demo-opcua1.js

// demo-opcua1.js
Servient = require("@node-wot/core").Servient;
OPCUAClientFactory = require("@node-wot/binding-opcua").OPCUAClientFactory;

const thingDescription = {
    "@context": "https://www.w3.org/2019/wot/td/v1",
    "@type": ["Thing"],
    securityDefinitions: { nosec_sc: { scheme: "nosec" } },
    security: "nosec_sc",
    title: "servient",
    description: "node-wot CLI Servient",
    properties: {
        pumpSpeed: {
            description: "the pump speed",
            type: "number",
            forms: [
                {
                    href: "opc.tcp://opcuademo.sterfive.com:26543", // endpoint,
                    op: ["readproperty", "observeproperty"],
                    "opcua:nodeId": "ns=1;s=PumpSpeed",
                },
            ],
        },
    },
};

(async () => {
    const servient = new Servient();
    servient.addClientFactory(new OPCUAClientFactory());

    const wot = await servient.start();

    const thing = await wot.consume(thingDescription);

    const content = await thing.readProperty("pumpSpeed");
    const value = await content.value();
    if (value != null) {
        const json = (value).valueOf();
        console.log("Pump Speed is", json);
    }

    await servient.shutdown();

})();