Use an alarm extension for any point you wish to monitor for offnormal values, and show alarm indication when a limit or value is met or exceeded. In an alarm extension, you also specify whether an alarm annunciation should occur upon alarm transitions, plus many other parameters.
Find the alarm extensions in palettes : (Figure 113) and :.
Alarm extension properties define items such as alarm enable (annunciation) transition types, alarm delay times, associated alarm class, and alarm display text for different transition types. You define the actual alarm limits or state(s) in properties in the extension’s “Offnormal Algorithm” slot. For more details, see About alarm extension properties.
Table 3 lists all alarm extension types and the applicable point parents.
Table 3. Alarm extension types
| Alarm extension type (palette:Folder) | Applies to point types | General description | |
|---|---|---|---|
| (read-only) | Writable | ||
| OutOfRangeAlarmExt (alarm:Extensions) | NumericPoint | NumericWritable | Provides alarming based upon numeric alarm high and low limits. Includes configurable deadband. |
| — | any object with single numeric Out, e.g. kitControl: Math object “Add” | ||
| StringChangeOfValueAlarmExt
(alarm:Extensions)
|
StringPoint | StringWritable | Provides alarming based upon either inclusion or exclusion of the entered string value (or “regular expression”, as needed). |
| — | any object with single String Out, e.g. kitControl: String object “StringSubString” | ||
| BooleanChangeOfStateAlarmExt (alarm:Extensions) | BooleanPoint | BooleanWritable | Provides alarming based upon one of two possible values (state) as an alarm condition. |
| — | any object with single Boolean Out, e.g. kitControl: Logic object “And” | ||
| BooleanCommandFailureAlarmExt (alarm:Extensions) | — | BooleanWritable | Provides alarming based upon mismatch between commanded value and actual (sensed) value. Extension has feedbackValue input property for linking. |
| EnumChangeOfStateAlarmExt (alarm:Extensions) | EnumPoint | EnumWritable | Provides alarming based upon one of multiple possible values (state) as an alarm condition. |
| EnumCommandFailureAlarmExt (alarm:Extensions) | — | EnumWritable | Provides alarming based upon mismatch between commanded value and actual (sensed) value. Extension has feedbackValue input property for linking. |
| StatusAlarmExt (alarm:Extensions) | any type that accepts extensions | any type that accepts extensions | Provides alarming based upon any combination of status flags, including overridden, null, etc. |
| LoopAlarmExt (kitControl:Alarm) | — | LoopPoint | Sliding alarm limit for LoopPoint based upon controlled process deviation from setpoint. |
| ElapsedActiveTimeAlarmExt (kitControl:Alarm) | BooleanPoint with DiscreteTotalizerExt | BooleanWritable with DiscreteTotalizerExt | Provides alarming based upon accumulated runtime (elapsed active time). References a specific DiscreteTotalizerExt under same parent point. |
| — | any object with single Boolean Out (also with a DiscreteTotalizerExt), e.g. kitControl: Logic object “And” | ||
| ChangeOfStateCountAlarmExt (kitControl:Alarm) | BooleanPoint with DiscreteTotalizerExt | BooleanWritable with DiscreteTotalizerExt | Provides alarming based upon accumulated COS (change of states). References a specific DiscreteTotalizerExt under same parent point. |
| — | any object with single Boolean Out (also with a DiscreteTotalizerExt), e.g. kitControl: Logic object “And” | ||
AX-3.6 or later required