11.8 Threshold configuration using charts

When viewing a chart the user can select the Threshold configuration menu using the [menu] link on the chart. The application shows a form where the user can create simple threshold definitions for every chart member. Not every threshold parameter can be configured this way, only the most important ones, but this mode has a great advantage: before actually creating the threshold the user can investigate and look for the previous time intervals when there would have been an alarm if the threshold would have been created earlier with these parameters. This way the user can make sure that the threshold is created using the proper definition.

The threshold expression can only be a simple one: above a value, below, between or equals/not-equals a value of values (the later in case of an enumeration measurement). When the user selects the operation (greater, smaller, …) from the drop-down list for a chart member then he can also specify the name of the threshold, its level and use the Show button to do the investigation about past measured values.

There are four more buttons on the form:

·       Threshold create: creates the threshold, unless a threshold already exists with the given name

·       Threshold update: the same as the previous one, except that it updates the threshold if it already exists

·       Clear chart: use this to end the investigation

·       Back: close the form

If one of the two first button is used then PVSR shows the created/updated thresholds in a small table above the form and each row in the table has a [view] link which can be used to open the complete threshold definition page for that threshold.