The basic process unit

Abstract

A process control system comprises a process involved in a controlled system and a process controller. Functions of the entire process control system are described in this chapter. The basic process unit which integrates all essential process and process control functions is identified as the basic building block of the process control system, both for its vertical and horizontal integration. The most critical parameter of the functioning of the basic process unit is its data processing ability. Therefore the different functions of the basic process unit controller are considered separately. The necessary data processing functions of the controller are established and analysed as based on available data processing time. The timing relations and informational features of process input/output devices are also given because they limit the functional and informational characteristics of the basic process unit and therefore the entire process control system.