The basic features in Event Finder allow you to identify all events that meet the search conditions you set. In many situations, you may wish to refine your search conditions. To do so, or to enable more functions in the Event Finder, click , found at the bottom of the Event Finder screen.
Below is a brief description of each of the available functions within the Advanced Options menu.
Important: After configuring or modifying any advanced options, remember to save your query's settings by clicking .
Multiple Search Conditions
By default, when more than one condition is set for your query, the Event Finder will only identify those events that meet all conditions. If you would prefer that the Finder identify those events that meet at least one condition, use the drop-down menu to select the At least one condition has been met option.
Event Start Conditions
By default the Event Finder determines that an event has occurred as soon as the data meets the conditions set in the event definition. By using the Event Start Conditions, you can to set a requirement such that the conditions must be true for at least a fixed period of time before FlowWorks determines that the event has occurred. This can be used to filter-out random spikes in the data set, which would otherwise be identified as an event.
Event End Conditions
By default the Event Finder determines that an event has completed as soon as the data no longer meets the conditions set in the event definition. Similar to the Event Start Conditions, it is possible to set a requirement such that the conditions must be false for at least a specified period of time before an event is considered to be over. This function permits the combining of several small events with intermediate periods where data falls outside of the triggering conditions, into a single large event. This function may also be used to factor-out data spikes that may closely follow the conclusion of a larger event.
The Event Exclusion capability brings great power to the FlowWorks' Event Finder. In addition to excluding events based on duration, you can also filter-out events that occur due to some external condition, such as a low battery or a faulty sensor. Exclusion conditions have the additional option of specifying at what point during the event the condition needs to be met to be included in the results.
In addition to setting exclusion conditions, Event Exclusion option also includes the ability to declare that all execution conditions must be met, or at least one exclusion condition must be met; and whether an exclusion criteria is to be considered when it occurs at the start of an event (such as the tide is above X-feet), during the event, or at the end of the event.
By default, the Event Finder will identify all events that meet the search conditions, and display each event's start date, end date, and duration. You may wish to include additional columns that contains other useful statistics, from the same Site(s) and Channel(s), or even different Site(s) and Channel(s). The channels do not need to be part of your query's original search conditions. This can be useful for determining the impact of the events you've found - for example, an intense storm event, engineers may want to assess the impacts caused by a particular storm event by determining the maximum flow rate recorded during the event.
These additional calculations can be achieved by setting the desired Site(s) and Channel(s) within the Display Statistics option, and specifying the metric(s) you want to include in your query.
Article adapted by David Chapin's original topic, circa 2009.