Profile

Motivation

OPC UA combines the functionality of OPC DA, OPC HDA, and OPC A&E, and introduces additional features like historical Events and Methods. Not every OPC UA application will support all the functionality of OPC UA. For example, a server running on an embedded device may not provide any historical information or may even not be able to support subscriptions. Some servers are able to track changes in their Address Space, others not. The same is true for clients. For example, some clients will only deal with current data, others will only subscribe to Events. To handle OPC UA applications with different functionalities, OPC UA introduces Profiles.

Profiles define the functionality of an OPC UA application. A Profile can be used by vendors for marketing (“my product supports these features”) and as decision support for customers (“I need a product supporting these features”). To verify that an application really supports a Profile there are test cases defined for the features of a Profile. Independent testing authorities will test the applications and create signed Software Certificates for the application. Those Certificates contain information about the supported Profiles.

Profiles are not only used as human-readable announcement, but information about the supported Profiles is also exchanged between OPC UA applications. This allows applications to reject connections when their counterpart does not support required Profiles. It also illustrates the features supported by an application and allows other applications to only use those features and not try to use features that are not supported.

In the following section we will introduce the different building-blocks for Profiles and explain the different kinds of Profiles. Afterwards we will look at client- and server-related Profiles as well as transport- and security-related Profiles. Finally we will describe the certification process of how you can get signed Software Certificates.