Area Object

The Area AutomationObject represents a physical section of a plant or automation process, or a logical part of an automation application.

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Overview

The Area object is a key member of the core set of AutomationObjects within the ArchestrA system infrastructure. The Area object is classified as a System Object.

An Area represents a production area in a plant or automation process. The primary purpose of an area is to organize all other types of AutomationObjects in a logical manner that mimics the actual physical facility. Areas support hierarchical composition; that is, they support sub-Area construction. Areas can only be nested 10 levels (once the sub-area is 10 levels deep, you cannot add another sub-level).

Areas provide a key organizational role in grouping alarms and events, allowing operators who use alarm/event clients to monitor their areas of responsibility. Areas maintain the alarm and event lists for their assigned ApplicationObjects and provide a mechanisim for client subscriptions to hierarchial organizations of alarms/events through sub-area structures.

For general information on objects, including relationships, deployment, and alarm distribution, see the Integrated Development Environment (IDE) documentation.

For information on configuration options of object scripts, attributes, or features, click Attributes Help in the Help file header.

Run-Time Behavior

The following information describes the run-time behavior of Area objects. Run-time behavior is limited to the state of individual Area objects.

After it has been deployed and is operating, an Area object can assume one of several states, which are described in the following table:


State Change	Behavior
Startup	None.
Going onscan	In this transition state, the data quality of the alarm counters, alarm list, and event list is set to INITIALIZING.
Running onscan	In this state, the Area object: Maintains a list of all the alarm and event messages from the AutomationObjects directly assigned to it. Exceptions are sub-areas, WinPlatforms, AppEngines, and DeviceIntegration Objects (including DeviceIntegration Networks) that are responsible for maintaining their own alarms and events. Updates the alarm and event lists so that subscribed alarm/event clients are notified. Reads the alarm counts from all child areas (or child notification distributors). These values are totaled and included in the alarm total counts. If any of the child areas are offscan, then the data quality of the counter is set to UNCERTAIN. Otherwise, the alarm counter will have quality of GOOD. Sets the data quality for the alarm and event lists to GOOD.
Going offscan	During this transition state, the Area object: Sets the data quality of alarm counters and the alarm list to BAD. Sets the data quality of the event list to GOOD.
Offscan	In this state, the Area object: Maintains only a list of event messages from the assigned AutomationObjects. Updates only the event list in order to notify the subscribed event clients.
Shutdown	The Area object is shut down and performs no role in the system.

Continuous Execution - Alarm Aggregation

With alarm aggregation enabled on the Area object (AlarmAggregationStateCmd value is True), the Area counts all alarms on the area at each scan cycle, and aggregates their status values as follows:

The Area aggregates alarm status information from all alarms on the Area itself, on all Objects and their descendants assigned to the Area, and on all sub-Areas of the Area and their descendants.

The Area aggregates alarm statuses from all child sub-Areas one hierarchical level downward in the model view. The sub-Area aggregation values are added to those of the parent Area. Each sub-Area aggregates alarm statuses from any child sub-Areas one hierarchical level downward. The end result is alarm status information aggregated on the Area itself, on all assigned Objects and their descendants, and on all sub-Areas and their descendants.

The Area checks if the alarm status values aggregated on a sub-Area are more urgent than alarm status values aggregated on the Area itself. If so, the Area updates its own alarm aggregation status values to those of the sub-Area. Otherwise, the Area aggregation status values are unchanged.

The Area adds the sub-Areas’ AlarmCntsBySeverity to its own regardless of relative alarm status urgency.

A sub-Area’s alarm status values can be more urgent than the parent Area’s if:

Pseudo Areas behave like Areas in how they report alarm statuses both in the Distributed Alarm System and in Alarm Aggregation. Pseudo Areas include the WinPlatform Object and Device Integration Objects such as the OPCClient Object and the DDESuiteLinkClient Object. Alarm Aggregation cannot be disabled on pseudo Areas.

Configuration

The following table describes the object editor options for configuration and the associated attributes:

For general information on objects, including relationships, deployment, and alarm distribution, see the Integrated Development Environment (IDE) documentation.

Topic Category	Topic Subcategory	Topic Details
Configuration	General Configuration

For information on configuration options of object scripts, attributes, or features, click Attributes Help in the Help file header.

General Configuration

Use the General tab to configure historization options for Area object alarms.


Editor Option	Associated Attribute	Description	Run-Time Access (Supervisory, User, Read-Only, None)
Historize active alarm counter	AlarmOnCntTotal.Historized	If enabled, the system will historize the total number of active alarms in the Area object, including alarms in sub-areas or sub-notification-distributors.	None
Force storage period	AlarmOnCntTotal.ForceStoragePeriod	See Historization Attributes.	Supervisory, User
Value deadband	AlarmOnCntTotal.ValueDeadBand	See Historization Attributes.	Supervisory, User
Trend High	AlarmOnCntTotal.TrendHi	See Historization Attributes.	Supervisory, User
Trend Low	AlarmOnCntTotal.TrendLo	See Historization Attributes.	Supervisory, User
Interpolation Type	AlarmOnCntTotal.InterpolationType	See Historization Attributes.	Supervisory, User
Sample Count	AlarmOnCntTotal.SampleCount	See Historization Attributes.	Supervisory, User
Rollover Value	AlarmOnCntTotal.RolloverValue	See Historization Attributes.	Supervisory, User
Enable Swinging Door	AlarmOnCntTotal.EnableSwingingDoor	See Historization Attributes.	Supervisory, User
Rate DeadBand	AlarmOnCntTotal.RateDeadBand	See Historization Attributes.	Supervisory, User
Historize unacknowledged alarm counter	AlarmUnAckedCntTotal.Historized	If enabled, the system will historize the total number of unacknowledged alarms and return-to-normals in the Area object, including alarms for sub-areas or sub-notification-distributors.	None
Force storage period	AlarmUnAckedCntTotal.ForceStoragePeriod	See Historization Attributes.	Supervisory, User
Value deadband	AlarmUnAckedCntTotal.ValueDeadBand	See Historization Attributes.	Supervisory, User
Trend High	AlarmUnAckedCntTotal.TrendHi	See Historization Attributes.	Supervisory, User
Trend Low	AlarmUnAckedCntTotal.TrendLo	See Historization Attributes.	Supervisory, User
Interpolation Type	AlarmUnAckedCntTotal.InterpolationType	See Historization Attributes.	Supervisory, User
Sample Count	AlarmUnAckedCntTotal.SampleCount	See Historization Attributes.	Supervisory, User
Rollover Value	AlarmUnAckedCntTotal.RolloverValue	See Historization Attributes.	Supervisory, User
Enable Swinging Door	AlarmUnAckedCntTotal.EnableSwingingDoor	See Historization Attributes.	Supervisory, User
Rate DeadBand	AlarmUnAckedCntTotal.RateDeadBand	See Historization Attributes.	Supervisory, User
Historize disabled (or silenced) alarm counter	AlarmDSCntTotal.Historized	If enabled, the system will historize the total number of disabled and silenced alarms in the object. Sub-areas or sub-notification-distributors are not included.	None
Force storage period	AlarmDSCntTotal.ForceStoragePeriod	See Historization Attributes.	Supervisory, User
Value deadband	AlarmDSCntTotal.ValueDeadBand	See Historization Attributes.	Supervisory, User
Trend High	AlarmDSCntTotal.TrendHi	See Historization Attributes.	Supervisory, User
Trend Low	AlarmDSCntTotal.TrendLo	See Historization Attributes.	Supervisory, User
Interpolation Type	AlarmDSCntTotal.nterpolationType	See Historization Attributes.	Supervisory, User
Sample Count	AlarmDSCntTotal.SampleCount	See Historization Attributes.	Supervisory, User
Rollover Value	AlarmDSCntTotal.RolloverValue	See Historization Attributes.	Supervisory, User
Enable Swinging Door	AlarmOnCntTotal.EnableSwingingDoor	See Historization Attributes.	Supervisory, User
Rate DeadBand	AlarmOnCntTotal.RateDeadBand	See Historization Attributes.	Supervisory, User
Enable Alarm Aggregation	AlarmAggregrationStateCmd	If enabled, the system aggregates alarm status information on all alarms configured in the area object itself, its sub-areas and all child Application objects and their descendants.	None
Enable Shelve Alarms	AlarmShelvingEnableCmd	If enabled, the system permits alarm shelving for any alarm hosted by the Area object, with appropriate user and role permissions.	Read-Only

Run-Time Object Attributes

Note Configurable run-time attributes are described in the configuration sections. For more information, see Configuration.

For a list of common attributes, click Attributes Help in the Help file header.


Attribute	Description	Run-Time Access (Supervisory, User, Read-Only, None)
AlarmDSCnt	The total number of disabled and silenced alarms in the object. Sub-areas or sub-notification-distributors are not included. For extra quality information, see Quality Handling.	Read-Only
AlarmDSCntTotal	The total number of disabled and silenced alarms in the Area object, including alarms in sub-areas or sub-notification-distributors. For extra quality information, see Quality Handling.	Read-Only
AlarmOnCnt	The number of active alarms in the distributor. Does not include sub-areas or sub-notification-distributors. For extra quality information, see Quality Handling.	Read-Only
AlarmOnCntTotal	The total total number of active alarms in the Area object, including alarms in sub-areas or sub-notification-distributors. For extra quality information, see Quality Handling.	Read-Only
AlarmUnAckedCnt	The number of unacknowledged alarms in the distributor (including unacknowledged return-to-normals). Does not include sub-areas or sub-notification-distributors. For extra quality information, see Quality Handling.	Read-Only
AlarmUnAckedCntTotal	The total number of unacknowledged alarms and return-to-normals in the Area object, including alarms for sub-areas or sub-notification-distributors. For extra quality information, see Quality Handling.	Read-Only

Alarm Aggregation Attributes

The following attributes are available for all Objects. If alarm aggregation is enabled on the Area, the following attributes aggregate their respective alarm status values for the Area, for all sub-Areas, contained objects, and their descendants assigned to the Area. If alarm aggregation is disabled, these attributes remain at their default values. Alarm aggregation attributes behave similarly to alarm aggregation of individual attributes.

Topic Category	Topic Subcategory	Topic Details
Alarm Aggregation Attributes	Historization Attributes


Attribute	Description	Run-Time Access (Supervisory, User, Read-Only, None)
<Attribute>.AlarmCntsBySeverity	Array of counts of all alarms that are in UNACK_ALM, ACK_ALM, or UNACK_RTN states on the object, aggregated by severity levels 1-4.	Read-Only
<Attribute>.AlarmMostUrgentAcked	TRUE (default) indicates that no alarms are in the InAlarm state or waiting to be Acked. A value of TRUE also indicates that the most urgent alarm(s) on the object and its descendants in the InAlarm state have been acknowledged, whether or not they are currently InAlarm.	Read-Only
<Attribute>.AlarmMostUrgentIn Alarm	FALSE (default) indicates that no alarms are in the InAlarm state or waiting to be Acked. A value of FALSE indicates whether the most urgent alarm(s) on the object and its descendants are in the InAlarm state, whether or not they have been acknowledged.	Read-Only
<Attribute>.AlarmMostUrgentMode	The AlarmMode of the most urgent alarm(s) on this Object and its descendants. If no alarms are in the InAlarm state or waiting to be Acked, the value is the same as the AlarmMode for the Object.	Read-Only
<Attribute>.AlarmMostUrgent Severity	Severity level expressed as an integer 1-4 of the most urgent alarm(s) on the object and its descendants. If no alarm is in the InAlarm state or waiting to be Acked, the value is 0 (zero).	Read-Only
<Attribute>.AlarmMostUrgent Shelved	The Shelved status as a Boolean value for the “most urgent” alarm(s) on this Object and its descendants. A value of FALSE indicates that no alarms have been Shelved for the "most urgent" alarm(s) on this Object and its descendants.	Read-Only

Historization Attributes

If a historization Feature is enabled, then the following additional history-related attributes become available. None of these attributes can be alarmed.


Attributes	Description
<Attribute>.ForceStoragePeriod	The time interval, in milliseconds, at which the value must be stored, even if the value has not changed. A value of 0 disables this feature. As an example, a setting of 3600000 indicates the value must be stored once per hour (measured from the time the object was last put onscan). If this value is less than the scan period of the host object, forced storage will occur every scan period (effectively equivalent to setting a value deadband of 0).
<Attribute>.TrendHi	The default top of the trend scale for clients. This value must be greater than or equal to the low value for the trend. If this value is changed at run time, the maximum engineering unit change is not reflected in the historian until you redeploy the object. This attribute only applies to numeric data types.
<Attribute>.TrendLo	The default bottom of the trend scale for clients. This value must be less than or equal to the high value for the trend. If this value is changed at run time, the minimum engineering unit change is not reflected in the historian until you redeploy the object. This attribute only applies to numeric data types.
<Attribute>.ValueDeadBand	The amount in engineering units by which a value referenced by the attribute must change to force a storage. A value of 0 means it is unused, and thus any value change forces a storage. Also, a quality change in the attribute always forces a storage regardless of this setting. This attribute only applies to numeric data types.
<Attribute>.Description	The brief description for the attribute that is stored to history. You can use descriptive text or a reference to another string attribute containing the history description. If an attribute reference is used, it must be in the form: "me.AttrName". If you do not provide a description, the object description is used.
<Attribute>.InterpolationType	The method used by the Historian to interpolate analog historical data. The interpolation type determines which analog value is selected during a Historian data retrieval cycle. Interpolation types include System Default, Stairstep, or Linear. The default interpolation type is System Default. For Stairstep, the last known value is returned with the given cycle time. If no valid value can be found, a NULL is returned to the Historian. For Linear, Historian calculates a new value at the given cycle time by interpolating between the last known value prior to the cycle time and the first value after the cycle time. For System Default, the Wonderware Historian system-wide interpolation setting is used. The system-wide setting must be either stairstep or linear interpolated.
<Attribute>.SampleCount	Obsolete. Do not use.
<Attribute>.RolloverValue	A positive integer value that represents a tag’s reset limit when the Historian operates in counter retrieval mode. In counter retrieval mode the Historian uses a tag's rollover value to calculate and return the delta change between consecutive retrieval cycles. The default value is 0.0. The rollover value applies only to numeric attributes. The rollover value is disabled if the historical attribute data type is Boolean or a string.
<Attribute>.EnableSwingingDoor	Enables or disables the swinging door rate deadband. The default is disabled. The swinging door deadband is not applicable to Boolean or string data types. If you provide a valid swinging door rate deadband, the force storage period is now the deadband override period.
<Attribute>.RateDeadBand	The percentage rate of change deadband based on the change in the slope of incoming data values to the Historian. For example, specifying a swinging door rate deadband of 10 percent means that data is saved to the Historian if the percentage change in slope of consecutive data values exceeds 10 percent. The default is 0.0, which indicates a swinging door rate deadband is not applied. Any percentage greater than 0.0 can be assigned to the rate deadband.

Quality Handling

For the following attributes, data quality is set to BAD when the object goes offscan. Also, if any sub-areas or sub-notification distributors are unavailable, the quality is set to BAD.

For the following attributes, if sub-areas are off-scan, data quality will be set to UNCERTAIN. If sub-areas are undeployed, quality will be marked as UNCERTAIN while the undeployed state is verified, after which quality will return to GOOD. Quality is set to BAD when the area itself is placed off-scan.