Key Issues Research For Developing Virtual DCS Engineer Station Based On Visio

In practical application of DCS, in order to realize design and debugging of control system and training of operation person, the real DCS should be reproduced in computer system of non DCS. In all forms of representation, virtual DCS is used in personnel training and on-line detection diagnosis effectively, economically and widely, meeting the demand of making process industry because of its higher software fidelity, richer application function and higher investment saving.As important part of virtual DCS, virtual DCS engineer station is closely to virtual DPU the core of virtual DCS. Use ActiveX provided by Visio in C# programmatically and COM interface provided by Visio SDK to develop DCS engineer station configuration software. By accessing various types of objects in Visio, control system block diagram can be converted to numerical information what identified by computer.Control system block diagram is converted to directed topology graph by graph theory.Topology information is stored by adjacency directory storage method.Johnson algorithm is used to look for loop information.The source node and destination node are introduced to Johnson algorithm for looking for the forward path information.By comparing the two kind of information the feedback loops are found,then removed.Topological sort of directed acyclic graph is implemented to obtain the right order of function block.By using FTP server and client, XML file in accordance with PLCopen standard is downloaded to distributed system Virtual DPU and realize the communication with the virtual DPU.Taking cascade control system as an example, this paper accomplishes virtual DCS engineer station function including control strategy configuration design, configuration file information conversion, module automatic sorting, configuration results downloading distally.