General Features Of Opc Ua - Siemens SIMATIC ET 200AL System Manual

OPC UA communication
9.1 What you need to know about OPC UA
9.1.3

General features of OPC UA

The key features of OPC UA
● OPC UA does not depend on a specific operating system platform.
OPC UA can, for example, be used with Windows, Linux, Mac OS X, a real-time
operating system or a mobile operating system (such as Android).
● OPC UA is implemented in various different programming languages.
The OPC Foundation has implemented the OPC UA standard in several programming
languages: Stacks for ANSI C, .NET and Java are available.
● The OPC Foundation offers the Java stack and .Net stack as well as example programs
as open source software. See Github (https://github.com/opcfoundation
(https://github.com/opcfoundation)).
● A number of companies offer Software Development Kits (SDK) containing the OPC
Foundation stacks and other functions to facilitate the development of solutions.
Advantages of using SDKs:
– Support from the supplier
– Tested software
– Detailed documentation
– Clear license conditions (important for selling of solutions)
● Scalability
OPC UA can be used in sensors, embedded systems, controllers, PC systems and
smartphones, as well as in servers running MES and ERP applications.
OPC UA and PROFINET can also be used together. The two protocols use the same
network infrastructure.
● Simple client-server principle
An OPC UA server provides information within a network and an OPC UA client retrieves
this information.
● Integrated security mechanisms
OPC UA uses security mechanisms at various levels:
– A secure connection can only be established between an OPC UA server and an OPC
– A server can request the following from the user before allowing access to information:
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UA client if the client and server can register with X.509-v3 certificates and accept
each other's certificates (security at the application level). Various security policies are
possible, including a non-secure connection between server and client (Security
Policy: "No security").
- A certificate (cannot be configured in STEP 7)
- User name and password
- No user authorization
Function Manual, 12/2017, A5E03735815-AF
Communication