Tag Query Tab
Context
You use the Tag Query tab to specify the tags required for the query in the query process.
Procedure
- On the Plant Connectivity Management Console screen, select an agent instance and click on the Tag Query tab.
- For information you need to enter, use the following table:
Field
Description
Cache Mode
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Access to Data Source Only
With this setting, all data is retrieved directly from the data source for queries. With this setting, performance is slowest.
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Access to Cache, to Data Source as Required
With this setting, for a query, the cache is first checked to see whether there are tags and metadata. If not, the tags are retrieved from the data source and added to the cache.
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Access Using Aliases Only
You use this setting if you have previously created an alias for the source system. An alias is a user-defined structure for tags, metadata, and secondary elements. The alias is loaded when the agent starts. See also: Source System: Aliases Tab.
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Access to Cache Only
With this setting, all tags are queried from the data source and stored in the cache. Metadata is retrieved when a tag is requested.
Mask
Here you can restrict selection of the tags. For example, if you specify INT*, only those tags whose name begins with Int are chosen from the source system.
Note: This field is only valid in combination with the cache mode Cache. See: Filter Functions.
Alias
Name of the alias file to be used.
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