Owning Object and Relative Referencing

For an embedded symbol, you can specify an owning object. This allows you to associate the symbol with a cluster, tag or equipment reference. When you configure a symbol with relative references to an owning object, the embedded symbol will reflect values in the context of the owning object.

Example

A radial gauge symbol appears on the Industrial Graphics page named Overview in the Plant SCADA's ExampleSA project. If you open this page from the Visualization activity, it will appear in the Industrial Graphics Editor. Select the radio gauge object to view its Properties in the pane to the right of the editor.

• Owning Object:

  The OwningObject property in the Runtime Behaviour section has the value “Company.Library.Meter”. This is the Meter Equipment as defined in the project's equipment model. Any relative references will refer to this equipment.

• Relative Reference:

  In the example, the Max, Min and Value Custom properties are using relative references to equipment items "PRHigh", "PRLow" and "PV" respectively. This is indicated by the use of the "Me" reserved keyword.

  At runtime, "Me" will be substituted with the Owning Object reference. Using the "Value" property, with the value of "Me.PV" as an example, at runtime a subscription will be made not to Me.PV, but to Company.Library.Meter.PV.

Configure an Owning Object

Follow the steps to define a cluster, tag or equipment reference as the owning object for an embedded symbol.

1. Open a page in AIG Editor from the Visualization activity, and embed a symbol on it.

2. Select the embedded symbol to view the Properties section in the right-side pane.

3. Enter a cluster, tag or equipment reference in the OwningObject property of the Runtime Behaviour section.

4. Save and close the page.

Configure a Relative Reference

Relative referencing is adding references to the embedded symbol, so that in runtime the symbol will reflect the value of the owned object. Configure references using the "Me" keyword followed by the Tag, or Item, or partial Equipment.Item, as per the requirement. For example: Me.Tag1, Me.PV or Me.Equipment.PV.

Following are two methods to configure references to an embedded symbol:

• Hard-coding relative references of custom properties, animation expression, or script within the symbol

• Relative referencing in custom properties of an embedded symbol.

Hard coding Relative References of custom properties, animation expression, or script within the symbol

To hard code relative references:

5. Open a symbol in AIG Editor from the Visualization activity.

6. Open a Configuring a Value Display Animation for an element in the symbol.

7. Specify a relative reference “Me.<tag name/Item/Equipment.Item>" in Expression Or Reference. This should exist for the intended owning object expect to be set when the symbol is embedded. Click OK.

8. Save and close the symbol.

9. Open a page in AIG Editor from the Visualization activity.

10. Embed the symbol in the page, and specify an owning object for the symbol.

11. Save and close the page.

At runtime, the configured element will reflect the value of the owned object. If the owned object does not have the specified tag (in relative reference), you cannot reconfigure it in the page. Hence, in runtime, it will not reflect the <tag/item/equipment.item> value.

Relative Referencing in Custom Properties of an Embedded Symbol

To add relative reference for an embedded symbol:

12. Open a symbol in the Industrial Graphics Editor from the Visualization activity.

13. Configuring Custom Properties for the symbol.

14. Open a Configuring a Value Display Animation for an element in the symbol.

15. Specify the configured custom property in Expression Or Reference, and click OK.

16. Save and close the symbol.

17. Open a page in AIG Editor from the Visualization activity.

18. Embed the symbol in the page, and specify an owing object for the symbol.

19. Under Custom Properties specify the configured custom property value as “Me.<tag/item/equipment.item>”. This should exist for the specified owning object.

20. Save and close the page.

At runtime, the configured element will reflect the value of the resolved reference belonging to the owning object.