Sometimes described as “the workhorse of industrial automation”, a programmable logic controller, or PLC, is a computing device that is specially designed for use in an industrial operation.
A PLC can take many shapes and sizes, but in most instances it does not look like a conventional desktop computer like the ones you find in offices or in homes – a PLC has no display screen, no hard drive, and no keyboard.
PLCs started out in the automotive manufacturing trade, although they can now be found in almost all sectors, where they tend to replace relays.
Relays are devices that essentially turn machines on and off, and are said to be time-consuming and complex to use compared to PLCs. Relays also require more operational downtime when they need to be reconfigured. PLCs are estimated by one research company to reduce downtime from 20 percent to about 4 percent. [Read more…] about Top 20 programmable logic controller manufacturers