Siemens SIMATIC ET 200AL, System Manual

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OPC UA communication
9.1 What you need to know about OPC UA
Communication
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Scalability
OPC UA can be used for devices of different performance classes:
•
Sensors
• Embedded systems
• Controllers
• PC systems
• Smartphones
• Servers running MES or ERP applications.
The performance class of the devices is differentiated by profiles. Different OPC UA profiles
offer the possibility to scale OPC UA for very small and simple devices as well as for very high-
performance devices.
An OPC UA profile describes functions and services that must be supported by the server and
client. In addition, other functionalities/services that are not required by the profile can be
optionally provided.
OPC UA profiles differ from PROFINET profiles; the latter define additional cross-vendor
properties and behavior for installations and systems in the sense of a vendor-neutral
software interface.
Nano Embedded Device 2017 Server Profile
For the smallest devices with severely limited functionality, there is the "Nano Embedded
Device 2017 Server Profile" of the OPC Foundation. This profile is functionally equivalent to
the core server facet and defines the OPC UA TCP binary protocol as the required transport
profile. The profile allows for connections without UA Security and does not allow
subscriptions or method calls. Support for diagnostic objects and variables is optional for this
profile.
Additional profiles build on the "Nano Embedded Device 2017 Server Profile", requiring more
resources and offering more functionality.
Micro Embedded Device 2017 Server Profile
This profile provides limited functionality; it requires at least two parallel connections.
Additionally, it allows subscriptions/data monitoring, but no UA Security and no method calls.
•
S7-1200 Basic Controllers support the "Micro Embedded Device 2017 Server Profile". The
S7-1200 additionally supports UA Security.
Embedded 2017 UA Server Profile
This profile has been developed for devices with more than 50 MB RAM and a more high-
performance processor. It is based on the Micro Embedded Device Server profile. In addition,
it requires UA security and method calls.
In addition, the servers must make their used type model (data types, reference types,
variable types, etc.) available.
•
S7-1500 Advanced Controllers support the "Embedded 2017 UA Server Profile".