PLC

A brief introduction to PLC

Ever ask yourself: What is a PLC? And what are its benefits?

The term PLC is an abbreviation of Programmable Logic Control. The first programmable controller was first manufactured at General Motors in 1968. The device was initially only replacing the traditional reel, but it was not able to meet the requirements of the manufacturer, but it was the beginning of a new generation in the manufacture of programmable devices, which developed later, and spread widely in all fields of industry.

As a result of technological progress in the microprocessor industry, programmable devices have become more flexible and intelligent. It has become easier for technicians and engineers who do not have great knowledge of computer science and digital electronics to deal with such devices. They have even become able to perform arithmetic and logical operations and can be controlled using different languages ?? which were used before.

In the period between 1975 and 1979, there was significant progress in the manufacture of programmable devices, and this development also included an increase in the ability of the microprocessor to speed up program execution.

Also, it became easy to store any program in an external memory unit, and change the previously stored data during operation, so the programming unit can change the values ??of programmed time-timers, programmed counters, shifts of variable values and comparison keys, without stopping industrial production lines as was previously.

As a result of the development of communication sciences, it became possible to use logic controllers to work together in a local network to control the factory, as if they were one device. It was possible to make adequate reports on production, maintenance and malfunctions by external units connected to the PLC device, such as printers or touch screens. These reports serve factory departments to improve the production rate or help in detecting malfunctions, such as malfunctions that occurred in a certain time period.

Due to the high demand in the industrial field for PLC intelligent programming units, manufacturers competed to develop the device.

The results of the huge developments in the technology of manufacturing logic controllers were the following:

1- The cost of the device has become so low that it can be used instead of tens of relays.

2- It has become possible to use small size control devices in ANALOG.

3- Various sizes of programmable logical units have appeared, some of which have only about ten entrances and exits, and some of them have several thousand entrances and exits.

4- Using languages ??that are easier for those who do not have computer knowledge to use.

5- The possibility of identifying faults and modifying the internal data during the operation of the industrial process.

6- Using cables to transfer information to and from the programming unit at a speed of up to 187.5 Kbps.

7- The usage of the PLC units in the industrial field has increased.