Real-time machine monitoring via Node.js & Modbus.
Industrial controllers speak Modbus. Browsers speak HTTP. Bridging that gap with Node.js sockets and live data without polling — that is exactly the kind of technical challenge we go for.
Live shop-floor data in the browser — without delay.
Industrial machines communicate via the Modbus protocol over serial lines or TCP. The client wanted the status and readings of multiple controllers displayed live in a browser dashboard — for operators on the shop floor and for remote monitoring. The challenge: Modbus is a polling protocol, but the dashboard needed to work without constant page refreshes and had to support multiple simultaneous clients.
Node.js as the bridge between Modbus and the browser.
Modbus read layer in Node.js
A Node.js service reads the registers of the Modbus controllers via TCP at configurable intervals. The library choice and interval configuration are tuned to the specifications of the controllers involved. Read and write actions are serialised via a queue mechanism to prevent collisions.
WebSocket distribution
Each new Modbus reading is immediately pushed to all connected browser clients via a WebSocket connection. Clients receive updates without polling — the server pushes as soon as new data arrives. This keeps the dashboard responsive without unnecessary load on the controllers.
Live browser dashboard
The browser dashboard shows the current readings, status indicators and alarm conditions per controller. The UI is updated entirely client-side via WebSocket messages — no page reload, no latency from server-side rendering.
Robustness and reconnect logic
Both the Modbus connection and the WebSocket connection reconnect automatically after a dropped connection. The server logs connection events and keeps the last known values, so a reconnecting client immediately sees the current state.
The data flow.
Controller
Service
Push
Dashboard
Shop-floor data on any screen, in real time.
The platform simultaneously reads multiple industrial Modbus controllers and distributes the live data to an unlimited number of simultaneous browser clients. Operators see machine status and readings in real time, without page refreshes. The system automatically recovers from connection disruptions — both on the Modbus side and on the browser side.
More about web development →
Node.js · WebSockets · Modbus-TCP · JavaScript · real-time data architecture
Real-time, integrations, the impossible.
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