Use the Criteria tab

Use the Criteria tab to specify the filtering criteria for the data value(s) to be returned.

The filtering criteria options are determined by what you selected for the display format for the returned data, either "narrow" or "wide." For more information, see Format Tab.

For tag based criteria (wide tables), data values are returned if they match certain criteria applied to the column for a tagname. For example, if Tagname1 > 5000.

A NULL value indicates that a column entry has no assigned value. A NULL value is not the same as a numeric value of 0 or an empty string.

For value based criteria (narrow tables), data values are returned if they match certain criteria applied to the Value or vValue column. For example, if any possible value > 5000. You can also specify quality criteria for the value.For example, if the data quality for any possible value = Good.

The value based criteria options that are available in the Criteria tab depend upon what types of tags you have selected for the query, either analog, discrete, string, or a mix of these types.

To configure value criteria:

1. To configure criteria for a discrete tag, select the first Value check box and set the criteria to be either a 1 or a 0. Go to Step 5.

2. To configure criteria for an analog or summary tag:

   1. Select the first Value check box and set the criteria for the data value. For example, the value must be greater than ( > ) 1500.

   2. (Optional) Select the second Value check box and set another criteria for the data value. For example, the value must be less than ( < ) 2000.

   3. Go to Step 5.

3. To configure criteria for a string tag:

   1. If you are retrieving history values, select the Use StringHistory check box. In this case, you can only retrieve data for string tags in the query. No data is returned for tags of other types that you may have selected. This is due to a limitation in the AVEVA Historian.

   2. Select the third Value check box and specify text that the returned string value must match. You can specify whether the returned value must equal, start, end, or contain the specified text. For example, you can specify that the value must contain the text "alert."

   3. Go to Step 6.

4. (Optional) Select the Value not null check box to filter out NULL values from the results.

5. (Optional) In the Quality list, click the quality criteria for the data. Only data values that match the quality you specify (Good, Bad, Doubtful) are returned.

6. (Optional) In the OPC Quality list, click the OPC quality criteria for the data. Only data values that match the quality you specify (Good, Bad, Doubtful) are returned.

7. (Optional) In the Criteria applicability list, select the moment at which the edge detection criteria is met.

   • first true: Returns only rows that are the first to successfully meet the criteria (return true) after a row did not successfully meet the criteria (returned false). This is also known as "leading" edge detection.

   • no longer true: Returns only rows that are the first to fail the criteria (return false) after a row successfully met the criteria (returned true). This is also known as "trailing" edge detection.

   • true: Returns all rows that successfully meet the criteria; no edge detection is implemented at the specified resolution.

   • first true or no longer true: All rows satisfying both the leading and trailing conditions are returned.