Both leading and trailing edge detection for discrete tags

If Both is specified as the parameter in the edge detection extension, all rows satisfying both the leading and trailing conditions are returned.

The following queries select values of "SysPulse" and "MyPulse" that meet an edge detection of Both for a value criterion of 1 (On) from the History and WideHistory tables between 12:59 and 1:04 a.m. on December 8, 2001.

SELECT DateTime, TagName, Value

FROM History

WHERE TagName IN ('SysPulse','MyPulse')

AND DateTime > '2001-12-08 00:59:00'

AND DateTime <= '2001-12-08 01:04:00'

AND Value = 1

AND wwEdgeDetection = 'Both'

The results are:

SELECT DateTime, SysPulse, MyPulse FROM OpenQuery(INSQL, 'SELECT DateTime, SysPulse, MyPulse

FROM WideHistory

WHERE DateTime > "2001-12-08 00:59:00"

AND DateTime <= "2001-12-08 01:04:00"

AND SysPulse = 1

AND MyPulse = 1

AND wwEdgeDetection = "Both"

')

The results are:

Compare these results with the same query using no edge detection, as shown in the Edge detection for discrete tags.