MQTT Topics and Publish Points
Last updated
Last updated
DCH generally uses one MQTT topic per data source for Gateway publishing, i.e. a gateway for a site would connect to the DCH broker using the DCH data source username and password, and then publish all messages under the same MQTT topic.
The topic structure is provided here:
Below is the example of a Niagara Jace device configured accordingly. This is also detailed in the Jace full DCH manual.
1. From the abstractMqttDriver palette, expand AbstractMqttPoints and drag an MqttStringPublishPoint into the Points folder of the Abstract Mqtt Driver Device. This point should have the Proxy Ext for MQTT.
2. Configure the Topic.
3. Device facets are typically defined in the JSON message and so this field should be left blank (the default).
4. Conversion and Tuning policy can be left as default.
5. Set the quality of service. It is recommended to set this to 0 (fire and forget) when publishing large amounts of points to reduce network traffic.
6. Retained is recommended to be set to true to assist with fault finding broker communications. If the connection is stale, the last message will be retained by the broker.
7. Publish message on change, leave as enabled (the default).
8. Enable the point and Save.
