An event detector's purpose is to determine if the value of a point satisfies one or more related conditions, and if so, to become "active" and raise an event that can be appropriately handled. A point can have an unlimited number of event detectors. The ways in which events can be detected depend upon the data type of point, and so only the event detectors that apply to the current point's data type are listed in the Type selection.
Event detectors can detect a large number of conditions, but only apply to a single point. If conditions across multiple points or conditions that include scheduled events are required, compound event detectors can be used. See the documentation for compound event detectors.
A point may have as many detectors as necessary, and can have multiple detectors of the same type. (i.e. multiple high limit or low limit detectors.)
To add a new detector select the Type from the list and click the icon. Note that the "Save" button must be clicked to have the detector actually be saved with the point. To delete an existing detector click the
icon associated with the detector.
Each detector type has an Alarm level attribute. This determines whether the detector raises an alarm when active, and if so the severity of the alarm. See the general help page for information on Alarms.
This detector applies only to Numeric points. The High limit is the value above which the detector becomes active. The detector may optionally be configured with a Duration; the point's value must stay above the high limit for at least the given duration before the detector becomes active. Events raised by this detector will automatically return to normal when the condition is no longer satisfied.
This detector applies only to Numeric points. The Low limit is the value below which the detector becomes active. The detector may optionally be configured with a Duration; the point's value must stay below the low limit for at least the given duration before the detector becomes active. Events raised by this detector will automatically return to normal when the condition is no longer satisfied.
This detector applies to all data types. It raises an event whenever the point value changes. Events raised by this detector do not automatically return to normal.
This detector applies to all data types. It raises an event whenever the value has not changed within the given Duration. This can be useful to detect when equipment is malfunctioning. Events raised by this detector will automatically return to normal when the condition is no longer satisfied.
This detector applies to all data types. It raises an event whenever the value has not been updated within the given Duration. (A point value change requires the new point value to be different from the previous point value. A point value update only requires the time of the point value to change; the value itself can remain the same.) This can be useful to detect when equipment is malfunctioning. Events raised by this detector will automatically return to normal when the condition is no longer satisfied.
This detector applies to Binary, Multistate, and Alphanumeric points. It becomes active whenever the point enters the given State. The detector may optionally be configured with a Duration; the point must stay in the given state for at least the given duration before the detector becomes active. Events raised by this detector will automatically return to normal when the condition is no longer satisfied.
This detector applies only to Binary, Multistate, and Alphanumeric points. It becomes active whenever the point value changes at least Change count times within the given Duration. Events raised by this detector will automatically return to normal when the condition is no longer satisfied.