Registry / web-framework / node-red-contrib-opcua

node-red-contrib-opcua

library0.2.351jsnpmunverified

A Node-RED node collection for OPC UA communication and server functionality, based on the node-opcua library. Current stable version is 0.2.351, released regularly with active maintenance. It provides client nodes to read, write, subscribe, browse, and invoke methods on OPC UA servers, plus server nodes to create variable and method nodes. Key differentiators include tight integration with Node-RED's flow-based programming model and support for complex OPC UA features like subscriptions, monitored items, events, and array index ranges. Compared to generic OPC UA SDKs, it abstracts connection management and message parsing into easy-to-configure nodes.

web-framework communication data

npm install node-red-contrib-opcua

github ↗package ↗

INSTALL

IMPORT

SIG · NODE-RED-CONTRIB-O

node-red-contrib-opcua

web-frameworkjavascriptv0.2.351

Install

—

Import

—

Disk

—

Pass rate

0/ 6

Env Coverage0 / 6

glibc

18–22

musl

18–22

Install & Compatibility

Where this runs

tested against v? · npm install

Install × environment matrix

Each cell = how many times install + import succeeded across repeated harness runs. Partial = flaky.
glibc = Debian/Ubuntu slim · musl = Alpine Linux

musl

node 18–226 runs

build_error

glibc

node 18–226 runs

build_error

Code

Verified usage

Verified import paths — ran on the pinned version, not inferred.

OpcUa-Client

✓ import the node via Node-RED palette after installation

✗ const OpcUaClient = require('node-red-contrib-opcua')

This is a Node-RED node, not a library. Import is done automatically by Node-RED after npm install.

OpcUa-Item

✓ import the node via Node-RED palette after installation

✗ import { OpcUaItem } from 'node-red-contrib-opcua'

Nodes are registered with Node-RED and appear in the palette. No manual import needed.

OpcUa-Server

✓ import the node via Node-RED palette after installation

✗ const server = require('node-red-contrib-opcua').OpcUaServer

Only install the package; Node-RED handles node registration.

Installation and minimal flow to read an OPC UA variable using OpcUa-Client and OpcUa-Item nodes.

// No code snippets needed - this is a Node-RED node collection. // To use: Install Node-RED, then run: // npm install node-red-contrib-opcua // Then in Node-RED flows, drag OpcUa-Client, OpcUa-Item, OpcUa-Server nodes. // Example flow (JSON) to read a variable: // [{"id":"n1","type":"OpcUa-Item","name":"example-item","topic":"ns=2;s=MyVariable","datatype":"Int32"}, // {"id":"n2","type":"OpcUa-Client","name":"example-client","endpoint":"opc.tcp://localhost:4840","action":"read","items":["n1"]}, // {"id":"n3","type":"inject","name":"trigger","topic":"","payload":"","repeat":"","crontab":"",once":false}, // {"id":"n4","type":"debug","name":"output"}, // {"id":"n3","wires":[["n2"]]}, {"id":"n2","wires":[["n4"]]}]

Debug

Known issues

breakingFrom v0.2.223, namespace index used with variables for set value; flows using older version may need adjustment.

fix

Update to v0.2.223+ and ensure variable nodes have correct namespace index.

affects: <0.2.223

deprecatedThe node-opcua library has undergone major API changes; some deprecated methods may cause warnings.

fix

Update to latest node-opcua and this package, check node-opcua migration guides.

affects: >=0.2.300

gotchaPayload must include both nodeId and datatype in topic field for read/write operations.

fix

Format topic as 'ns=<namespace>;s=<identifier>;datatype=<DataType>' (e.g., 'ns=3;s=Counter;datatype=Int32').

affects: all

breakingNode.js 15 minimum required (engines field). Older Node.js versions may cause installation failures.

fix

Upgrade Node.js to version 15 or later.

affects: >=0.2.0

gotchaFirewall blocks: OPC UA uses dynamic ports for discovery; ensure network allows OPC UA TCP (port 4840 by default) and discovery endpoints.

fix

Configure firewall to allow OPC UA traffic, or set specific client/server ports.

affects: all

deprecatedaction field 'monitor' is deprecated; use 'subscribe' instead.

fix

Use action='subscribe' with interval and queueSize parameters.

affects: >=0.2.300

Errors

Common errors & fixes

Error: Cannot find module 'node-opcua'

Missing or incomplete installation of node-opcua dependency.

fix

Run 'npm install node-opcua' in the Node-RED user directory or globally.

Error: connect ECONNREFUSED <ip>:4840

OPC UA server is not running or is blocked by firewall.

fix

Check OPC UA server status and ensure port 4840 is open on server and client firewall.

BadNodeIdInvalid: BadNodeIdInvalid

The nodeId string format is incorrect.

fix

Ensure nodeId follows pattern 'ns=<namespaceIndex>;<identifierType>=<identifier>' (e.g., 'ns=2;s=MyVariable').

StatusCode: BadSessionIdInvalid

Session expired or invalid session token.

fix

Reconnect the OpcUa-Client node (e.g., deploy flow again or trigger reconnect).

SecurityError: Certificate verification failed

OPC UA client certificate rejected by server (PKI issue).

fix

Place client's self-signed certificate in server's trusted certificate store, or disable certificate verification (not recommended).

Upgrade

Version history

0.2.351latest on npm

Audit

Dependencies

node-opcuarequiredCore OPC UA protocol implementation

node-redrequiredRequired runtime environment

Agent activity

13 hits · last 30 days

node

OpenAI (training)

Resources

githubhttps://github.com/mikakaraila/node-red-contrib-opcua ↗

packagehttps://www.npmjs.com/package/node-red-contrib-opcua ↗