Adding items to opc-ua server contrib-opcua

[nico25]

Hi all,

we installed counters for compressed-air-usage here in our factory, after getting their values into nodered,
now i want to make their values available for third party software by opc-ua.

I set up a OPC-UA server using contrib opc-ua. Now i am having trouble to add items/variables to the server.

this is what my flow looks like:

Item Node:

Server-Node:

Available tree in third party software:

Are there additonal things in my flow needed to have the variables appear in the tree?
Maybe somebody can provide a sample flow, where variables are added to the OPC-server.
Server connection works fine.

[mikakaraila]

Look examples folder and file OPCUA-TEST-NODES.json
It contains multiple examples and also addFolder and addVariable commands.

[nico25]

You meant the examples section in the nodered GUI? OPCUA doesn´t appear there for me.
Would you be so kind and copy paste a flow here for me?

Edit: Found it on your github

[nico25]

After some playing around I was able to create a folder on the OPCUA-Server and store variables/values there. So first progress Now I am curious about the servers behaviour in case of powerloss/ nodered crash.
I adressed the variables by their indentifiers after creating them on serverside.

Are these identifiers persistent after being created once or am I going to run into trouble?
Because I tried restarting the server and saw that it initially came back "empty", and all folders and variables had to be set again?

[mikakaraila]

Use inject node that will always inject once as flow starts.
Another option is to save XML and then load it always as server starts.
Study examples and OPCUA-TEST-NODES.json there is tab with server.

[nico25]

Hi Mika,

I am trying the XML-way right now, but when try to save the xml, i get a warning and nothing is written to the xml:

[mikakaraila]

This one works, so check your path that folder is existing and you have access rights to write file.

[nico25]

I tried again and made sure there is access to the file, but i´m still stuck with the same error.

I know the following screenshot is in german but it says: Access: Read & Write

[mikakaraila]

Try relative path as I have tested this case.

[mikakaraila]

Code checks only msg.payload & msg.filename are defined. Optional msg.topic is used to save different namespaces.

 case "saveAddressSpace":
                        if (msg.payload && msg.filename) {
                            // Save current server namespace objects to file
                            var namespace = addressSpace.getOwnNamespace(); 
                            // Use msg.topic to select namespace
                            if (msg.topic) {
                                verbose_log("Saving namespace index: " + msg.topic);
                                namespace = addressSpace.getNamespace(parseInt(msg.topic));
                            }
                            if (namespace) {
                                const xmlstr = namespace.toNodeset2XML();
                                fs.writeFileSync(msg.filename, xmlstr.toString(), {encoding: "utf8"});
                            }
                            else {
                                verbose_warn("No namespace to save to XML file, check namespace index: " + msg.topic);
                            }
                        }
                        else {
                            verbose_warn("Check msg object, it must contain msg.filename for the address space in XML format!");
                        }
                        break;