Enhanced Alarm Configuration
Enhanced Alarm Configuration (EAC) expands the CygNet alarm rules to allow a user to extend the conditions by which a configurable status bit is allowed to be set or prevented from being set. When a configurable bit is prevented from being set, any subsequent alarms or notifications that would have been generated are prevented as well. EAC conditions are defined as a series of logical expressions that reference real-time values of the same point or multiple other points. However, all points referenced must reside in the same Common Value Service (CVS) as the point being configured. EAC conditions may contain up to 50 individual expressions, each of which could reference a separate point. The enhanced alarm configuration is available from the PNT Editor's Alarm Settings (Analog, Digital, Enumeration, String) pages.
Note: All PNT databases must be re-indexed when upgrading CygNet to a version that supports EAC features.
Enhanced Alarm Configuration Rules
The evaluation of EAC conditions that allow or prevent the setting of configurable bits occurs as part of the real-time value processing loop in the CVS. The EAC conditions are executed shortly after the configurable bit thresholds are evaluated to accommodate updates to any referenced points’ real-time values that might be recorded slightly out of sequence.
The rules for Enhanced Alarm Configuration expression are the following:
- Only referenced points residing in the same CVS as the source point are allowed.
- Real-time value updates associated with EAC rules account for the case when source point values arrive before referenced point values. The process attempts to ensure that referenced point values are up-to-date in relation to the source point value, for example, when polling a data group and the processing sequence of the individual DEIDs is not guaranteed to occur in referenced point-values-first order.
- Configuration metrics and errors associated with EAC are reported via PNT and CVS log entries as well as SVCMON info items report metrics, such as the total number of points containing EAC rules and the number of configuration errors. See Shared Service Specific Info Items for more information about CVS_ENHALM_INVPT_CNT, CVS_ENHALM_POINT_CNT and CVS_ENHALM_QUEUE_CNT.
The Point Properties page for the various point types (Analog, Digital, Enumeration, String) includes an Enhanced alarm settings button 
that opens an Enhanced Alarm Settings dialog box for editing.
Other resources
- See Understanding the CVS Metadata File for more information about the elements and attributes that define a CygNet Point Scheme.
- See the following CygNet Blog article: Just say "enhance!" to bring your alarms into crystal-clear focus, which describes a simple demonstration system to help bring some of the EAC concepts to life.
- See the CygNet Studio sample screen, CygNet\Clients\CStudio\Screens\Examples\CopyEacSettings.csf, which can be configured to copy EAC settings between points.
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