Providing Methods On The Opc Ua Server; Server Methods - Siemens SIMATIC ET 200AL System Manual

OPC UA communication
9.3 Using the S7-1500 as an OPC UA server
The required license type is displayed under "Properties > General > Runtime licenses >
OPC-UA > Type of required license":
To confirm purchase of the required license, follow these steps:
1. Click "Runtime licenses > OPC UA" in the properties of the CPU.
2. Select the required license from the "Type of purchased license" drop-down list.
9.3.3

Providing methods on the OPC UA server

9.3.3.1

Server methods

Providing user program for server methods
On the OPC UA server of an S7-1500 CPU (as of firmware V2.5), you have the option of
providing methods via your user program. These methods can be used by OPC UA clients,
for example to start a manufacturing job using the method call of the S7-1500 CPU.
OPC UA methods, an implementation of "Remote Procedure Calls", provide an efficient
mechanism for interactions between different communication nodes. The mechanism
provides both job confirmation and feedback values so you no longer have to program
handshaking mechanisms.
Using OPC UA methods, you can transfer data consistently without trigger bits/handshaking,
for example, or trigger specific actions on the controller.
How does an OPC UA method work?
An OPC UA method in principle operates like a know-how protected function block that is
called by an external OPC UA client during runtime.
The OPC UA client only "sees" the defined inputs and outputs. The content of the function
block, the method or algorithm, remains hidden to the external OPC UA client. The OPC UA
client receives feedback on successful execution and values returned by the function block
(method), or an error message if execution has not been successful.
As the programmer, you have full control over and responsibility for the program context in
which the OPC UA method runs.
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Function Manual, 12/2017, A5E03735815-AF
Communication