The situation of using industrial ether network in DCS system of Zhujiang Power Plant has been presented

including the structure of main communication network in DCS

and the structure of low level communication network in DPU distributed processing unit

and the situation of using communication network for XDPS400 system being analysed. Directing against the problems existing in the original system

such as the load of network being comparatively high

the communication rate of I/O bus being comparatively low

an upgrading retrofit has been carried out as follows:(1) the main networks A and B are upgraded from bus ether network to opticfiber virtual loop network and the exchanger of industrial ether network being replaced; (2) the DPU low level communication network is upgraded from hitBUS to ether network; (3) the nonreal time control network (C network) is upgraded from bus structure to star structure

and being connected by using low cost DLINK 24 channel exchanger. After upgrading

the real time behavior

safety

reliability

maintainability of the network all to be greatly enhanced

completely satisfying the requirements of power plant control.