Simulation Of Industrial Control System Based On OPNET

With the continuous development of IT technology,the integration of the industrial control system and network communication system has become a hotspot of the control network technology.So networked control systems(NCS)was put forward.Network or bus is added to a traditional control system as a communication medium,the performance of the system has been greatly improved.The networked control system has always been the focus of research in universities and scientific research institutes,and the research on the design,simulation and optimization of NCS has never been stopped.modern networked control system introduces a large number of IT technologies to form a new automatic control system integrating control,scheduling,management and operation,making it the main symbol different from the traditional networked control system.Because of the use of the network,the scale of production has gradually expanded,and the regional nature of the project has gradually expanded.For example,water quality monitoring,wind power and high-speed rail network,networked control system based on WAN has become a new research direction in terms of remote maintenance,remote monitoring and remote control.The cost of building a networked networked control system based on a WAN is too expensive,computer simulation is the first choice of research.In this paper,a simulation model for networked control systems based on WAN is proposed and an extensible hardware-in-the-loop simulation platform is implemented.The platform can effectively integrate the numerical simulation systems and the physical systems;flexibly configure the network model;collect the physical systems data in real time.OPNET is used to build WAN models which simulate the user's online behavior and background traffic.An OPC client is embedded into the OPNET simulation environment to compose an OPC hardware-in-the-loop simulation agent node which is a data channel between WAN models and physical systems.An optional controller is used to run the control algorithm.An experiment which involves distributed denial of service(DDoS)attack against the control node in the WAN is carried out on this platform.The simulation results show that the DDoS attack affects the system stability when the traffic reaches a certain flow rate.Under the influence of DDoS on the stability of the system.Then on the server side of the platform on which the source address a white list filtering attack defense mechanism is added.The impact of DDoS attacks on the system is eliminated significantly.In the meantime,the experiment proves the practicability of the simulation platform.