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Fieldbus industrial control network has become an important technology in the new generation of industrial control systems, it is a concrete realization of the underlying computer network technology in industrial control, computer network technology as the representatives of the information technology, with the combination of industrial control systems greatly improved the level of the control system. With the rapid development of computer technology, communication technology and control technology, industrial control systems integrated automation system architecture direction toward the on-site network. Since computer networks there are significant limitations in the actual network environment, research field simulation methods were studied. Computer network simulation for the new development of computer networks and industrial control network provides a convenient and efficient verification and analysis methods. NS2 is developed on Unix systems, including Tcl, Tk, Otcl, and TclCL four package is a general purpose, visualization, scalability, object-oriented network simulation software. NS2 itself has a virtual clock, all simulations are driven by a discrete event, use the C and Otcl as the development language. NS2 can be used to simulate a variety of different IP networks, and support for multiple protocols, Red and so on several router queue management mechanism, and dynamic routing, static routing, multicast routing, routing algorithm, in addition to support multicast protocols SRM and some MAC layer protocol, and provides a variety of traffic simulation, respectively, according to the exponential distribution, Pareto distribution, trace files, or indeed different rate traffic. The paper using the NS2 network simulation software to simulate and study the enterprise information network the Hl-based bus. Studies are as follows: First, the development of industrial control network described the significance of industrial control network and the integration of the computer network and computer network simulation. NS2 network simulation software structure, characteristics, methods are introduced, NS2 tools described. NS2-based the Hl bus network modeling and simulation, and the network system optimization. , Collation and analysis of data collected by the simulation, the TCP / IP congestion control, flow control, and self-similarity analysis. In this paper, the corresponding network environment modeling, and the nature of the different nodes and links in the modeling process were different settings. And carried out a detailed analysis of the collected data and draw self-similar flow and non-self-similar flow aggregation occurs is still self-similar flow this conclusion.
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