Historical Engineers: Richard Morley and the Programmable Logic Controller (PLC)

October 15, 2018 by Gary Elinoff

Richard Morley is credited as the person who helped modernize industrial facilities with the invention of the programmable logic controller. Learn about his career, accomplishments, and contributions to the field.

Richard Morley is credited as the person who helped modernize industrial facilities with the invention of the programmable logic controller. Learn about his career, accomplishments, and contributions to the field.

Richard Morley was born on a farm in Clinton, Massachusetts in 1932. While he was reportedly not very motivated in high school, he amazed everyone with his acceptance to the prestigious Massachusetts Institute of technology. His boredom with academic life continued and, by his own admission, he was more interested in pulling pranks, running a bootleg AM radio station, and in his part-time job as a machinist. Despite some formal education at MIT as a mechanical engineer, he left school without a degree. 

By all accounts, regular corporate employment didn’t suit him. Uninterested in meetings and office politics, he preferred going skiing during the week because the lift lines were shorter. He found the life of a consultant more suitable than that of a 9 to 5’er, so he started his own company, Bedford Associates.

Neither his lack of degree nor distaste for corporate life proved to be much of a handicap. Over the next ten years, Morley was involved in the creation of the floppy disk, as well as a dazzling array of projects including radar, atomic bombs, and packet radio.

But what earns Morley the most fame in the electronics industry is his largest contribution: the programmable logic controller or PLC.

The Time Before Programmable Logic Controllers 

Although it’s hard to imagine it today, factories weren’t always controlled by computers. Machines still needed to be turned on and off in the proper sequence and the same machines had to respond to other events, such as overheating tanks and excess pressure in valves. In those benighted times, banks of relays and other electromechanical controllers were employed to do the job.


1960s-era manual relay panels. Image used courtesy of Lunds Universitet.


These old-time controllers were troublesome, requiring constant maintenance, and they consumed lots of power. And, perhaps worst of all, any changes in the manufacturing process, let alone the need to produce a different product, required the time and effort of skilled electricians to go in and rewire, by hand, each electrical connection between the relays, sequencers, and timers.

The Gauntlet Is Thrown: The Need for a "Standard Machine Controller"

In 1968, an engineer from GM Hydramatic named Bill Stone presented a paper at a Westinghouse conference laying out the challenges that he came across at his plant. He described a need in the industry from actual experience and submitted that a modular, rugged system was necessary for reducing downtime.

Several companies answered the call—including Allen-Bradley, Digital Equipment Corporation, and Century Detroit—putting forth early iterations of PLCs.

What Stone could not have known was that Morley and his company had already been designing such a device.

Enter Modicon

Dick Morley was already on the case. In January of 1968, Morley sketched out the parameters of the first PLC: a rugged, usable controller that could utilize direct mapping into memory and didn't require interrupts for processing. His initial design predated ladder logic by several months, though he apparently had already anticipated the need for that kind of language. Morley and his compatriots at Bedford Associates—Mike Green, Tom Boissevain, George Schwenk, and Jonas Landau—developed the idea of a Modular Digital Controller, which quickly got shortened to MODICON. 

The idea soon grabbed a lot of attention—so much so that Bedford Associates renamed itself Modicon in October of 1968.

The concept was initially rechristened the PC or programmable controller (as the "logic" portion would come with the advent of ladder logic). The first such device produced, the Modicon, was the Modicon 084.


The Modicon 084. Image used courtesy of Lunds Universitet.


The PLC was a big change for the factory floor, both technologically and culturally. It took the better part of a decade to gain widespread acceptance.

A self-described “lousy manager”, Morley wasn’t interested in running companies. He preferred to find people with interesting ideas and simply fund them and as such considered himself an “angel investor”. And, to hear him describe it, it seemed like he was always more interested in having techy fun than in actually making money.

In his later years, Morley moved to New Hampshire and ran another consulting company out of a facility he called “The Barn”. He’d been married to his wife, Shirley, for half a century and they raised three of their own children and fostered over twenty.

Richard Morley passed in 2017 at the age of 84. His legacy can be seen in industrial control around the world.



Were you one of the engineers whose life was changed when the PLC was introduced? Please share your recollections of that time period in the comments below.



Featured image used courtesy of Elmschrat Coaching [CC-SA 3.0]

  • babajim October 22, 2018

    It was sometime around March of 1971 that Jim Stott, the Electrical Department director of the pharmaceutical company that we worked at, asked if I wanted to run a project for him. I was an experienced maintenance electrician at the time, 36 years old, and looking for something more then routine maintenance. In those days of my work I had evolved from general plant wide electrical maintenance into the “controls man” of the department with new equipment coming to our company every month with bigger and bigger control panels containing rows and rows of relays and interconnecting wires.
    Between May of 1965 and August of 1966 I had made the jump from Aircraft mechanic, through powerhouse helper, to electrician helper. That period of my life was a bit hectic and a story of it’s own. However, having a father as an electrical contractor afforded me an opportunity to “learn the trade” during my teen year summers and that helped me when I attended an electrical course at my work.  In those first months as electrician I was junior man in the shop while the most complicated electrical scheme was a conveyor interlock circuit; start this before allowing to start the next conveyor. The “old” guys didn’t want to repair the new equipment that was coming in monthly so it fell to me to do the job. I loved it. Logic was my “thing”.
    That’s a bit of background to put this all into context. When Jim Stott asked me to take on his project we were swimming in a sea of relay controlled machines that were mostly maintained by my partner, Jack Trout, and I. Jack was a little older then I and had more time in as an electrician but he wasn’t too keen on control work. We did OK keeping all the new machinery, loaded with control relays and timers, running. There was one machine that required more then others in the way of parts and service, the palletizer.
    To say it took more service then the other machines is an understatement. The palletizer took as much attention as all the other machines times two to keep it running. The biggest problem was the Mylar tape reader that hung on the front of the control panel. It went through a single Mylar tape each week along with at least one control relay that had to be replaced. The machine sounded like a constantly operating machine gun. Of course it was doing many things in very fast order taking a constant stream of product boxes, orientating them on a stripper plate, and stacking the layer onto a pallet.
    The palletizer was the target Jim Stott had chosen for me. He called me into his office and pointed to a box of equipment setting on the floor, a lot of equipment. I asked what it was and he said, “This will make your day”. I opened each box and discovered a wooden box with big rectangular buttons on it with lettering that said things like “Examine ON”, “Timer Load”, and other unfamiliar terms.  In another box was a somewhat smaller item that had an exposed UV memory chip (DIP) that I had seen before. I had built a grease pump controller for the Big Ben coal mine shovel which operated close to our home on Baseline Rd. I was experimenting with some Texas Instrument DIP chips at that time because I saw that it would probably be the way of the future.
    Now that I think back of that unit, programmer, controller, and power supply, I consider it as a monster. At the time, Jim told me that he wanted me to replace the Mylar tape reader on the palletizer with the unit there on his office floor. He explained that the controller and power supply was all that would remain on the machine. I took the equipment back to my work bench in the electric shop and started reading the instructions. By noon time I had completed my reading and as the shop electricians started filing in for lunch I received a bunch of comments about, “Your new toy”.
    I defended the collection of “stuff” on my work bench as best I could never realizing it’s full potential at the time. I absolutely knew that it would be able to replace the Mylar strip reader on the palletizer, I knew it would. I even stuck my foot out and said it could replace all the control relays in the palletizer control panel. That was what I read moments before in the instruction manual but had no idea that that was what I would eventually do in the weeks to come.
    So, first things first. I laid out a plan that would install the PLC controller on the outside of the machine control panel there was absolutely no room on the inside. The palletizer was operated 24 hours a day 5 days a week, so the change over to replace the tape reader had only 48 hours from cut out to running in production. The physical replacement of the tape reader only took an hour or so including the installation of the power supply. The programming of the controller took most of the remaining day. The programming was tedious and required no errors.

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  • babajim October 22, 2018

    The procedure required that the memory chip be completely erased before entering the program. If I remember correctly, some elements could be added but nothing could be changed. The program was built and then written to the chip, which all together took about an hour each time. I would then test the system for proper function. It took a couple of times before I got it right, but when I left the machine, after working for about 12 hours, I knew it would be OK for production use.
    When I came to work the next Monday morning there were more people watching that palletizer then I could have imagined. Engineers, company management, and of course my boss. All eyes were on the first boxes coming down the line. The palletizer was standing in it’s position with an empty pallet properly loaded in position. The boxes flew onto the stripper plate in their correct order, the stripper plate moved back, the boxes fell onto the pallet, the pallet moved down the required amount, the stripper plate moved back to receive the next set of boxes in their correct order, and “the band played on” for the rest of the day without a hitch or stumble. The only thing missing was the noise and clatter of the unused relays.
    After the first few minutes many people went back to work because they weren’t really interested in seeing a well working machine run all day, they just wanted to be there when it flopped or crashed. My interest was in seeing a perfectly running machine do it’s thing day in and day out. I still enjoy watching fine operating machines. That was the day I knew that my job as an industrial machine repairman had expanded beyond what I could have ever imagined. It would not be the last day the palletizer would see me for some other changes. When I went back to Jim Stott’s office for our lunch time together, he said something I have always remembered, “Wasn’t that fun?”. We spent the remaining part of the hour laying out logic scenarios on his chalk board.
    That day I started to lay out for him that that one controller could now replace ALL the remaining control relays in the palletizer. He had not expected to replace all the relays and timers and was not sure I could do it because I had used up many of the timers and relays in the Mylar tape reader replacement. I spent a few days drawing up a relay logic diagram that I could use and it didn’t use all the available programmable items. He agreed to let me do the job. I would need to set up a schedule for the three shifts of electricians to remove the unneeded relays and timers, mount the PLC controller on the inside of the electrical control panel, and program the machine.
    All this and test the palletizer had to be accomplished in a similar 48 hour weekend window and be ready for production on Monday morning. I am not an electrical engineer, no I am not, I am an industrial repairman, I fix things. I laid out a work schedule for the electric shop that was not time sensitive, things had to be done in order but could be done by anyone. So, as electricians came up to work on the palletizer they just needed to look on the work schedule and do the next thing in line and when accomplished check it off as done.
    The job went well, I was called Sunday morning and told that all the required electrical work was done and the next thing was to test the machine. I came in to work after church and within a few hours was headed home with the knowledge that Monday morning would be the beginning of new life for the palletizer.
    Monday came and the production line startup was on-schedule. Not as many people showed up this time compared to last time. I guess not many people expected to see a wreck. When we opened up the electrical control panel after the relay replacement we now had no more “relay dust” to clean up each week and the equipment inside looked lost in space. Now the sounds that emanated from the palletizer were from the air cylinders doing their thing and zero sound from relays except when the palletizer was first turned on Monday mornings. What a change that first PLC made in the operation of the palletizer and me as well. My next PLC was an Allen Bradley PLC2, the second and most dear to my heart for a long time.
    By- the-way, as far as the available relays left unused, after I tweaked the palletizer PLC program in the following weeks, it ended up with all of the relays and timers/counters being used. It was devoid of any left over elements. I was even able to put a program segment in that informed the operator that it was time to spray the box separator roller when it started to slip. The operator loved it, and as I always have, I look for that final touch to a program that not only makes it fully functional but elegant in operation as well.

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