Data discovery parameters

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Last UpdatedNov 14, 2025
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The following parameters are available for configuring data source discovery for Sparkplug B:

Parameter	Type	Description
id	string	The identification of the discovery. Note: You cannot run multiple discoveries with the same id. Including an id is optional. If you do not include one, the adapter automatically generates one.
query	string	A filter that is specific to the data source. The query filter can limit the scope of the discovery. For more information, see Query filter for Sparkplug B data source discovery.
startTime	datetime	Time when the discovery started.
endTime	datetime	Time when the discovery ended.
progress	double	Progress of the discovery.
itemsFound	integer	Number of data items that the discovery found on the data source.
newItems	integer	Number of new data items that the discovery found in comparison to the previous discovery.
resultUrl	integer	URL at which you can access the results of the discovery.
autoSelect	boolean	When set to true, the result of the discovery gets pushed to the data selection configuration.
status	reference	Status of the discovery, for example Active or Complete.
errors	string	Errors encountered during the discovery.

Query filter for Sparkplug B Data source discovery

A discovery against the data source of an MQTT Sparkplug B adapter allows you to specify the optional query parameter. The query discovers the contents of the data source and narrows down the scope of the discovery. You can add the discovered items to the data selection.

Sparkplug B query string

The string of the query parameter must contain string items in the following form:

Topics=Topic1,Topic2;WaitTime=<WaitTime>

where the Sparkplug B topic structure is of the form

topics=spBv1.0/<Group_Id>/<Message_Type>/<Edge_Node_Id>/<[Device_Id]>

Note: Device Id is optional in the SparkplugB topic structure.

String item	Required	Description
Topics	Optional	The topics that the adapter subscribes to when the discovery posts. Note: If you want to specify multiple topics in the query, you must separate the topic names with a comma. If you do not specify a topic, the adapter subscribes to all topics.
Group_Id	Optional	This element of the Topic namespace logically groups MQTT Edge of Network (EoN) nodes into the MQTT server and the consuming MQTT clients.
Message_Type	Optional	This element of the Topic namespace indicates how to handle the MQTT payload of the message. The message type is typically NDATA or DDATA. For more information, see Data selection.
Edge_Node_Id	Optional	This element of the Sparkplug Topic namespace uniquely identifies the MQTT EoN node within the infrastructure. Group_Id combined with Edge_Node_Id must be unique from any other Group_Id/Edge_Node_Id assigned in the MQTT infrastructure.
Device_Id	Optional	This element of the Sparkplug Topic namespace identifies a device attached to the MQTT EoN node (physically or logically).
WaitTime	Optional	The time window in which the adapter will perform the discovery by listening for specified topics. After the wait time has elapsed, the discovery results will be available. Minimum value: 0.00:00:30 (30 seconds) Maximum value: 7.00:00:00 (7 days) Note: If you do not specify a wait time, the default value 0.00:01:00 (1 minute) will be applied. When you specify WaitTime with a numeric value, for example WaitTime=45, the adapter interprets the value as seconds instead of time span.

Query rules

The following rules apply for specifying the query string:

Multiple topics are separated by a comma (,).
A query cannot be terminated by a trailing slash (/).
A query cannot start with a leading slash (/) or $.
Topics are case sensitive.

Note: The data source might contain large amounts of metrics. Use the # judiciously and narrow down the query string to something specific or break down the query into different discoveries.

Wildcards

Wildcards are allowed in the query with the following specifications:

A single-level wildcard replaces one topic level and is indicated by +.
A multi-level wildcard covers many topic levels and is indicated by #.
Wildcards can be combined.
# must not be used more than once and can only be used at the end of the topic.
No query, an empty string, or null as the query parameter is equivalent to #.

AVEVA™ Adapter for MQTT