About transform graphs

A series transform graph is a node container that holds all other graph nodes. The transform graph node itself is also a graph node that contains other transform graphs. This makes it possible to create transform graphs that provide very specific data functionality, and use them as building blocks to create larger graphs.

After you add a transform graph node to your station, double-clicking on it opens the node’s default Wire Sheet view where you can configure graph properties. When properly configured, a series transform graph performs a transformation or series of transformations against a set of data to produce a single result.

Figure 13.   Transform graph component
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Working with transform graph nodes:

  • To define the data schema, each node must contain a single terminal node plus one or more source nodes. Source nodes may be HistorySource nodes or other transform graph nodes.
  • Each node returns a single result and thus contains a single terminal node.
  • Nodes may contain one or more transformation-type node(s), such as the Aggregate, Rollup, Scale, or Composite nodes.
  • Transform graphs may be included as transformations within other transform graphs.
  • To resolve a configured transform graph node in Workbench (to see a table view of the source data) right-click on the transform graph node in the Nav tree and select Resolve Graph from the popup menu.
  • To see a configured transform graph node as a chart or as a table in a Px page, use the PxEditor Make Widget Wizard.

The following illustrations show some example transform graph implementations.

Figure 14.   A graph containing graph nodes
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Figure 15.   A graph containing another graph as a source
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Figure 16.   Two interconnected graphs. The first graph acts as data source for the second.
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