This binding type (which is only available for Dataset type properties), will run a query against the SQLTags Historian.
Selected Historical Tags
For this type of query, you must select at least one tag path to query. The Dataset returned by the query will have a timestamp column, and then a column for each path that you select here.
These paths may use indirection following the same rules as the Indirect Tag Binding. Simply type the indirection parameters (e.g. {1}) into a selected tag path by double-clicking in the list of selected paths. All valid parameters will appear in the lower indirection table.
Date Range
Choose either a Historical or Realtime query. Historical queries use a date range that must be bound in from other components on the screen, typically a Date Range or a pair of Popup Calendars. Realtime queries always pull up a range that ends with the current time, so all they need is a length.
Sample Size and Aggregation Mode
The sample size determines how the query results will look. A Natural query will look up the logging rate for the queried tags, and return results spaced apart at that rate. This means that the return size will vary with the date range. An On Change query will return points as they were logged. This means that the results may not be evenly spaced. A Fixed query will return the given number of rows. Where data was sparse, interpolated values will be added. Where data is dense, the Aggregation Mode will come into play.
The Min/Max aggregation mode will return the min and max for every timestamp. The Average aggregation mode will return the average timestamp for data within the underlying range.
Return Format
Return format dictates how the requested data will be returned. The options are "wide" (default), in which each tag has its own column, and "tall", in which the tags are returned vertically in a "path, value, quality, timestamp" schema.
SQLTags Historian information is often easiest to work with in the Easy Chart component, which handles all of these options automatically.
See also: