Who is the Father of the PLC and Why was it invented?

You probably read these articles because of your interest in PLCs and automation. But have you ever wondered who actually invented the PLC, or how the first PLC came to be?

Today you will learn the story of Richard “Dick” Morley, commonly referred to as the Father of the PLC. Dick actually referred to himself as the father of the PLC instead of the inventor, you will find out why shortly.

Let’s think back to how logic in machinery worked before the PLC came into the picture. Logic was performed through electromechanical relays. A lot of older guys refer to this as click-clack logic because of the sounds the relays make as a machine would run.

The electromechanical relays would wear out or simply fail.

Not to mention the “rats nest” that wiring in those old cabinets would turn into after repairs were made or troubleshooting performed. Manufacturers were trying to become faster and more efficient. They were starting to look into solid state computers and devices for their controls.

In these early days of modern manufacturing, a young Dick Morley was just starting his engineering career.Morley attended about 4 years at MIT. While there he worked as a machinist.

After leaving MIT before graduating, Morley was drafted for the Korean War. This led to him working for a company called Lab for Electronics. There he worked on bombs, radar, and other electronics.

By the mid 1960s, Morley was a young engineer and had just started a small consulting company called Bedford Associates. He and his associates were working with machine tool firms helping them upgrade their facilities.

They were working mostly with microcomputers, slowly converting the machinery into solid state controlled machines.

While business was good, it was also pretty monotonous. Morley was starting to get fairly bored with the work. Each new job was relatively the same as the last.

On New Year’s Day of 1968, with a hangover, he was about two weeks late on another proposal and decided there had to be another solution.

Morley was fed up with the same old job time after time, and in that moment wrote down the specs for what would become the Programmable Controller. He had a clear idea of what he wanted the controller to be like.

First, he wanted no interrupts for processing. This means that nothing should be able to interrupt the program unless it is programmed to do so.

Second, he wanted direct mapping into memory. This would allow an easier way to program the data tables and information into the PLC.

Next, he wanted it to operate slowly. This, Morley would later regret.

Morley also wanted a rugged design that really worked in the industrial settings. It had to be completely sealed and cooled with well-engineered heat transferring.

He also wanted a language that would be proprietary to Bedford Associates. He wanted the exclusive rights to the language. This would lead to the development of ladder logic, and we know now that it is more of a universal language for technicians and engineers.

Once Morley had his memo written down with all of his specifications, he took it to his team at Bedford Associates, which included Mike Greenberg, Jonas Landau and Tom Boissevain. They soon got to work on designing the programmable controller.

One rule that Morley implemented is that the controller was NOT a computer. If he saw the word computer written on a document he would throw it away! Once they started building the controller, they made it rugged and durable with excellent thermal transfer ability.

It used big metal fins as heat sinks, and allowed no outside air into the unit.

The group named it the model 084 since it was Bedford Associates 84th project. The model 184 came soon after and worked out a few kinks and problems that were found in the 084 model.

To get the project off the ground and really going, the team had to find some financial backers to invest in the project.

The team decided to start a new company with the investment. They called it Modicon, short for Modular Digital Controller.

Modicon was incorporated October 24th, 1968. Morley was never technically an employee, however, he was in charge of engineering for Modicon.

While all of this was developing at Bedford Associates and Modicon, General Motors Hydramatic Transmission factory was looking to upgrade their facility with solid state controllers.

They were looking for a replacement to the less reliable relay logic machines that were standard at the time.

The fact that others were looking into a programmable controller, same as Morley, is the main reason he always referred to himself as the “Father” of the PLC instead of the “Inventor”.

General Motors eventually heard about the project going on at Modicon and ended up ordering One Million dollars worth of PLC’s from Modicon.

General Motors took delivery of their first batch of PLC’s in November of 1969. This was merely a year after Modicon was formed and really got started on the model 084.

Soon after General Motors, General Electric decided to order One Million dollars worth of the new Programmable Controllers. They wanted to label and sell them as their own OEM units.

Eventually, Bedford Associates dissolved to avoid tax issues after Modicon really took off. Modicon was eventually sold and is currently owned by Schneider Electric. They still occasionally use the number 84 on some of their products.

I hope this helps you understand a little about the early days of the PLC. The story of the Father of the PLC and the first PLC are very intertwined.

Dick Morley is a legend in the manufacturing and automation industries. Without Morley, The PLC would probably have been invented, just not nearly as fast or as well as it was. He claims that the Programmable Controller invented itself out of necessity and had 50 or more inventors.

Mr. Morley recently passed away in October of 2017. He was active in the automation and technology community pretty well until his passing.

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With endless love and gratitude,

The RealPars Team

PS: Please share your thoughts and ideas directly in the comments.

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