and SCADA systems. Although SCADA is still difficult to implement due to its very high cost and scarce skilled engineers and electricians but PLC systems are now deployed in most of the automated industries, plants and processes and are running successfully throughout the country.

PROGRAMMABLE LOGIC CONTROLLERS (PLC)

PLCs are widely used in technological and industrial sector today. PLCs are modular solid state computer with custom programming. PLC is used in industrial control systems for machinery in a wide range of industries, including many of those involved in critical infrastructure. It is replacement of old day’s mechanical relay, timers and counters i.e. mechanical based systems. Before the PLC, control, sequencing, and safety interlock logic for manufacturing automobiles was mainly composed of relays, cam timers, drum sequences, and dedicated closed loop controllers. Since these could number in hundred or even thousands, the process of updating such facilities for the yearly model change-over was very time consuming and expensive, as electricians needed to individually rewire relays to change the logic. PLCs are used successfully to execute complicated control operations in a plant. A sequence of instructions is programmed by the user to the PLC memory and when the program is execute, the controller operates a systems to the correct operating specification as per the program logic.

It incorporates three basic features of input, process, and output where everything has to go along well and harmoniously. The input or data should go along with the suitable operation or process in order to produce the intended result or output.

BLOCK DIAGRAM OF PLC SYSTEM:

The PLC receives information from connected sensors or input devices, processes the data, and triggers outputs based on pre-programmed parameters.
Depending on the inputs and outputs, a PLC can monitor and record run-time data such as machine productivity or operating temperature, automatically start and stop processes, generate alarms if a machine malfunctions, and more. Programmable Logic Controllers are a flexible and robust control solution, adaptable to almost any application.

• I/O – The PLC’s CPU stores and processes program data, but input and output modules connect the PLC to the rest of the machine; these I/O modules are what provide information to the CPU and trigger specific results. I/O can be either analog or digital; input devices might include sensors, switches, and meters, while outputs might include relays, lights, valves, and drives. Users can mix and match a PLC’s I/O in order to get the right configuration for their application.

• Communications – In addition to input and output devices, a PLC might also need to connect with other kinds of systems; for example, users might want to export application data recorded by the PLC to a supervisory control and data acquisition (SCADA) system, which monitors multiple connected devices. PLCs offer a range of ports and communication protocols to ensure that the PLC can communicate with these other systems.
• HMI – In order to interact with the PLC in real time, users need an HMI, or Human Machine Interface. These operator interfaces can be simple displays, with a text-readout and keypad, or large touchscreen panels more similar to consumer electronics, but either way, they enable users to review and input information to the PLC in real time.