Brief
Industry the world over constantly strives to improve its production output without increasing its manufacturing costs. The greatest leap in industry was during the 18th century when machine power replaced manually operated machinery. But it was not until the 1970's that the next great leap occured, during the sixties semiconductors started to make themselves known, out went the valve and in came the transitor, which was only a tenth of the size of the valve and required minimal power to operate.
During the late sixties microprocessors came into being and this created a giant leap in how industry would operate. Up until then machinery was controlled by control panels that consisted mainly of relays, the wiring need was immense as was the panel size. Having to make alterations to the manufactring process meant a lengthy downtime as the panels were re-wired or added to. So it was inevitable that the technological advances in microprocessor development would change this for ever.
In the late 1960’s a group of engineers in America came together and looked at how the micropocessor could be used to revolutionize industrial control, one of the problems they faced was that programming was essentially the role of electronic engineers who understood both high and low level languages - Cobol - C - Basic and Assembly. Industry mainly employed Electrical engineers who understood electrical wiring diagrams and relay control. So it was decided to use the power and speed of the microprocessor to provide both manufacturing process control/monitoring along with interpruting a program that could be written similar to an electrical wiring diagram - it was called Ladder programming, the the PLC (Programmable Logic Controllers) was born. Once electrical engineers learnt how to use the PLC, it became easy for them to modify and write programs to operate production processes and even more importantly to use the PLC to diagnose faults and so reduce downtime.
The electronic industry is divided into two main sectors, microprocessor and power, now that the microprocessor had found its place in industry it was up to power electronics to make its mark, this occured with the introduction of Triacs and Thyristors that were now capable of conducting 100’s of amperes, this meant that the relay and contactor world was about to take a large reduction in sales, these power components were unaffected by the problems that relays suffered, no arcing was produced as did in relay contacts when its contacts close, no mechanical wear and tear, no need for slow switching operation.
And so the new industrial revolution was born, power electronics joined with microprocessor technology and created Servo control that allowed motors to be more accurately and reliably controlled, Temperature control was increased to within a few tenths of a degree, Sensor technology replaced the need to have human visual inspection, and so on. With all these new advances production speed increased ten fold.
The demand for further increased productivity seems to be a never ending quest, managers in the 1980’s and 1990’s were finding it difficult to increase productivity without the right information that would allow them to make correct decisions at the right time. So SCADA (Supervisory Control and Data acquisition) was born, this allowed the shopfloor technology to be monitored and controlled in real time from a central location, production data could then linked into the company servers and databases that could be introduced into analysis tools that would allow managers to graphically see how the company was performing, this became today's MES (Manufacturing Execution System).......
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