Mqtt
Node Documentation
Connects to a MQTT broker and subscribes to messages from the specified topic.
Outputs
- payload string | buffer
- a string unless detected as a binary buffer.
- topic string
- the MQTT topic, uses / as a hierarchy separator.
- qos number
- 0, fire and forget - 1, at least once - 2, once and once only.
- retain boolean
- true indicates the message was retained and may be old.
- responseTopic string
- MQTTv5: the MQTT response topic for the message
- correlationData Buffer
- MQTTv5: the correlation data for the message
- contentType string
- MQTTv5: the content-type of the payload
- userProperties object
- MQTTv5: any user properties of the message
- messageExpiryInterval number
- MQTTv5: the expiry time, in seconds, of the message
Details
This node requires a connection to a MQTT broker to be configured. This is configured by clicking the pencil icon.
Several MQTT nodes (in or out) can share the same broker connection if required.
Dynamic Subscription
Inputs
These only apply when the node has been configured for dynamic subscriptions.
- action string
- the name of the action the node should perform. Available actions are:
"connect",
"disconnect", "subscribe" and "unsubscribe".
- topic string|object|array
- For the
"subscribe" and "unsubscribe" actions, this property provides the topic. It can be set as either:
- a String containing the topic filter
- an Object containing
topic and qos properties
- an array of either strings or objects to handle multiple topics in one
- broker broker
- For the
"connect" action, this property can override any of the individual broker configuration settings, including:
brokerporturl - overrides broker/port to provide a complete connection urlusernamepassword
If this property is set and the broker is already connected an error will be logged unless it has the force property set - in which case it will disconnect from the broker, apply the new settings and reconnect.