Abstract
As the integrated product of computer technology, communication technology, instrument technology, and control technology, Fieldbus is one of the focuses of the current technical development in automatic field, Fieldbus is whole scattered, intelligent, bi-directional, interconnected, multivariable and multipoint communication network which connects intelligent working equipment with automatic system. PROFIBUS, as one of the international specifications of fieldbus, has been used extensively in automatization of processing, automatization of machining and automatization of building.