About OPC UA
OPC UA (Unified Arcitecture) is the new generation of OPC
- Replaces DCOM communication with SOAP (Web Services) and binary TCP/IP
- Enables OPC in any operating system and language
- Enables OPC in devices (embedded software)
- Enables WAN (Secure Internet/Intranet/Extranet) connections
- Improves Security Management
- Combines all previous protocols to a common data model
- Targeting to become an IEC standard
OPC UA Stack
OPC UA application development is based on a layered architecture. The OPC UA Stack implements the TCP/IP communication protocol defined by the OPC Foundation. There are different stacks for different development languages and environments, including AnsiC Stack, .NET Stack and Java Stack. Prosys is a major contributor to the Java Stack.
The different OPC Foundation stacks are interoperability tested, so you can use your application with other OPC UA applications, independent of the development environment in which they are created.
The OPC UA Stack is provided by the OPC Foundation and it is available to the Corporation members of the OPC Foundation. The stack is also included in the SDK distributions. The license from OPC Foundation enables you to distribute it also with your own applications.
OPC UA SDK
Although the stack makes all OPC UA service calls available, another layer is required on top of it. The services of the OPC UA servers are expected to function in a certain way, and the client applications must also implement certain infrastructure to enable full use of the protocol. These are typically available in OPC UA SDK products.
The following picture depicts the functionalities of the stack and the SDK. In principle, the stack handles the communication protocol, whereas the SDK implements the base services. The services are more important on the server side, but there is certain infrastucture that needs to be taken care of on the client side as well.
