Programmable Logic Controllers (PLCs) swept across the industrial world when they were first introduced to the market in the 1960s. Automation systems, manufacturing industries, and assembly mechanisms saw a rapid transformation in their performance and efficiency with the involvement of Programmable Logic Controllers.
Since the time of their inception, PLCs have gone through a lot of evolutionary phases which increased their performance and efficiency manifolds. In the initial years, PLC systems consisted of thousands of unique relay systems that worked in coordination in order to execute a specific work. Operating these relay control systems with motion control and timers was itself a complex procedure. However, as the electronic components got more compact with the advancements in technology, these relay controls were replaced by microprocessors. This in turn, not only enabled the workers to operate them easily, but also added the multifunctional feature in them; i.e. a single PLC could now perform multiple functions at a time.
What Are PLCs?
Programmable Logic Controllers, commonly referred to as PLCs, are basically digital computers that are exclusively designed to operate in a wide industrial line. Their design differs from general purpose computers as the control unit of PLCs is different in both design and functionality. Every PLC unit has its own design and function according to the requirements and input/output configurations. For example, a PLC designed for a car assembly factory would be different from a PLC which is installed in a company for automation purposes and the design of each system will be determined by a company experienced in custom control panels.
How PLCs Operate:
As mentioned earlier, the manufacturing design of modern PLCs is microprocessor based; hence, they are programmable. They are programmed using a specialized language in various logics, techniques, and standards, ranging from the C language to Basic, FBD (function block diagram), SFC (sequential function charts), ST (structured texts), IEC 61131-3 standard and the ladder logic. These programs are stored in the nonvolatile part of the memory section.
Programmable Logic Controllers operate according to the type of program fed in them. Programming standard or technique is chosen according to the complexity of the work they are set to do. The Logic ladder is considered as the most user-friendly technique. When the logic ladder logic is used, the system acts in the sequential modes. Sequential modes are most easy to work on and need basic technical knowledge to control the machine. That is why, even those who have little or no knowledge of computer operation, can easily work on PLCs programmed in ladder logic.
Impact On The Industry
The flexibility, cost-efficiency, and convenience has made PLC one of the most important parts of the manufacturing industry. It is one of the prominent factors in the global development in general and in the industrial development in particular.
One can gauge the impact of PLCs by thinking about the difference in the output and productivity when thousands of machines or human labor are replaced by a single machine that can perform multiple functions and control multiple things under a single program. Moreover, the ratio of errors in manual operations is mitigated to the minimum through these programmable machines. Apart from that, the monitoring and troubleshooting in these programmable machines are very easy. Industrial environment is pretty harsh for labor work, whereas PLCs can work perfectly normal in these tough conditions.
PLCs continue to become less spacious, more durable and cost effective with each passing day. Many programmable machines have already hit the market by storm which can be used in domestic chores. Considering the facts discussed above, it can be easily said that the days are not far when the Programmable Logic Controllers will replace most of human labor jobs.