Siemens SIMATIC ET 200AL - OPC UA Server Instructions for the Implementation of Methods; Opc_Ua_Servermethodpre

OPC UA communication
9.3 Using the S7-1500 as an OPC UA server
Communication
184 Function Manual, 12/2017, A5E03735815-AF
9.3.4
OPC UA server instructions for the implementation of methods
9.3.4.1
OPC_UA_ServerMethodPre
Introduction
This section describes the instruction "OPC_UA_ServerMethodPre".
Because the instructions "OPC_UA_ServerMethodPre" and "OPC_UA_ServerMethodPost"
always have to be called up in pairs in the user program, please also take into account the
section on the instruction "OPC_UA_ServerMethodPost".
Function of the instruction
The instruction "OPC_UA_ServerMethodPre" queries the operating system to determine
whether or not the server method was called.
If the server method was called by the client, the instruction "OPC_UA_ServerMethodPre"
provides the input parameters for the server method.
Declaration of tags
Declare an instance of the instruction "OPC_UA_ServerMethodPre" and the tags with which
you supply the instruction parameters, see also Example program for providing a method for
OPC UA clients (Page 190).