1. AM. Pan, COM Principles and applications, Beijing: TSingHua Unversity Press, 1999.
2. OPC Foundation, OPC Data Access Custom Interface Standard Version 3.00, http://www.opcfoundation.org/DownloadFile.aspx?CM=3&RI=67&CN=KEY&CI=283&CU=12, March 2003.
3. OPC Foundation, OPC XML-DA Specification Version 1.01, http://www.opcfoundation.org/DownloadFile.aspx?CM=3&RI=231&CN=KEY&CI=283&CU=20, December 2004.
4. A. Shonnard, Understanding SOAP, http://msdn.microsoft.com/en-us/library/ms995800.asp x, March 2003.
5. V. Tan, D. Yoo, M. Yi, “Design and Implementation of Web Service by Using OPC XML-DA and OPC Complex Data for Automation and Control Systems,” Sixth IEEE International Conference on Computer and Information Technology (CIT’06),, pp.263, 2006.