This part of GB/T 21099 specifies the Electronic Device Description Language (EDDL) technology, which allows the use of tools in the engineering life cycle to complete the integration of actual product details. This part specifies EDDL as a common language for describing the characteristics of automation system components. EDDL is able to describe: • Device parameters and their dependencies. · Device functions, such as simulation mode, calibration. • Graphic representation, eg menus. • Interaction with control devices. · Graphical representation: - enhanced user interface; - drawing system. · Persistent data storage.