Querying Raw Data

About this task

Raw data values are the values actually stored in the archive, after applying collector and archive compression, but before applying any interpolation, smoothing, or other signal processing calculations. Querying raw data retrieves these values for a selected tag.

The raw data query returns a number of data points based on the number of rows or columns specified in the output range. If you are not viewing all your data points, select enough rows or columns to display all the data.

Procedure

Select Query Raw Data from the Historian menu.
The Historian Raw Data Query dialog box appears.
Select a server from the drop-down list. If you do not specify a server, the Add-In queries the default server.
To set the selected server as default, ensure the Set Server to Default option is enabled.
Select a tag on your worksheet and, while it is selected, click in the Tag Name field of the dialog box.
This enters the tag name for you automatically. You can also enter the tag names manually in the Tag Name field of the dialog box.
Optionally, you can select the tag from the Advance Tag Search dialog. For more information, refer to Advance Tag Search topic.
In the Query Type section, select the type of data search from three options:
- By Time Search for data values between a start time and an end time. You must enter values for starting and ending times in the fields displayed at the right of the option. You can also use relative time entries to this field. For more information, refer to Relative Time Entries
- By Number Forward Search for a number of values after a specified time. Enter values into the After Time and Number of Values fields.
- By Number Backward Search for a number of values before a specified time. The display changes from start and end times to Values Before Time and Number of Values. Enter appropriate parameters in these fields.
In the Query Criteria String, enter the query criteria along with the # symbol.
For example, if the query criteria string is to retrieve only good data quality values, then you should specify #ONLYGOOD as the Query Criteria String. For more information, see Query Modifiers.
In the Output Display field, select one or more parameters for the output.
To select multiple individual tags, press the Control key and click the tag names.
To select a sequence of tags, press the Shift key and click the first and last tag name of the sequence.
Click in the Output Range field and select a range of cells in a single row or column to determine where the returned data is placed.
Select either Columns or Rows for the output display.
Selecting Columns displays a table of values with parameters arranged in columns with header labels at the top. Selecting Rows rotates the table 90 degrees.
Select either Ascending or Descending to set the order of the retrieved data in either ascending or descending order.
Click OK to initiate the query. Click Cancel to abort the operation and close the dialog.

Note: For an Array Tag, each element is displayed in separate rows with the tag name and index.