Apart from theoretically examining how the SOAP protocol can be used to efficiently represent and transport fieldbus data, the thesis considers existing standards in this domain, in particular, the OPC XML Data Access (XML-DA) specification. Furthermore an OPC XML-DA server for an existing Internet/fieldbus gateway is developed and analyzed for interoperability and performance.
The thesis shows that SOAP Web Services provide a decent solution to the needs of Internet/fieldbus interfaces, with the advantages of interoperability, legibility of the protocol to humans and high suitability for deployment on the Internet.
However, certain disadvantages such as complexity of the specification, considerable bandwidth and CPU requirements and a significant memory footprint seem to limit the broad deployment of this technology in industrial automation.