Overview of the MQTT Sparkplug B Collector

Namespace/Groupname/<Message Type>/NodeID/<DeviceID>

spBv1.0/MyAdminGroup/NBIRTH/AdminNode1/ABC-12345

• MQTT V5
• MQTT V3.1.1

• Sparkplug B V1.0

• You can subscribe to multiple-level topics based on Sparkplug B paylod using a wildcard.
• You can collect time-series data.
• You can specify a device or node from which you need to collect data from.
• You can collect the data more specifically by providing device ID, node ID, and group ID.
• You can configure tag mask as needed by selecting the interfacename, groupid, edge nodeid, deviceid along with delimiter.
• You can select what tags you want to be added in Historian by using Tags to Add mask.
• You can select what tags you do not want to be added in Historian by using Tags to Exclude mask.
• Only the unsolicited data collection is supported; polled collection is not supported.
• The timestamp resolution is seconds, milliseconds, and microseconds.
• Boolean, floating point, integer, and string data types are supported.
  Note: Although the Recalculate button in Historian Administrator is enabled, the functionality is not available because the MQTT collector is a non-historic collector (the source broker does not store the historical data).

1. The Publisher connects to the MQTT Broker and subscribes to topics. The topics include STATE, NCMD, and DCMD.
2. The MQTT Sparkplug B collector connects to the MQTT broker and subscribes to a topic based on the Device ID and Node Id that you provide while creating an instance. The topics include STATE, NBIRTH, DBIRTH, NDATA, DDATA, NDEATH, and DDEATH.
   You can use username/password-based authentication or certificate-based authentication. Transport Layer Security (TLS) authentication is used for subscribing the data from message broker to avoid middleware attacks so that the data is securely transferred from message broker to the MQTT Sparkplug B collector.

   Note: It is recommended to use a certificate based authentication for a secured data transfer.
3. The MQTT Sparkplug B collector publishes the STATE message topic to the MQTT Broker.
4. The MQTT Broker then publishes this topic to the Publisher.
5. When there is data in the Device or Node, the publisher publishes a DBIRTH or NBIRTH message topic to the MQTT Broker.
6. The MQTT Broker then publishes this topic to the MQTT Sparkplug B collector.
7. The Publisher then publishes the DDATA or NDATA to the MQTT Broker.
8. The MQTT Broker publishes the data (metrics) to the MQTT Sparkplug B collector.
9. The collector converts the data from the Sparkplug B v1.0 format to a Historian-understandable format. It verifies tag availability in the Historian and, if not present, adds the tag, then adds the data samples, streaming the data to the Historian server or a cloud destination.

   The process explains how the topics and data are published among the Publisher, MQTT Sparkplug B collector, and MQTT Broker. Similarly, when there is no data or a Device or Node is inactive, the Publisher publishes DDEATH or NDEATH message topics to the MQTT Spakplug B collector through the MQTT Broker.

   Note: Sometimes, the publisher might send DDATA or NDATA without sending the corresponding BIRTH message, in such cases, the MQTT Sparkplug B collect sends the DCMD or NCMD message to the MQTT Broker. The the Broker sends the message to the publisher.
   
   

   Sparkplug B Message format:

   {
           "timestamp": <timestamp>,
           "metrics": [{
               "name": "<metric>",
               "alias": <alias>,
               "timestamp": <timestamp>,
               "dataType": "<data Type>",
               "value": "<value>"
           }],
           "seq": <sequence_number>
   }