Publishing Data via MQTT with vNode: A Step-by-Step Guide

Guide: Publishing Data to MQTT Using vNode (English)

✅ Requirements

Make sure you have the following before starting:

• vNode installed and running

• Access to an MQTT broker (local or cloud)

• A real or simulated tag to publish

• Broker details:

  • IP address or hostname

  • Port (1883 or 8883)

  • Username/password (if required)

  • Certificates (for TLS, if applicable)

  • Topic structure you want to use

✅ Step 1: Create the MQTT Client Module

1. Go to the Config section in the vNode interface.

2. In the Explorer panel, expand Modules.

3. Right-click and select New Module.

4. Name the module (e.g., mqtt).

5. In Module Type, select mqttclient.

✅ Step 2: Configure MQTT Connection

1. After creation, the module will appear under Modules in the Explorer.

2. Click on it and fill in the required fields:

   • MQTT Version: 3.x or 5

   • Broker Type: Custom (for Mosquitto or generic brokers)

   • Authentication Type: None if credentials aren't required

   • Protocol: mqtt or mqtts

   • Broker URL: use 127.0.0.1 or localhost for Mosquitto

   • Port: typically 1883
     
     
     
     
     

? Mosquitto is available at: https://mosquitto.org/download/

✅ Step 3: Add a Publisher Agent

1. In the module, go to the Agents section.

2. Add a new agent of type Publisher.

3. Configure the following:

   • Trigger Type: Events

   • Interval (ms): 1000 or as required

   • Topic: e.g. Plant/Temperature or any topic you need

   • Message Format:

     • Use JSON to send vNode's default format

     • Use Custom if you want to define a specific JSON structure
       
       
       

✅ Step 4: Select tags to publish

1. In the Tag Filter, select the tags to be published.

2. Only those tags will be sent to the broker.
   
   
   

⚠️ Event-based publishing means only values that change will be transmitted within the defined interval.

✅ Result

Once deployed, vNode will begin publishing data to the broker under the configured topics, ready for any MQTT subscriber to receive.

✅ Communication Test

To verify that vNode is publishing correctly to the MQTT broker, you can use a client tool such as MQTT Explorer.

? Download it from the official website:
? https://mqtt-explorer.com

This tool lets you view topics, live data, and message structure in real time, helping you confirm that your vNode instance is communicating properly.

Created by JF