ABSTRACT
One of the fundamental tenets of the integration of industrial automated enterprises is unrestricted and timely flow of data between applications at different levels of the enterprise hierarchy — for example, between shop-floor and enterprise level — as well as between different applications at the same level. This data exchange takes place among various IT infrastructure elements functionality and performance requirements of which are determined by their level in the hierarchy and the application they support. They may be controllers and operator workstations at the manufacturing/process level; workstations supporting the Manufacturing Execution System application; gateway servers in between control networks and the plant network; workplaces at the enterprise or business level supporting, for example, the Manufacturing Resource Planning application; etc. The primary conduit of data exchange in modern automated systems is a specialized communication infrastructure that takes on a hierarchical arrangement, with individual networks reflecting to a large extent the needs of applications at different levels — in terms of functionality and performance (data size, throughput, delay, availability, etc.). The life cycle of a plant spans typically many decades of operation, resulting in heterogeneity of the manufacturing/process equipment installed, supporting IT infrastructure, and applications to operate and maintain the plant. This translates into a diversity of field devices and supporting industrial networks, software platforms supporting applications, and languages used to develop those applications. Integration of the communication infrastructure of a plant and applications (largely implemented in software) is needed to achieve the required seamless and timely data flow throughout the entire enterprise. This is the focus of this chapter and a large portion of the book.
