The add-on has single configuration, datasource. Datasource contains information to connect to a specific database and you can define multiple datasources. Some custom fields of the add-on needs to connect to database and defining all database connection information in centralized location will simply adding new custom fields. You don't need to define datasource for each field separately, a single datasource can be shared between multiple fields.
Clicking on 'Datasource' link under 'Custom Fields++' section of add-on administration page displays list of existing datasources.
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