The relations feature provides the mechanism for structuring relationships among points in a hierarchy.
A relationship exists between two components. A parent component has one or more child relationships. The collection of data
flows from one point to another based on the relationship between points. There are two types of relations:
- Direct relations are those that you apply (using relation markers) directly to a point. These relations are defined in a tag
dictionary. The query configured by a relation definition on a hierarchy causes the system to return data.
- Implied relations are defined by tag rules in a Smart Tag Dictionary and applied automatically by the system. The query configured
by a relation definition on a hierarchy causes the Smart Tag Dictionary to interpret the tag rules against the given point
and return a list of implied relations.
You establish relationships in two places:
- By placing relations markers on points. These identify parent and child points.
- By adding relation level definitions to hierarchies set up where the system searches for data beyond the individual point.
Relations themselves may be tagged. The Niagara Relations Guide describes more fully how to set up relationships.