Node-RED for Factory IoT: Visual Programming for Machine Data Flows

What Node-RED Is

Node-RED is a free, open-source visual programming tool built on Node.js. You build data flows by connecting nodes on a canvas — no writing code. A node for Modbus reads from your PLC, connects to a node that filters the data, connects to a node that writes to MySQL, and another that publishes to an MQTT broker. The entire pipeline is visible as a diagram.

Installing on a Factory Server

Node-RED runs on any Linux server, Raspberry Pi, or industrial PC. Install with npm install -g --unsafe-perm node-red. Access via browser on port 1880. Install community nodes for Modbus (node-red-contrib-modbus), OPC-UA (node-red-contrib-opcua), and MQTT (built-in). No licence required.

Common Factory IoT Flows We Build

PLC → MQTT → Dashboard: read Modbus register every second, publish to MQTT broker, subscribe in dashboard. Machine alarm flow: read alarm bit from PLC, when TRUE send WhatsApp via Twilio API. Shift summary email: at 06:00, 14:00, and 22:00 daily, query MySQL for shift totals, format as HTML email, send to distribution list.

Limitations of Node-RED

Node-RED is not suitable for very high-frequency data (>10 Hz per machine for many machines) — use a dedicated Node.js application for that. It is also not suitable for complex business logic — use proper application code. Node-RED shines for medium-complexity data flows where visual debugging and rapid iteration matter.