Definition
MQTT is a lightweight publish-subscribe messaging protocol designed to send small amounts of data efficiently, especially over constrained or unreliable networks: a device publishes data to a named topic, and any number of interested systems can subscribe to receive it, without a direct point-to-point connection between each publisher and subscriber.
Key facts
- Uses a publish-subscribe model, decoupling data publishers from subscribers, neither needs to know about the other directly.
- Designed to be lightweight and efficient, well-suited to constrained networks or many low-power IIoT devices.
- A common choice for sending sensor readings from many distributed devices to a central data historian, cloud platform, or monitoring system.
- Distinct from request-response protocols like Modbus, which require a direct query for each piece of data.
How does MQTT work in maintenance?
MQTT works on a publish-subscribe model: a device publishes a data value to a named topic on a central broker, and any system that has subscribed to that topic automatically receives the update, decoupling data producers and consumers and making it efficient to fan data out to multiple interested systems at once.
What does MQTT require?
MQTT's publish-subscribe model and lightweight design make it particularly well suited to IIoT scenarios with many distributed devices sending data efficiently to central systems, distinct from request-response protocols like Modbus or the structured, model-rich approach of OPC UA, though the three are often used together in a layered architecture.
FAQ
Frequently asked questions
What task does MQTT perform in message exchange?
MQTT sends small amounts of data efficiently using a publish-subscribe model, letting devices publish to a named topic that any number of interested systems can subscribe to, well suited to constrained networks and many IIoT devices.
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