As part of the remote monitoring solution for my digital twin, I integrated Node-RED to create a lightweight IIoT dashboard for real-time system observation. In this post, I’ll cover how I installed Node-RED and configured it to communicate with TIA Portal v19 and PLCSIM Advanced using OPC UA. 

Why Node-RED?

Node-RED is an open-source, flow-based programming tool initially developed by IBM. It’s designed for IIoT and edge computing applications, making it perfect for building dashboards and connecting industrial data without writing traditional code.

In my project, Node-RED allows browser-based visualisation of:

• Workpiece counters

• Station status

• Sensor/actuator feedback

• Fault conditions

All without interfering with the PLC logic—purely read-only monitoring for safety and clarity.

Installation Steps

1. Install Node.js

Node-RED runs on Node.js. First, install the LTS version of Node.js:

• Download from: https://nodejs.org

• Use the default installation settings

Once installed, confirm via terminal/command prompt:

node -v

npm -v

2. Install Node-RED

With Node.js installed, open a terminal and run:

npm install -g --unsafe-perm node-red

Once installed, you can launch it anytime with:

node-red

Then open your browser at: http://localhost:1880

Configuring for Siemens OPC UA (TIA Portal + PLCSIM Advanced)

To access data from your virtual PLC, Node-RED needs to communicate via OPC UA, a widely used industrial protocol.

1. Install OPC UA Nodes

In Node-RED, go to Menu → Manage Palette → Install and search for:

• node-red-contrib-opcua

Install it. This gives you OPC UA Client, Items, and Connector nodes.

2. PLCSIM Advanced OPC UA Setup

Before Node-RED can connect:

• In PLCSIM Advanced, enable the OPC UA Server (typically via settings/configurator).

• Set a static IP address for the virtual PLC (e.g. 192.168.0.1)

• Note the endpoint URL, usually: opc.tcp://192.168.0.1:4840

3. TIA Portal OPC UA Configuration

• In TIA Portal, go to the PLC project > Add Communication → OPC UA Server

• Add OPC UA Runtime License - SIMATIC OPC UA S7-1500 small

• Create symbolic tags and ensure they’re marked for OPC UA exposure

• Download the configuration to PLCSIM Advanced.

Test with UA Expert (optional):
Before using Node-RED, you can test connectivity and browse tags using UA Expert (a free OPC UA client from Unified Automation).

Summary

By the end of this step:

• Node-RED is installed and running locally

• The OPC UA palette is available

• TIA Portal and PLCSIM Advanced are configured to expose PLC tags

• You’re ready to create Node-RED flows to connect, read, and visualise the data!