Designed for energy applicationswww.cechina.cn, the Alstom Control systemwww.cechina.cn, Alspa ControPlant, requires the highest levels for reliability and availability for industrial applications. Alstom, a provider of energy management控制工程网版权所有, power generation, and rail transport systems, uses Alspa ControPlant as its distributed control system (DCS). The incorporation of Modbus and Ethernet Powerlink into the DCS makes the network a central part of the control system.
  

;      Modbus TCP and Ethernet Powerlink function as the fieldbus for the Alspa ControPlant control system. This decision by Alstom required the integration of Powerlink technology characteristics into the control system. The most important of these characteristics is redundancy, which Alstom implemented as a system standard. The redundancy and determinism of Powerlink provides the necessary level of availability for open and closed loop control of the power plant processes.

        Alstom controller topology is run on a Fast Ethernet switched network.

        The site networkCONTROL ENGINEERING China版权所有, mainly located in the control room, has few industrial constraints控制工程网版权所有, and is generally based on a standard Fast Ethernet switched network. A fault tolerant ring topology ensures high availability. Determinism is not needed, as standard Ethernet is used with IP protocol (TCP/IP and UDP/IP). The unit network has a speed of 100 Mbits/s or 1 Gbits/s and is made of fiber or copper.
        Field networks and connected equipment are located at the field level and have the highest constraints. High-speed Ethernet meets the needs of new applications for the power market through increased network performance. To achieve this level of performance, Alstom selected two technologies, one without deterministic constraints and one with high real-time determinism require