History of the PLC
Programmable logic controllers (PLCs) first hit the scene in the late 1960s. The primary reason for designing such a device was eliminating the large cost involved in replacing the complicated relay based machine control systems for major U.S. car manufacturers.
Some companies proposed schemes based on the Digital Equipment Corp. DEC PDP-8, the widely-used mini-computer at the time. Dick Morley’s company Bedford Associates in Massachusetts proposed something called a Modular Digital Controller (MODICON). The MODICON 084 brought the world’s first PLC into commercial production.
Since then, a slow steady growth has allowed the manufacturing and process control industries to take advantage of PLC applications-oriented software—programmable language that looks and feels like relay-ladder-logic where any maintenance technician.
Morley is generally credited with the “invention” of the PLC. However, there were many others involved in the birth of this landmark development, including the late Odo Struger (from Allen-Bradley, now Rockwell).
Morley said details of the PLC came about on 1 January 1968. Some 35 years later, it is arguably the most widely used product in the industrial automation business, with a worldwide market of several billions of dollars per year. PLC products are available from hundreds of different sources, in many different form-factors (including embedded controllers), and with prices ranging from tens of thousands of dollars (for triple redundant, failure-proof systems) to commodity products at less than a hundred bucks.
Take a look at this History of the PLC, as told to Howard Hendricks by Dick Morley himself. In true Morley fashion, he calls these “fables,” which may or may not have a basis of truth; but he insists, they are the best that his memory can do after all this time.
Read, learn, and enjoy.
Related links:
· PLC History:
http://www.plcs.net/chapters/history2.htm
Programmable logic controllers (PLCs) first hit the scene in the late 1960s. The primary reason for designing such a device was eliminating the large cost involved in replacing the complicated relay based machine control systems for major U.S. car manufacturers.
Some companies proposed schemes based on the Digital Equipment Corp. DEC PDP-8, the widely-used mini-computer at the time. Dick Morley’s company Bedford Associates in Massachusetts proposed something called a Modular Digital Controller (MODICON). The MODICON 084 brought the world’s first PLC into commercial production.
Since then, a slow steady growth has allowed the manufacturing and process control industries to take advantage of PLC applications-oriented software—programmable language that looks and feels like relay-ladder-logic where any maintenance technician.
Morley is generally credited with the “invention” of the PLC. However, there were many others involved in the birth of this landmark development, including the late Odo Struger (from Allen-Bradley, now Rockwell).
Morley said details of the PLC came about on 1 January 1968. Some 35 years later, it is arguably the most widely used product in the industrial automation business, with a worldwide market of several billions of dollars per year. PLC products are available from hundreds of different sources, in many different form-factors (including embedded controllers), and with prices ranging from tens of thousands of dollars (for triple redundant, failure-proof systems) to commodity products at less than a hundred bucks.
Take a look at this History of the PLC, as told to Howard Hendricks by Dick Morley himself. In true Morley fashion, he calls these “fables,” which may or may not have a basis of truth; but he insists, they are the best that his memory can do after all this time.
Read, learn, and enjoy.
Related links:
· PLC History:
http://www.plcs.net/chapters/history2.htm