Tips and best practices for working with Entities and Dashboards

Getting started

Most sites connected to the Ardexa cloud can be modelled with a simple representation in the entity system. Ardexa's original two-level device/source hierarchy can be recreated by creating a site/device-level entity for each device, then creating a sub-entity for each source underneath it. Creating and applying site-level and source-level labels will then let you create generic label-based dashboards to reuse throughout the workgroup.

Signals vs Sub-entities

When creating entities for a site, deciding whether to add a source as a signal to an existing entity, or create a new sub-entity is an important and initially un-intuitive decision.

Single vs Multiple data streams

Entities work best when a given table + field combination resolves to a single source that belongs to the entity. Assigning two sources that contain the same table + field can lead to conflicts which will prevent dashboards from working as expected. To avoid this conflict, it is best to create one or more sub-entities to contain the conflicting source(s).

For example, if you were monitoring an electricity meter at a site, which was collected as source meter-01 to the table/field meter.AC Power, you can initially assign it to the site's entity as a signal. This will allow it to be easily referenced in dashboards, and keeps the entity tree simple.

If a second meter were to be connected to the device, that also collected meter.AC Power, you should then create a child entity underneath the site from the meter-02 source. You can optionally do the same for meter-01. You will then be able to refer to Meter 1 -> meter.AC Power and Meter 2 -> meter.AC Power independently.

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