node-opcua-client

import { OPCUAClient, MessageSecurityMode, SecurityPolicy, AttributeIds } from "node-opcua-client"; async function main() { // Use process.env.OPCUA_SERVER_ENDPOINT_URL for flexibility, fallback to localhost const endpointUrl = process.env.OPCUA_SERVER_ENDPOINT_URL ?? "opc.tcp://localhost:4840"; // Create an OPC UA client instance const client = OPCUAClient.create({ endpointUrl: endpointUrl, securityMode: MessageSecurityMode.None, // No security for simplicity (dev/test) securityPolicy: SecurityPolicy.None, // No security policy connectionStrategy: { maxRetry: 10, initialDelay: 2000, maxDelay: 10 * 1000 } }); try { // Connect the client to the OPC UA server await client.connect(endpointUrl); console.log("Client connected to endpoint:", endpointUrl); // Create a session with the server const session = await client.createSession(); console.log("Session created with ID:", session.sessionId.toString()); // Define the NodeId to read (e.g., Server_ServerStatus_CurrentTime) const nodeIdToRead = "ns=0;i=2258"; // Read the value of the specified node const dataValue = await session.read({ nodeId: nodeIdToRead, attributeId: AttributeIds.Value }); console.log(`Value of ${nodeIdToRead}: ${dataValue.value.value}`); // Close the session and disconnect the client await session.close(); console.log("Session closed."); await client.disconnect(); console.log("Client disconnected."); } catch (err) { console.error("An error occurred during OPC UA operations:", err); process.exit(1); } } main();