Simple sample: OPC_UA_ReadList_C and OPC_UA_WriteList_C for OPC UA client communication

Starting with STEP 7 V17, two new instructions for using S7-1500 in communication as OPC UA Client are available: OPC_UA_ReadList_C and OPC_UA_WriteList_C.

These two blocks manage the establishment and finalization of connections, integrating in a single block what could before be done just by a set of blocks (OPC_UA_Connect, OPC_UA_NamesapceGetIndexList, OPC_UA_NodeGetHandleList, OPC_UA_NodeReleaseHandle, OPC_UA_Disconnect).

In terms of usage, they are like OPC_UA_ReadList / OPC_UA_WriteList: just insert the block into the program, click on the toolbox and fill in the options.

Tips:

• The general configuration flow is described in “TIP: S7-1500 OPC UA Server Client communication, exporting XML files” (https://support.industry.siemens.com/tf//br/en/posts/tip- s7-1500-opc-ua-server-client-communication-exporting-xml-files / 201866 /? page = 1 & pageSize = 10)
• After defining the read list and before calling the read / write blocks, it is interesting to compile the project. In this way, the communication DB variables will be available for the block configuration.

Attached a sample project