MQTT Transmission

I can’t seem to find a way to change the default messaging format from SparkPlugB to customisable JSON? Ideally we would like to keep the one same MQTT topic for the whole project and just change the message payload per tag to include metadata and ts / value pair JSON data.

You can specify Sparkplug JSON as the Data Format Type in MQTT Transmission Configuration. You can find this setting under Config → MQTT Transmission Settings → Servers → Settings → [Your Server Setting] → Advanced → Data Format Type.

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A few additional comments…

  • MQTT Engine does not support Sparkplug JSON, only Sparkplug Protobuf. Sparkplug JSON is typically used when sending data to external data consumers that do not support Sparkplug Protobuf.
  • MQTT Transmission does not support customizing the message payload to include additional metadata. However, you can add custom tag properties in Ignition that will get picked up and published by Transmission.
  • MQTT Transmission message topics are also not customizable beyond the ability to specify Sparkplug IDs (GroupId, EdgenodeId, DeviceId) which are used in the Transmission message topics.