The History Of The Programmable Logic Controller (PLC): A Game-Changer in Industrial Automation

The Programmable Logic Controller (PLC), a cornerstone of modern industrial automation, revolutionized the way industries approach control systems. Emerging in the late 1960s, PLCS were designed to replace traditional relay logic systems in manufacturing environments, particularly in the automotive industry. Since their inception, PLCs have become an indispensable tool in automation, offering numerous advantages over earlier technologies.

Origins of the PLC: The Need for Innovation

The story of the PLC begins with General Motors (GM) in 1968. The automotive giant's Hydramatic division, responsible for automatic transmission production, sought an electronic solution to replace its hard-wired relay systems. At the time, relay-based control systems were cumbersome, complex, and prone to failure, requiring frequent maintenance and extensive hardware changes. GM's search for a more reliable, efficient solution led to a groundbreaking request for proposals (RFP) for an electronic controller.

Edward R. Clark, an engineer at GM, wrote a white paper that laid the foundation for the project. The winning proposal came from the Bedford Associates in Bedford, Massachusetts. This proposal led to the creation of the first-ever PLC, developed in 1969. This model, known as the 084, was Bedford Associates' 84th project. The PLC was designed to improve upon traditional relay systems by offering better reliability, compactness, and ease of maintenance.

The Rise of Modicon: The Birth of the PLC Industry

In the early 1970s, Bedford Associates established a company dedicated to the development, manufacturing, and servicing of their newly designed programmable logic controller, which they named Modicon (Modular Digital Controller). One of the key figures behind the development of the PLC was Dick Morley, widely regarded as the "father" of the PLC. Morley's innovation revolutionized industrial automation, leading to the widespread adoption of PLCs in factories across the globe.

In 1977, the Modicon brand was sold to Gould Electronics, and later acquired by Schneider Electric. The legacy of the first PLC, the 084 model, is now preserved and proudly displayed at Schneider Electric's North Andover plant in Massachusetts, where it serves as a symbol of the innovation that changed industrial control systems forever.

The Evolution of PLC Programming

Early PLCs used a trapezoidal logic programming approach, which closely resembled the schematic diagrams of traditional relay systems. This design choice helped ease the transition for technicians who were already familiar with relay logic, thus reducing the need for extensive retraining. Over time, PLC programming evolved to include instruction lists and various programming languages, allowing for more advanced and flexible control systems.

As PLC technology advanced, it became more user-friendly and adaptable. Modern PLCs feature simple programming languages that emphasize logic and switching operations, making them more accessible compared to general-purpose computer programming languages. Additionally, PLCs allow for real-time monitoring, providing operators with enhanced control and visibility of their systems.

(Our Advantageous Products：GE Fanuc IC695ALG600;GE Fanuc IC694DNM200;GE Fanuc IC695CPU310;Siemens 6ES7414-2XL07-0AB0;

Schneider 140ACO13000;Schneider Quantum 140CPU65160S;Allen Bradley 1757-SRM;Allen Bradley 1756-EN2TR;Allen Bradley 1756-PB75 and so on.)

The Role of Odo Josef Struger in PLC Development

In parallel to Modicon's developments, another important figure in the history of PLCs is Odo Josef Struger, sometimes referred to as the "father of the programmable logic controller." Struger was instrumental in the development of the Allen-Bradley PLC between 1958 and 1960. Struger is also credited with coining the term PLC, which would become a standard term in the industry. During his tenure at Allen-Bradley, now a part of Rockwell Automation, Struger helped guide the company's rise to prominence as a leading PLC manufacturer in the United States.

Struger was also a key player in the creation of the IEC 61131-3 standard for PLC programming languages, which continues to serve as the basis for modern PLC programming today.

A Legacy of Innovation and Efficiency

The development of the PLC has had far-reaching effects on the manufacturing and automation industries. PLCS provide industries with a reliable, flexible, and cost-effective solution for controlling and monitoring industrial processes. They allow for greater system reliability, reduced maintenance costs, and the ability to adapt to changes in manufacturing needs.

Today, companies like Schneider Electric and Rockwell Automation continue to lead the PLC market, offering advanced solutions for industrial control systems. These companies have built upon the foundational work done by pioneers like Morley and Struger, continuing to drive innovation in industrial automation technologies.

Conclusion: The PLC's Impact on Modern Automation

From their humble beginnings in the automotive industry to becoming an essential part of modern industrial automation, PLCs have proven to be a game-changer. The PLC has allowed manufacturers to streamline operations, reduce downtime, and improve overall efficiency. As industries continue to evolve, the role of PLCs will only become more significant, shaping the future of automation for years to come.

More Product Models

For more information, please contact Vicky--sales7@apterpower.com(Email)