Real-time Data Transfer over the Internet

Abstract

Efficient real-time data exchange over the Internet plays a crucial role in the successful application of Internet-based control. In this chapter, a data transfer mechanism over the Internet is introduced for real-time web-based applications, particularly for Internet-based control systems. The mechanism incorporates the eXtensible Markup Language (XML) and Hierarchical Data Format (HDF) to provide a flexible and efficient data format. Heterogeneous transfer data are classified into light and heavy data, which are stored using XML and HDF, respectively; the HDF data format is then mapped to Java Document Object Model (JDOM) objects in XML, in the Java environment. These JDOM data objects are sent across computer networks with the support of the Java Remote Method Invocation (RMI) data transfer infrastructure. Clients defined data priority levels are implemented in RMI, which guides a server to transfer data objects at different priorities. A remote monitoring system for an industrial reactor process simulator is used as a case study to illustrate the proposed data transfer mechanism.