Connecting Siemens LOGO 8.4 PLC to Blynk via HiveMQ Cloud Serverless

Question

🧩 Summary

Customers using HiveMQ Cloud Serverless or Starter plans may experience issues integrating MQTT devices like Siemens LOGO 8.4 PLC with platforms such as Blynk due to incompatible payload formats.

❓ Problem

• Blynk expects specific MQTT payload formats (e.g., JSON key-value pairs for virtual pins).

• Siemens LOGO publishes messages in a format not directly consumable by Blynk.

• HiveMQ Cloud Serverless does not offer built-in data transformation capabilities.

Answer

Option 1: Use a Payload Transformation Bridge (e.g., Node-RED)

The most practical workaround on the Serverless plan is to use Node-RED as an MQTT bridge between Siemens LOGO and Blynk. This allows you to transform message formats between the two systems to ensure compatibility.

🔗 Blynk MQTT API Reference: Blynk Device MQTT API

🚀 Option 2: Upgrade to HiveMQ Enterprise (with Data Hub)

For production use cases or commercial integrations, consider upgrading to HiveMQ Enterprise, which includes:

• Data Hub

• Real-time message transformation and enrichment

• Declarative transformation pipelines (e.g., JSONPath, Groovy)

🔗 Learn more: HiveMQ Data Hub Transformations

🔐 Limitations of HiveMQ Cloud Serverless/Starter