Log In
Home
02/14/2018
Offline
I am new in the world of Opc UA and I apologize in advance if I will ask questions that many will take for granted, or worse questions that for many seem ill-posed.
I was studying the OPC UA communication stack and I was struck by the fact that on both the client and server side there is an API layer that is not standardized.
I know that the OPC UA standard standardizes the client and server communication stack and that everyone can develop their own communication stack with their own APIs. So my question is: how can you talk about standards if the communication stack then has non-standardized APIs?
And if I only make a client with my API, how can I then communicate with a server without knowing the server-side APIs? In this case, the server-side and client-side APIs can be developed by two different organizations?
Thanks in advance
05/30/2017
Offline
OPC UA defines the wire protocol in the same way HTTP defines the wire protocol that allow browsers developed by different vendors to talk to web servers developed by different vendors.
OPC UA also defines an abstract programming model that can be implemented in different programming languages. This allows vendors developing APIs to leverage the common model while adding features that make the API more usable for the target users.
02/14/2018
Offline
Thanks Randy
you have been clear, but I miss something, if I wanted to develop a client based on OPC UA and use it in an existing OPC UA client-server system that uses certain APIs on the server side, I need to know and use the same server-side APIs in my client?
05/30/2017
Offline
What are you calling the APIs?
If you develop in .NET (for example) you will need a stack or toolkit that will provide C# APIs.
However, this stack/toolkit are layers on top of the abstract services (a.k.a. API) defined in Part 4 which all OPC UA applications support.
1 Guest(s)
Usage Policy