Research And Development Of Standardized Communication Interface Of Virtual DCS Based On OPC Server

For the benefit of DCS operator, virtual DCS provides a simulation environment for design, commissioning and dangerous exercises, detection and diagnosis of Distributed Control System. Virtual DCS reproduces DCS which was used in Industrial Automtion Technology on computer system. The virtual DCS developed here was constituted by virtual DPU (Distributed Process Unit), simulation HMI (Human Machine Interface). However, the standardized communication of virtual DCS on open computer system, is the key issue of building a virtual DCS system.OPC is a standardized software interface specification for communication between Industrial Automtion Systems, which was developed by OPC Foundation. Because of its high efficiency and openness, OPC has been widely used in Industrial Automtion Systems for standardized communications between differential data sources. For the achievement of a seamless connection between virtual DPU and HMI, OPC used in virtual DCS initiates a groundbreaking method to realize the standardized communication of virtual DCS.With the background of virtual DCS, a standardized communication scheme based on OPC technology has been taken to realize the OPC standardized communication in virtual DCS. Based on OPC Data Access interface specification(Version3.0), an OPC server was developed on Visual Stdio2010platform with C++language. An storage area for virtual DPU data was built in the OPC server; to hold the data from virtual DPU, An access to virtual DPU was build in OPC server by using the inter-process communication of memory-mapped files; A method to update the virtual DPU data storage area was realized by using messaging mechanism; from which the virtual DPU internal data was embedding in OPC server. From the OPC standardized interface developed in OPC Server, OPC client can get an access to the data from virtual DPU. The HMI of virtual DCS was developed in configuration software, which provides an OPC Client. With the connection test of OPC Client(configuration software) and the OPC server, the communication of virtual DCS system was built, the HMI get an access to the virtual DPU with seamless connectivity, and the information share of the Virtual was realized.OPC technology used in Virtual DCS has been proved to make a good performance, which is also a good example for the OPC standardized communication between Industrial Automtion Systems.