Design and implementation of data communication interface for power plant
Zhong Yan-hui, Abb Beijing · Dianli zidonghua shebei · 2010
DCS(Distributed Control System) and SIS(Supervisory Information System) are widely used in power plants to realize the automated management of unit information.The peripheral subsystem of power plant can adopt Modbus,OPC,API to access DCS data.MSComm of ActiveX controls can be used to develop the Modbus communication based on RS-232.OPC communication is base on Client / Server structure.OPC server supports two types of communication interface:customized and automatic interfaces.API is used to exchange data with controller.The API of SIS is a group of C functions and the application software accesses SIS by calling API functions.It is also quite common to connect the OPC client with the OPC server of SIS.Plug-in is supplied by some SISs to realize the DDE between Excel and SIS.The features of different communication interfaces are introduced and the key points in programming are mentioned.