Manufacturing AUTOMATION

The father of invention: Dick Morley looks back on the 40th anniversary of the PLC

June 12, 2009
By Alison Dunn

Manufacturing was changed forever because Dick Morley liked to ski.

The year was 1964, and Morley was a young engineer working nine-to-five at a desk job designing airplanes, atomic bombs and communications systems.

“I was the guy in the corner room that nobody ever came to see,” Morley recalls. “They just said, ‘design me an airplane, design me a radar or design me a better communication system.’ All of which I did.”

Morley’s friend, a man named Jonas Landau, made a keen observation. “Dick,” he told Morley, “you’ve got to change what you do. All you’re doing is being a computer for these guys and putting stuff out.”

“Yeah, but I like it,” Morley replied.


“Yeah, but you should get out a bit,” Landau advised.

That’s when Dick Morley had the wake-up call of a lifetime: He learned how to ski. And that is how the programmable logic controller was born.

No single invention has had as much impact on the manufacturing sector as the PLC. Invented in 1968 by Morley and a group of fellow “geeks,” the PLC allowed us to automate industrial process with multiple input/output arrangements in real time. With the ability to withstand extreme temperature ranges, electrical noise and vibration, it changed the way we automate our factories and is still widely in use today.

But how does Dick Morley’s love of skiing translate into the invention of a lifetime? We sat down with Morley on this, the 40th anniversary of the PLC, to look back at how it all began – and what the future holds for the next 40 years.

The beginning of Bedford
After suggesting that Morley get out a bit more, Jonas Landau took Morley out skiing for the first time. That ski trip was a bit of a revelation for Morley. He liked it, and he was pretty good at it too.

The only problem was that Morley wasn’t the only one who liked to ski. Much to his dismay, the ski hills were jam-packed on the weekends with other skiing enthusiasts. It got to the point that it made more sense to go skiing during the week, when fewer people were out on the hill. So the enterprising young engineer asked his employer if he could swap his workdays. He’d take Fridays off to ski, and work on Saturdays.

“I never talked to anybody at work anyway,” he says. “I talked to somebody once a week! But they said, ‘you can’t do that. It’s against the rules.’”

Morley made the decision of a lifetime. He quit his job so he could go skiing. He wasn’t looking to start his own company, or come up with the invention of a lifetime – he just wanted to get off the corporate hamster wheel.

But, of course, real life intervened. “I had a little baby, a mortgage, $1,000 in the bank and no possible thing to do,” he recalls. “I had nothing, but I wanted out. So I started a company.”

The company was Bedford Associates, so named because it was located in Bedford, Mass. Morley started the company with his friend George Schwenk, and the professional consulting firm worked with local machine tool firms to help them evolve into the new, solid-state manufacturing sphere.

But once again, monotony got to Morley. He noticed that each project was roughly the same; they were using small minicomputers, and there was a certain similarity from project to project. And, once again, he started to get bored. Was there a way he could create a controller that worked for every job?

The PLC is born–during a hangover
On Jan. 1, 1968, Dick Morley had a hangover. It was not an auspicious start to the day he would draft a memo that would lead directly to the invention of the PLC.

“The thing I remember most was the hangover,” Morley recalls. “I had a hangover because it was New Year’s morning. But I was already two weeks late on a proposal that was due on yet another system, and I thought, I’m tired of this! So instead of doing a proposal, I wrote down – honest to God, in that day – the entire programmable controller.”

Morley had a pretty clear picture of what he wanted this programmable controller to look like:
• No interrupts for processing
• Direct mapping into memory
• No software handling of the repetitious chores
• Slow (a mistake which Morley later realized)
• A rugged design that really worked
• Language (ladder logic came a few months later)

Morley took that memo to the team at Bedford, including Mike Greenberg, Jonas Landau and Tom Boissevain. Together, they worked on designing the unit that would be modular and rugged, using no interrupts. They called it the 084, since it was the 84th project for Bedford and Associates.

The mechanical and thermal design of the 084 made it stand apart from anything else any other company currently offered. It could withstand physical abuse, had no air inside and transferred air out through big metal fins so that no dirty air got inside to the electronics, meaning the device didn’t have to be in a sealed cabinet.

When the team was in the process of designing the unit, Morley and Schwenk had one rule: it wasn’t a computer. If somebody even wrote the word computer on a blackboard, Morley would erase the blackboard. If he found a piece of paper with the word computer written on it, he threw it in the garbage.

After finding some financial backers, the team decided to form a new company called Modicon, which stood for MOdular DIgital CONtroller. (Although Morley himself was never officially an employee on Modicon’s payroll, Bill Fletcher, Modicon’s first president, says Morley was in charge of engineering.)

Modicon was incorporated on Oct. 24, 1968, and worked closely with Bedford to create the controller. But were they the only ones? It turns out they had a bit of competition.

Modicon is “accidentally” in business
What the folks at Modicon didn’t know was that Bill Stone, with GM Hydramatic (the automatic transmission division of General Motors), presented a paper at the 1968 Westinghouse conference outlining his own problems with reliability and documentation for the machines at his plant. He wanted a solid-state controller as an electronic replacement for hard-wired relay systems.

The team at Modicon was finishing the design and build of the 084, which they were now calling the programmable controller, or PC. (The “logic” wasn’t added until the advent of the personal computer – also dubbed PC – in the early 1980s.) GM issued a request for proposals based on Stone’s paper, but Morley and the team were unaware that the paper existed.

The fact that others were looking to the idea of the PLC, and the fact that it was a group effort to create it, is why Morley, to this day, refuses to call himself the inventor of the PLC. He sees himself as the father of the PLC, rather than the inventor. “The programmable controller’s time was right,” he says. “It invented itself because there was a need for it, and other people had that same need.”

Plus, he adds with a laugh, “it was really invented by 50 people, each of whom invented half of it!”

As much as he jokes about it today, though, the need was pressing. The folks at GM heard about the work Bedford and Modicon were doing on the PLC, and contacted them about their project. GM ended up buying $1 million worth of PLCs, and, lo and behold, Modicon was in business.

“General Motors can accidentally buy enough to put you in business,” says former Modicon president Bill Fletcher. The 084 then gave way to the 184, which worked out some of the kinks of the original, and Modicon was off and running.

The growth of the PLC
General Motors took delivery of its first PLCs in November 1969. Then, General Electric came along and purchased another $1 million worth of units. “We agreed to sell them our units so they could change the labels and sell them OEM,” Morley says.

Modicon continued to grow, and the old guard started to move on to other projects. Bill Fletcher hired Don Kramer to take over the company, and Kramer oversaw the company’s growth and innovation over the coming years. Fletcher made a number of other successful hires as well, but there was just one thing he couldn’t replace.

“I didn’t do as well hiring people to take over the engineering functions,” Fletcher admits. “They were always in the shadow of Dick. He was such a powerful force – and still is – that is was very difficult for them to perform in that environment.”

Eventually, the success of Modicon caused the dissolution of Bedford Associates, to avoid tax issues. In 1977, Modicon was sold to Gould Electronics, and later to Schneider Electric, which still owns the brand today. In fact, Schneider still uses the Modicon name and even occasionally the number 84 for its PLC products. Dick Morley went on to start an incredible 110 more companies and become a noted speaker, author and father.

Today, the PLC is still used for control in almost every manufacturing facility in the world. Although there is some competition from PC-based controllers and DCS, the PLC still remains one of the most important automation inventions of all time.

Did anyone involved with the invention of the PLC have an inkling this would be the case? Yes, and no, says Fletcher.

“We were absolutely confident that we could design a much better way to do control systems,” he says. “But we didn’t say, ‘we’re going to be a $2 billion industry.’ As time went on, though, it became clear it was a very big deal.”

“I don’t really know how the programmable controller started,’ Morley adds, some 40 years later. “It really just grew by itself. You put the seed in, and the venture capitalist materialized and God – the marketplace – rained on it, and son of a gun, there it is.”

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