ABSTRACT
This chapter reviews the general aims of plant automation and the benefits that accrue from it. It discusses how control and automation evolved from conventional instrumentation to computer-based control, leading to the present day distributed computer control. The chapter provides an insight into the individual techniques and methods that have already been available for solving plant automation problem, and whose appropriate integration has led, in a natural manner, to the concept of modern distributed computer control systems. The idea of possible computer control was born with the work on sampled data control systems, but the digital computers, developed at that time, were not fast and reliable enough to be seriously considered for application in process control. The new value is necessarily to be latched before being transferred both to the controller and the computer, that is at the moment insensitive to its analog input channel. The development of minicomputer technology gave rise to rapid increase of computer-based control systems.
