Abstract: Since its inception, the open PROFIBUS technology has been under continuous development, aiming to provide logical expansion for its application areas. From the perspective of automation architecture, for a long time this development process was only about the horizontal expansion of communication mechanisms and application rules. However, in recent years, the vertical expansion of PROFIBUS technology, while fully retaining its existing openness, has become a decisive trend, integrating industrial automation with higher-level IT technologies in the office of enterprises/global networked companies. According to customer requirements, PROFInet provides an open and consistent PROFIBUS vertical integration solution, fully meeting the requirements for protecting customer investment, namely: integrating existing communication and automation architectures. Keywords: PROFIBUS; PROFInet; automation architecture; industrial automation; IT technology 1. Introduction The PROFIBUS International Organization, representing more than 1200 member companies worldwide, launched the PROFINET automation solution based on real-time industrial Ethernet. This technology provides current users with a complete, high-performance, scalable solution for upgrading to an industrial Ethernet platform. PROFINET is a significant and strategic technological innovation that provides Ethernet migration services not only for PROFIBUS but also for other fieldbus network systems. PROFIBUS is an international, open, and device-independent fieldbus standard widely applicable to manufacturing automation, process industry automation, and automation in other fields such as building automation, transportation, and power automation. PROFIBUS consists of three compatible parts: PROFIBUS-DP, PROFIBUS-PA, and PROFIBUS-FMS. PROFIBUS specifies the technical characteristics and functions of a serial fieldbus system that allows distributed automation devices in the field to be interconnected into a network at low and medium performance levels (sensor/actuator and unit levels, respectively). The PROFIBUS bus access method conforms to the European standard EN 50 170, employing a token passing principle with master/slave polling. In process and manufacturing applications, PROFIBUS fieldbus technology saves significant amounts of cabling, cable trays, and connectors, reduces system design, commissioning, and maintenance time, and facilitates communication between field control devices and between devices and the control management layer, creating conditions for control information to enter public data networks. Its location-independent control, high-speed communication, flexible topology, true interoperability, and openness give it significant advantages and broad development prospects. Therefore, PROFINET encompasses all the important aspects characterized by open, consistent, and decentralized automation. These systems offer many important advantages due to the significant reduction in time and overhead spent on configuring and operating machines and equipment. (1) New Prospects for Industrial Automation Improving factory productivity remains a constant goal. Factories want to invest in enabling production to respond quickly to the latest market demands and shorten time to market for new products. This requires strategic decision-making based on a continuous flow of information across the factory: from the front line of production to the factory control layer and down to management. Therefore, information technology, especially information technology based on production automation, will become a major force driving production efficiency, reducing production costs, and promoting enterprise innovation. (2) Achieving Innovative Industrial Ethernet Standards with PROFINET PROFINET, an open, cross-vendor standard based on industrial Ethernet, enables direct and transparent access from the company management level down to the field level. PROFINET is based on existing mature IT standards and provides full support for TCP/IP. Users can easily extend and integrate with existing systems. 2. Objectives In 1999, with the convergence of IT across different sectors, the PROFIBUS International Organization seized this opportunity and began seeking solutions for open PROFIBUS technology within enterprises, applicable to production and management levels. One objective was to find a vertically scalable architecture that, on the one hand, allowed for the comprehensive and sound preservation of existing open capabilities; on the other hand, it enabled seamless integration between system components based on the widely available traditional PROFIBUS technology. For PROFInet, its openness was further extended due to its open interfaces with various fieldbuses. This allowed for easy integration of solutions from all bus systems into the PROFInet system. A further objective was to ensure broad consistency, enabling users at all levels to communicate and collaborate using the same mechanisms. This included both lateral communication between automation devices (automation integration) and vertical communication between office, management, and field users (enterprise integration). An object-oriented component model provided the foundation for this approach. [align=center]Figure 1: Industrial Communication with PROFInet[/align] The PROFInet solution places particular emphasis on unified, plant-wide engineering based on a unified data model and recognizes the necessity of establishing applications through graphical, text-based, or script-based object interconnection, as this makes processing tools both intuitive and easy. PROFInet—Open, Consistent Connectivity for Offices and Automation The PROFInet solution covers all operational phases of distributed automation systems. It includes the following key aspects: • Open object model (structural model) for highly distributed automation systems • Open, object-oriented runtime communication scheme based on Ethernet (communication relationships between functional units) • Manufacturer-independent engineering design scheme (application development) Based on this scheme, the PROFIBUS International Organization has developed an automation solution that not only allows all bus vendors to interconnect but also enables direct communication with higher-level enterprise IT. 3. Object Model The PROFInet structural scheme is based on Microsoft-defined COM objects (Component Object Model). This allows application development based on finished components. Components are built as objects, and objects communicate with each other through defined interfaces. A COM interface has a specified number of functions, described in an Interface Definition Language (IDL). A component supports a specific interface (an interface carefully defined using certain methods), which is essentially what is commonly referred to as: implementing an interface with a component (this involves the implementation of the defined interface and its semantics (services)). From the user's perspective, a COM component is simply a number of interfaces. By invoking the functions of an interface, the client can access the services of that type of component. PROFInet distinguishes between objects in the engineering system (ES objects) and objects in the runtime system (RT objects). During engineering design, ES objects represent RT objects. The examples, interconnections, and parameterization of ES objects form a model of an automation solution for a specific plant. Using the evaluation of the engineering model, downloads can trigger the generation of runtime software. The PROFInet scheme follows the fundamental idea that each RT object in the runtime system corresponds precisely to an ES object in the engineering system, facilitating the mapping of the engineering domain to the runtime domain and vice versa. In this way, relationships between ES objects can be easily mapped to relationships between corresponding RT objects. These statements apply to typical engineering of equipment (ES devices) and software (ES automation). In this scheme, ES objects and RT objects are considered two distinct objects. Firstly, configuration occurs during the runtime period when the operational domain (device) is not yet available; secondly, the objects have different functions, as only RT objects can generate actual automation functions. 4. Runtime Communication Runtime communication is conducted through the COM object interface in the form of an object protocol based on a draft object model. The runtime model represents the actual objects available on a device, whose interfaces, methods, and relationships between objects can be accessed externally via OLE automation. It makes no assumptions about interface implementation, thus maintaining maximum flexibility during implementation (as long as the object image remains on the device's communication lines). The runtime concept is based on traditional Ethernet communication mechanisms such as TCP/IP or UDP. This basic mechanism has later been enhanced with RPC and DCOM mechanisms. DCOM can be seen as an extension of COM technology for RPC-based distributed applications. Alternatively, optimized real-time communication mechanisms can now be used for applications with demanding real-time requirements. During runtime, PROFInet components are mapped as DCOM objects, thus ensuring communication between DCOM objects through the object protocol mechanism. Automation objects, or COM objects, appear as PDUs on the communication bus in the form of DCOM protocol definitions. Through the "DCOM cabling protocol," DCOM defines the object's identifier and methods with relevant interfaces and parameters. This allows for the transmission of standardized DCOM packets on the communication bus, which is defined by the interface. These packets are generated at the client side and evaluated and interpreted by the server. A key feature is that no COM object is required within the server. It fulfills the need to generate "illusions of an object" on the bus. Connected Object Activity Control (ACCO) ensures the establishment of communication relationships and data exchange between configured interconnected devices. The transmission itself is event-controlled. ACCO also handles post-failure recovery. This includes: transmission of quality codes and timestamps, monitoring of connected partners, re-establishment of connections after loss, and testing/diagnostic of interconnectivity. 5. Engineering Solution The user-friendly PROFInet engineering solution is a unique and specific solution, an automation solution not achievable through any other fieldbus or emerging Ethernet solution. With PROFInet, automation objects running on PROFInet devices can communicate with each other during operation. Boundary conditions and communication connections were defined during the engineering design process. To this end, an engineering object model has been defined, which establishes the technical framework for using Engineering System Automation Objects (ESAutos). This unified basic model allows for the integration of engineering system automation objects and engineering development tools from different manufacturers. This engineering object model not only uses configuration development tools for components from different manufacturers but also recognizes manufacturer specifications or application-oriented functional extensions using facet methods. A clear separation between the equipment itself relying on manufacturer programming (component generation) and the interconnections within the installed equipment scope using higher-level engineering tools (application configuration) enables the integration of products from different manufacturers within a single factory. 6. Specific Applications Currently, the application of PROFInet in China is still in its early stages, with only a few companies and organizations adopting PROFInet architecture layouts. We are currently attempting to integrate a PROFInet solution into a nuclear power equipment factory in China. The top layer of the system is the Internet, through which the factory's internal network can communicate with external networks. The middle layer is PROFInet, which includes the factory's management control units or software for workshop equipment. The bottom layer is the PROFIBUS-based fieldbus unit, specifically including various sections, controllers, actuators, field devices (such as sensors and instruments), and automated equipment (such as lathes and milling machines) on the automated production line. We can monitor the operation of various equipment in the workshop through the interface between PROFInet and the fieldbus, achieving the goal of process-oriented and rational integration of the management and field layers. The specific system scheme is shown in the figure below: [align=center] Figure 2: PROFInet Specific Application Integration Scheme[/align] We have conducted a preliminary analysis and demonstration of this system integration scheme, and theoretically proved that the scheme is indeed feasible. 7. Conclusion The author's innovation: Through the research on the PROFInet Ethernet fieldbus, its application scope has been vertically expanded from a simple communication mechanism to integrated industrial automation. Through specific practical scheme analysis, it is proven that PROFInet is an Ethernet fieldbus combined with PROFIBUS. It can improve the management and monitoring of automated equipment networks from both macro and micro perspectives, standardize industrial processes and production order, and play a significant role in industrial automation systems. [References] [1] Ran Quan, Yang Zhifang. Discussion on the application of Ethernet in industrial control. Microcomputer Information. 2002, (18). [2] Li Li. Application of Ethernet and fieldbus in industrial networks. Microcomputer Information 2001, (17). [3] Xi Bo, Fang Yanjun. Research on network communication technology in industrial Ethernet. Microcomputer Information 2005, (21). [3] Yang Xianhui. 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