PLCs have been around forever (in technology years). Their proven reliability in harsh environments and design to handle many inputs and outputs has made them the foundation of many automated systems.
Today there are a lot of alternatives to the traditional PLC. In some applications we use a computer based control engine. In other applications it is reassuring to know that the PLC is one less thing you'll have to worry about.
PLCs can be combined with most other technologies to provide a sophisticated control and monitoring system. Most of our information regarding PLCs can be found in our PLC Tutorial.
PLC Tutorial This tutorial contains several pages on what PLCs are good at, what they are not good at, what the major components are, and our views on how they should be used.
Major Automation Companies All of these companies have PLCs.
Control Engines Alternatives to traditional PLCs
Industrial Networking PLCs have to be heard