In 19 years, the first PLC was developed by the National Digital Equipment Company, which replaced t

1. In 1969, the American Digital Equipment Company developed the first programmable controller PDP-14, which was successfully tried on the production line of General Motors in the United States, and was applied to electrical control for the first time by programmed means, which is the first generation of programmable controller, called Programmable, which is recognized as the first PLC in the world.

2. The development history of PLC.

In 1968, General Motors of the United States put forward a request to replace the relay control device. In 1969, the American Digital Equipment Company developed the first programmable controller PDP-14, which was successfully tried on the production line of General Motors in the United States, and was applied to electrical control for the first time by programmed means, which is the first generation of programmable controller, called Programmable, which is recognized as the first PLC in the world.

In 1969, the United States developed the world's first PDP-14

In 1971, Japan developed the first DCS-8

In 1973, Germany developed the first PLC

In 1974, China developed the first PLC

Development: In the early 70s of the 20th century, microprocessors appeared. People soon introduced it into the programmable controller, so that the PLC added the functions of calculation, data transmission and processing, and completed the real industrial control device with computer characteristics.

At this time, the PLC was the product of the combination of microcomputer technology and the conventional control concept of relays. After the development of personal computers, in order to facilitate and reflect the functional characteristics of programmable controllers, programmable controllers were named programmable logic controllers (PLCs).

In the mid-to-late 70s of the 20th century, the programmable controller entered the stage of practical development, and computer technology has been fully introduced into the programmable controller, making its function leap. Higher computing speed, ultra-small size, more reliable industrial anti-interference design, analog computing, PID function and high cost performance have established its position in modern industry.

In the early 80s of the 20th century, programmable controllers have been widely used in advanced industrial countries. The number of countries producing programmable controllers in the world is increasing day by day, and the production is increasing day by day. This marks the maturity of programmable controllers.

From the 80s to the mid-90s of the 20th century, it was the period of the fastest development of PLC, and the annual growth rate has been maintained at 30 40%. During this period, PLC has greatly improved its ability to process analogue, digital computing, human-machine interface and network, and PLC has gradually entered the field of process control, replacing the dominant DCS system in the field of process control in some applications.

At the end of the 20th century, the development of programmable controllers was characterized by being more suitable for the needs of modern industry. During this period, mainframe and ultra-small computers were developed, a variety of special functional units were born, and various human-machine interface units and communication units were produced, making it easier to match industrial control equipment using programmable controllers.

In 1969, the U.S. Digital Device Corporation.

DEC developed the first PLC (PDP-14) to replace the traditional relay control system.