Configuring the MQTT Publish and Subscribe Nodes in Node-Red

Node-Red provides both an MQTT subscribe (input) and publish (output) node. The configuration for these nodes are almost Identical as the main part of the configuration concerns the actual client connection. Because of this it is useful to think of the publish and subscribe nodes as consisting of two components as shown in the schematic below: Before we look a the actual configuration we will look at MQTT client connections in general.

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Storing Data in Node-Red Variables

Node-red nodes pass the msg object between nodes. However this object is replaced by the next msg object. So how do you store data between node calls? Node-Red provides three mechanisms: The context object -stores data for a node The Flow object – stores data for a flow The global object -stores data for the canvas

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