Probably the best way to introduce a PLC to someone is to show them something it can do. This particular example is only one of millions of possible applications for the programmable logic controller which is basically a box that can be programmed to carry out particular functions for a machine/process automatically. It can also be programmed to monitor set points or events to either adjust to the condition (the logic must be programmed for this) or to set of some form of alarm. The PLC belongs to the world of automation but it is most definitely a Smart idea and PLC manufacturers round the world are continually developing more advanced programmable logic control for industries and individuals and even for advanced robots too. The following presentation is a brief insight into PLC machine control in a conveyor system with a shuttle press. Notice the black box (PLC) on the top right hand corner is controlling the process.
The supply of PLC units, programming and consulting with industry is a business in it's own right. Engineers and Technicians have been fabricating PLC control panels, relays and monitoring/control systems for many decades although most of the general public may not be fully aware of their presence since this kind of work will normally be carried out by contractors who often install them in control panels which are locked. The following presentation is an example of an active PLC specialist company which can give us a better idea of what a PLC installation looks like in an industrial setting.