How the control challenge is solved
The control challenge is in effect to reduce the need for human operators to be present at a machine or process continuously. There are many ingenious methods invented for this purpose. All these methods make use of intelligent processors, which are smaller, faster, and cheaper than at any other point in the past. With each method, the main objective is for attendance by humans to a problem in production to be made unnecessary, or for attendance to be at a convenient time rather than being immediately necessary. This is what we mean by reducing dramatic intervention.
Stored program controllers
One significant development in controllers is the invention of stored program controllers (PLCs). A PLC has built-in program memory. The innovation comes in the form of a program that can be resident in this memory. The PLC performs tasks as per the instructions in this program. Since memory chips have become smaller and denser, it is now possible to...
