Security is a key feature of UA but security requires that the Servers be able to publish their security requirements so Clients can know how to connect. UA makes this possible via the Discovery Services which have been discussed in prior posts. U ...[Read More]

A comment on the v1.1 SDK by Mike Dillamore over at OPC Programmer's Connection prompted me to think about the differences between developing community software and developing commercial software. When developing commercial software the developm ...[Read More]

After a long hiatus I finally have some time to start blogging again. This time I hope be more frequent in my postings. A lot has happened since my last post including the formal release of V1.0 of the UA SDK and the most recently posted V1.1 Be ...[Read More]

Previous posts discussed how every UA application instance has an X509 certificate assigned to it and how UA Security Policies describe standard security configurations for UA Server endpoints. What was not mentioned was how this information is ...[Read More]

Configuring application security for a typical Web Services application is extremely complex because there are a huge number of configuration options that control things such from the cryptography algorithms used to the order of elements in the ...[Read More]

In the past OPC specifications were silent on security and application developers were expected to use the operating system infrastructure to secure their applications. What this meant in practice is most OPC systems were insecure by default. The ...[Read More]

UA is a specification that is based on the web service model. This means that all of the services defined in the UA specification are described by a WSDL which can be used by any application that understands WSDLs. The UA specification also defi ...[Read More]

After 5 years of development UA is about to be released. The 1.01 version for the UA core specifications (Parts 1 through 8)  should be posted in a couple weeks. The IEC 62541 Working Group has just approved the committee draft which means UA is ...[Read More]