User Defined Object

The User Defined object provides the basic functionality you need to develop an ArchestrA supervisory application. The User Defined object provides this functionality as Features, Attributes, scripts, and graphics.

This help file contains information specific to the User Defined Object. For information on configuration options for Attributes, scripts, and graphics, click the appropriate link in the header of this help file.

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

Click one of the following topics to navigate to information about that topic.

Topic Category
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Defining Discrete Attribute Options

Using the User Defined Object

The User Defined object is a shell object that you can use to create custom objects. You can use the User Defined object in the following ways:

  1. As a template containing Attributes associated to multiple variables in a system.

In this case, the object provides a simple and manageable structure as all the variables are contained in the same object.

For example, you might create a User Defined object called "Tank" and configure Attributes that represent variables associated to the tank system:

References between attributes in the object can be accomplished by using relative references, for example:

The "Tank" can be customized to raise an alarm when both XV100a and XV100b valves are open. For example, you can add a Boolean Attribute called "ValueOpenAlarm", configure it with an Alarm Feature, and then add the following OnExecute script:

IF me.XV100a == "Open" AND me.XV100b == "Open" THEN

me.ValueOpenAlarm = true;

ELSE

me.ValueOpenAlarm = false;

ENDIF;

  1. As a "container" for other objects.

An object relationship in which one object is comprised of other objects is called containment. Containment allows you to group various objects together to make complex objects.

For detailed information on object containment, see the Wonderware Application Server User Guide, Integrated Development Environment (IDE) documentation.

Working with Legacy Attributes

As of Application Server 2014 R2, Field Attribute functionality has been combined into a single, unified attribute which you can create and configure using the Attributes page available in all object editors.

By default, the Field Attributes tab will be displayed for an object only if the object has existing Field Attributes. You can override the default by enabling the Show Field Attributes tab option.

  1. Click Edit on the IDE main menu, then click User Information. The Configure User Information dialog box appears.
  2. Select Show the Field Attributes tab to display the Field Attributes tab in the User Defined Object editor.

Related Topics

Configuring Field Attributes

Use the Field Attributes tab to configure Discrete and Analog Field Attributes. To add an attribute, you must select the Discrete or Analog icon button.

Related Topics

Defining Discrete Attribute Options

Defining Discrete Attribute Options

The following properties are part of the Discrete Field Attribute:

Editor Option
Description
Name
The name property of the Field Attribute.
Attribute type
The type property of the Field Attribute.
Category
The attribute category property of the Field Attribute.
Initial state
The initial state of the Field Attribute.
 
If the Field Attribute is configured as Output, the Field Attribute value is set to FALSE.
 
If the Field Attribute is configured as Input or InputOutput, the Field Attribute value is determined by the state of the input value.

Note A Field Attribute that starts with an underscore as the first character of the Field Attribute name is defined as a hidden attribute. Hidden attributes do not appear in Attribute Browser, Object Viewer, or the Attributes tab from the Properties box. Object Viewer and the Attributes tab from the Properites box provides the option to view hidden attributes. To show hidden attributes, go to the Galaxy menu, click Properties, select the Attributes tab, and select Include hidden.

The following options are available for a Discrete attribute:

Editor Option
Associated Attribute
Description
Run-Time Access (Supervisory, User, Read-Only, None)
Access mode
AccessMode
The read/write capabilities for the object. Valid values are Input, InputOutput, and Output.
None
Description
Desc
By default, the Field Attribute description is used for alarm and event comments, as well as historization. If you configure a description for the history extension, this description is used instead. String limit to 256 characters.
Read-Only
Invert
InvertValue
If enabled, the Field Attribute value is inverted when reading from the input source and when writing to the output destination.
Read-Only
Generate event upon value change
LogDataChangeEvent
If enabled, data change events for the Field Attribute will be logged to event history.
Supervisory, User

Related Topics

Input/Output Attributes

The following Input/Output attributes are available for a Discrete attribute:

Editor Option
Associated Attribute
Description
Run-Time Access (Supervisory, User, Read-Only, None)
Input source
Input.InputSource
The target source from which the value is to be read. Click the ellipse button to access the Attribute Browser.
Supervisory, User
Output destination differs from input source
Output.DiffAddr
If enabled, the output destination can be configured to be different than the input source.
None
Output destination
Output.OutputDest
The target location to which the output value will be written. Click the ellipse button to access the Attribute Browser.
Supervisory, User

There is a difference between InputOutput extension and Field Attribute when setting InputSource and OutputDest via a script.

InputOutput extension: me.UDA.InputSource = "ABPLC5.B13:0/0"

Field Attribute: me.FieldAttr.Input.InputSource = "ABPLC5.B13:0/0"

me.UDA.InputSource = "ABPLC5.B13:0/0"

me.FieldAttr.Input.InputSource = "ABPLC5.B13:0/0"

me.FieldAttr.Output.OutputDest = "ABPLC5.B13:0/0"

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State Labels Attributes

If Enable state labels is enabled, then the following attributes become available.

Editor Option
Associated Attribute
Description
Run-Time Access (Supervisory, User, Read-Only, None)
Enable state labels
UseOffOnMsg
If enabled, the state labels will appear in history, alarms, and events.
None
Label for ’False’ state
OffMsg
The state label appears in the "Msg" attribute when the value is FALSE.
Read-Only
Label for ’True’ state
OnMsg
The state label appears in the "Msg" attribute when the value is TRUE.
Read-Only

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Discrete History Attributes

If Enable history is enabled, then the following additional history-related attributes become available.

Editor Option
Associated Attribute
Description
Run-Time Access (Supervisory, User, Read-Only, None)
Enable history
Historized
If enabled, the system will historize the Field Attribute value.
None
Force storage period
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).
Supervisory, User
Sample count
SampleCount
Obsolete. Do not use.
Supervisory, User

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State Alarm Attributes

If Enable state alarm is enabled, then the following additional discrete alarm-related attributes become available.

Editor Option
Associated Attribute
Description
Run-Time Access (Supervisory, User, Read-Only, None)
Enable state alarm
Alarmed
If enabled, the alarm will be triggered based on the Discrete Field Attribute state.
None
Active alarm state
ActiveAlarmState
The state of the Discrete Field Attribute when the state alarm is triggered.
Supervisory, User
Alarm message
DescAttrName
See Alarm Attributes. Click the ellipse button to access the Attribute Browser.
Supervisory, User
Priority
Priority
Supervisory, User
Time deadband
BooleanAlarm.TimeDeadband
The time, in seconds, that must elapse after the Field Attribute value exceeds an alarm limit before the alarm is triggered.
Supervisory, User
Category
Category
The alarm category.
Supervisory, User

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Bad Value Alarm Attributes

If Enable bad value alarm is enabled, then the following additional bad value alarm-related attributes become available.

Editor Option
Associated Attribute
Description
Run-Time Access (Supervisory, User, Read-Only, None)
Enable bad value alarm
Bad.Alarmed
If enabled, alarms will be triggered when the Field Attribute has bad data values or bad data quality.
None
Alarm message
Bad.DescAttrName
See Alarm Attributes. Click the ellipse button to access the Attribute Browser.
Supervisory, User
Priority
Bad.Priority
Supervisory, User

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Discrete Statistics Attributes

If Enable statistics is enabled, then the following additional statistics-related attributes become available.

Editor Option
Associated Attribute
Description
Run-Time Access (Supervisory, User, Read-Only, None)
Enable statistics
HasStatistics
If enabled, statistics will be calculated for the Discrete attribute.
None
Auto-reset on bad value
Stats.AutoResetOnBadInput
If enabled, the input automatically triggers a reset command when the quality of an input goes from BAD or UNCERTAIN to GOOD.
Supervisory, User
Statistics reset
Stats.Reset
Resets the following run-time attributes:
  • State0Cnt
  • State1Cnt
  • State0Duration
  • State1Duration
  • State0Time
  • State1Time
 
Sets the previous values of the resettable run-time attributes to their corresponding Last attribute.
 
Sets the elapsed times of the TimeSinceLastTransition to 00:00:00:000.
Supervisory, User

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Defining Analog Attribute Options

The following properties are part of the Analog Field Attribute:

Editor Option
Description
Name
The name property of the Field Attribute.
Attribute Type
The type property of the Field Attribute.
Category
The attribute category property of the Field Attribute.
Value
If the Field Attribute is configured as Output, then Value is the initial Field Attribute value.
 
If the Field Attribute is configured as Input or InputOutput, the Field Attribute value is determined by the input value.

Note A Field Attribute that starts with an underscore as the first character of the Field Attribute name is defined as a hidden attribute. Hidden attributes do not appear in Attribute Browser, Object Viewer, or the Attributes tab from the Properties box. Object Viewer and the Attributes tab from the Properites box provides the option to view hidden attributes. To show hidden attributes, go to the Galaxy menu, click Properties, select the Attributes tab, and select Include hidden.

The following user options are available for an Analog attribute:

Editor Option
Associated Attribute
Description
Run-Time Access (Supervisory, User, Read-Only, None)
Access mode
AccessMode
The read/write capabilities for the object. Valid values are Input, InputOutput, and Output.
None
Data type
AnalogType
The data type, Double, Float, Integer, of the analog attribute.
None
Description
Desc
By default, the Field Attribute description is used for alarm and event comments, as well as historization. If you configure a description for the history extension, this description is used instead. String limit to 256 characters.
Read-Only
Generate event upon value change
LogDataChangeEvent
If enabled, data change events for the Field Attribute will be logged to event history.
Supervisory, User
Value deadband
Deadband
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.
Supervisory, User
Engineering units
EngUnits
The name of the engineering units. For example, PSI. The maximum number of characters is 32.
Read-Only

Related Topics

Input/Output Attributes

The following Input/Output attributes are available.

Editor Option
Associated Attribute
Description
Run-Time Access (Supervisory, User, Read-Only, None)
Input source
Input.InputSource
The target source from which the value is to be read. Click the ellipse button to access the Attribute Browser.
Supervisory, User
Output destination differs from input source
Output.DiffAddr

If enabled, the output destination can be configured to be different than the input source.

 

None
Output destination
Output.OutputDest

The target location to which the output value will be written.

Click the ellipse button to access the Attribute Browser.

Supervisory, User

There is a difference between InputOutput extension and Field Attribute when setting InputSource and OutputDest via a script.

InputOutput extension: me.UDA.InputSource = "ABPLC5.N7:2"

Field Attribute: me.FieldAttr.INPUT.InputSource = "ABPLC5.N7:2"

me.UDA.InputSource = "ABPLC5.N7:2"

me.FieldAttr.INPUT.InputSource = "ABPLC5.N7:2"

me.FieldAttr.OUTPUT.OutputDest = "ABPLC5.N7:2"

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Scaling Attributes

If Enable I/O scaling is enabled, then the following additional scaling alarm-related attributes become available.

Editor Option
Associated Attribute
Description
Run-Time Access (Supervisory, User, Read-Only, None)
Enable I/O scaling
Scaled
Used to enable scaling between the raw value and the EU value.
None
Raw value - Minimum
RawMin
The raw input minimum to be used in the scaling calculation.
Supervisory, User
Raw value - Maximum
RawMax
The raw input maximum to be used in the scaling calculation.
Supervisory, User
EU value - Minimum
EngUnitsMin
The minimum value, in engineering units, used in the scaling calculation.
Supervisory, User
EU value - Maximum
EngUnitsMax
The maximum value, in engineering units, used in the scaling calculation.
Supervisory, User
EU range value - Minimum
EngUnitsRangeMin
The lowest allowed value for the Field Attribute before it is either clamped or set NaN, if clamping is enabled. This value must be less than or equal to the specified minimum engineering unit value.
 
If Square root conversion is enabled, EngUnitsRangeMin is not configurable and is set equal to the EngUnitsMin attribute.
Supervisory, User
EU range value - Maximum
EngUnitsRangeMax
The highest allowed value for the Field Attribute before it is either clamped or set NaN, if clamping is enabled. This value must be greater than or equal to the specified maximum engineering unit value.
 
If Square root conversion is selected, EngUnitsRangeMax is not configurable and is set equal to EngUnitsMax attribute.
Supervisory, User
Conversion mode
ConversionMode
Used to specify either Linear or Square root for the equation that will be used to scale the input
 
If Square root is selected, the raw value is clamped to the MinRaw and MaxRaw value range before the Square root conversion is executed.
 
The Quality will be set to the following: BAD quality if the raw value has BAD quality, to INITIALIZING quality if the raw value has INITIALIZING quality, and to GOOD quality otherwise.
Read-Only
Clamp input to EU range
ClampEnabled
Used to allow the scaling process to clamp the engineering unit result.
 
If clamping is enabled, the scaling calculation result is clamped at either the maximum engineering unit range value or the minimum engineering unit range value, and the Field Attribute quality is set to UNCERTAIN.
 
If not clamped, and the Field Attribute value exceeds the engineering unit range, then the value will continue to scale out of range, and the quality is set to BAD.
 
If Square root conversion is selected, ClampEnabled is not configurable.
Supervisory, User

Related TopicsRelated Topics

Analog History Attributes

If Enable history is enabled, then the following additional history-related attributes become available.

Editor Option
Associated Attribute
Description
Run-Time Access (Supervisory, User, Read-Only, None)
Enable history
Historized
If enabled, the system will historize the Field Attribute value.
None
Force storage period
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).

 
Supervisory, User
Value deadband
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.

 
Supervisory, User
Trend high
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.

 
Supervisory, User
Trend low
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.

 
Supervisory, User
Interpolation Type
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.

 
Supervisory, User
Sample Count
SampleCount
Obsolete. Do not use.
Supervisory, User
Rollover Value
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.

 
Supervisory, User
Enable Swinging Door
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.

 
 
Rate DeadBand
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.

 
Supervisory, User

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Limit Alarms Attributes

If Enable limit alarms is enabled, then the following additional limit alarm-related attributes become available.

Editor Option
Associated Attribute
Description
Run-Time Access (Supervisory, User, Read-Only, None)
Enable limit alarms
LimitAlarmed
If enabled, alarms will be triggered when the value reaches configured alarm limits.
None
HiHi
HiHi.Alarmed
If enabled, an alarm will be triggered when the Field Attribute value reaches the HiHi limit.
None
HiHi - Limit
HiHi.Limit
The HiHi limit that the Field Attribute value must exceed to trigger an alarm.
Supervisory, User
HiHi - Priority
HiHi.Priority
Supervisory, User
HiHi - Alarm message
HiHi.DescAttrName
See Alarm Attributes. Click the ellipse button to access the Attribute Browser.
Supervisory, User
Hi
Hi.Alarmed
If enabled, an alarm will be triggered when the Field Attribute value reaches the Hi limit.
None
Hi - Limit
Hi.Limit
The Hi limit that the Field Attribute value must exceed to trigger an alarm.
Supervisory, User
Hi - Priority
Hi.Priority
Supervisory, User
Hi - Alarm message
Hi.DescAttrName
See Alarm Attributes. Click the ellipse button to access the Attribute Browser.
Supervisory, User
Lo
Lo.Alarmed
If enabled, an alarm will be triggered when the Field Attribute value reaches the Lo limit.
None
Lo - Limit
Lo.Limit
The Lo limit that the Field Attribute value must exceed to trigger an alarm.
Supervisory, User
Lo - Priority
Lo.Priority
Supervisory, User
Lo - Alarm message
Lo.DescAttrName
See Alarm Attributes. Click the ellipse button to access the Attribute Browser.
Supervisory, User
LoLo
LoLo.Alarmed
If enabled, an alarm will be triggered when the Field Attribute value reaches the LoLo limit.
None
LoLo - Limit
LoLo.Limit
The LoLo limit that the Field Attribute must exceed to trigger an alarm.
Supervisory, User
LoLo - Priority
LoLo.Priority
Supervisory, User
LoLo - Alarm message
LoLo.DescAttrName
See Alarm Attributes. Click the ellipse button to access the Attribute Browser.
Supervisory, User
Alarm deadband
LimitAlarm.ValueDeadband
The amount, in engineering units, that the Field Attribute value must drop below either the HiHi limit or Hi limit, or increase above either the LoLo limit or Lo limit before an alarm is triggered.
Supervisory, User
Time deadband
LimitAlarm.TimeDeadband
The time, in seconds, that must elapse after the Field Attribute value exceeds an alarm limit before the alarm is triggered.
Supervisory, User

Related TopicsRelated Topics

Rate of Change Alarm Attributes

If Enable rate of change alarms is enabled, then the following additional scaling alarm-related attributes become available.

Editor Option
Associated Attribute
Description
Run-Time Access (Supervisory, User, Read-Only, None)
Enable rate of change alarms
ROCAlarmed
If enabled, alarms will be triggered for when the Field Attribute level reaches configured rates of change.
None
Up
ROC.IncreasingHi.Alarmed
If enabled, an alarm will be triggered when the Field Attribute value is increasing too fast.
None
Up - Limit
ROC.IncreasingHi.Limit
The alarm limit that the rate of change calculation must exceed in order to trigger an alarm.
Supervisory, User
Up - Priority
ROC.IncreasingHi.Priority
Supervisory, User
Up - Alarm message
ROC.IncreasingHi.DescAttrName
See Alarm Attributes. Click the ellipse button to access the Attribute Browser.
Supervisory, User
Down
ROC.DecreasingHi.Alarmed
If enabled, an alarm will be triggered when the Field Attribute value is decreasing too fast.
None
Down - Limit
ROC.DecreasingHi.Limit
The alarm limit that the rate of change calculation must exceed in order to trigger an alarm. (This value, although a positive value, actually indicates a negative rate of change, or a descending rate of change Hi limit.)
Supervisory, User
Down - Priority
ROC.DecreasingHi.Priority
Supervisory, User
Down - Alarm message
ROC.DecreasingHi.DescAttrName
See Alarm Attributes. Click the ellipse button to access the Attribute Browser.
Supervisory, User
Changes per
ROC.Rate.Units
The units of time for the rate of change calculation.
Supervisory, User
Evaluate every
ROC.EvalPeriod
The time interval, in milliseconds, at which the rate of change calculation and detection is performed.
None

Related TopicsRelated Topics

Target Deviation Alarm Attributes

If Enable target deviation alarms is enabled, then the following additional scaling alarm-related attributes become available.

Editor Option
Associated Attribute
Description
Run-Time Access (Supervisory, User, Read-Only, None)
Enable target deviation alarms
DeviationAlarmed
If enabled, alarms will be triggered for when the Field Attribute level deviates from a target value by a configured amount.
None
Minor
Dev.Minor.Alarmed
If enabled, an alarm will be triggered when the Field Attribute value reaches the minor deviation tolerance.
None
Minor - Tolerance
Dev.Minor.Tolerance
The minor deviation tolerance that the Field Attribute value must exceed to trigger an alarm.
Supervisory, User
Minor - Priority
Dev.Minor.Priority
Supervisory, User
Minor - Alarm message
Dev.Minor.DescAttrName
See Alarm Attributes. Click the ellipse button to access the Attribute Browser.
Supervisory, User
Major
Dev.Major.Alarmed
If enabled, an alarm will be triggered when the Field Attribute value reaches the major deviation tolerance.
None
Major - Tolerance
Dev.Major.Tolerance
The major deviation tolerance that the Field Attribute value must exceed to trigger an alarm.
Supervisory, User
Major - Priority
Dev.Major.Priority
Supervisory, User
Major - Alarm message
Dev.Major.DescAttrName
See Alarm Attributes. Click the ellipse button to access the Attribute Browser.
Supervisory, User
Target
Dev.Target
Sets the Field Attribute target setpoint value for deviation calculation.
Supervisory, User
Deviation deadband
Dev.Deadband
The amount the Field Attribute value must drop (measured in engineering units) below any of the deviation limits before the respective condition is set to FALSE.
Supervisory, User
Settling period
Dev.SettlingPeriod
The time, in seconds, allowed for the Field Attribute value to return within allowable range after a Target change is made before the deviation alarm is triggered. (A deviation alarm cannot occur again until the alarm clears.) The value you specify will be converted to the following format: days hh:mm:ss.fffffff.
Supervisory, User

Related TopicsRelated Topics

Bad Value Alarm Attributes

If Enable bad value alarm is enabled, then the following additional bad value alarm-related attributes become available.

Editor Option
Associated Attribute
Description
Run-Time Access (Supervisory, User, Read-Only, None)
Enable bad value alarm
Bad.Alarmed
If enabled, alarms will be triggered when the Field Attribute has bad data value or data quality.
None
Alarm message
Bad.DescAttrName
See Alarm Attributes. Click the ellipse button to access the Attribute Browser.
Supervisory, User
Priority
Bad.Priority
Supervisory, User

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Analog Statistics Attributes

If Enable statistics is enabled, then the following additional statistics-related attributes become available.

Editor Option
Associated Attribute
Description
Run-Time Access (Supervisory, User, Read-Only, None)
Enable statistics
HasStatistics
If enabled, statistics will be calculated for the Analog Field Attribute.
None
Auto-reset on bad value
Stats.AutoResetOnBadInput
If enabled, the input automatically triggers a reset command when the quality of an input goes from BAD or UNCERTAIN to GOOD.
Supervisory, User
Values per sample set
Stats.SampleSize
The maximum number of samples to collect in calculating the mean and standard deviation. The minimum number of samples is 2.
 
Note: A large sample set will impact performance at run-time.
Supervisory, User
Statistics reset
Stats.Reset
Resets the following run-time attributes:
  • Min
  • Max
  • SampleSetMin
  • SampleSetMax
  • Average
Supervisory, User

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Field Attributes Run-Time Behavior

The following information describes the run-time behavior of Discrete and Analog Field Attributes.

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Discrete Attributes Run-Time Behavior

After a User Defined object is deployed and operating, Discrete Field Attributes can assume one of the following states:

State
Behavior
Startup
  • If the Field Attribute has only an output, the initial Field Attribute value will be used as the initial value.
  • If the Field Attribute has only an output, the time stamp of the data value is set to the current time.
  • If the Access mode is Input or InputOutput, the value of the Value attribute is set to the default value for the attribute data type, the time stamp is set to the current time, and the quality is set to BAD.
Going onscan
  • If the AccessMode is Input or InputOutput, then the Field Attribute value quality is set to INITIALIZING.
  • If the AccessMode is Output, the Field Attribute value is set to the initial state value and the value quality is set to GOOD.
  • If the Access mode is Input or InputOutput, the time stamp of the Value attribute is set to the current time.
Execute
  • If the AccessMode is Input or InputOutput, read the new input value and quality and set it into the Field Attribute value.
  • If a new Field Attribute value output is requested, and the AccessMode is InputOutput or Output, the requested new Field Attribute value is written to the output location.
  • Detect state alarms, if configured.
  • Detect bad value alarm, if configured.
Going offscan
  • If the AccessMode is Input or InputOutput, the Field Attribute value quality is set to BAD and all alarm conditions are set to FALSE.
  • If the AccessMode is Output, the Field Attribute value and quality is set to the last written value. The time stamp is retained.
  • If the Access mode is Input or InputOutput, the time stamp of the Value attribute is set to the current time if the quality changes because of a scan state change.
Offscan
The object is passive.
Shutdown
If references to field attributes were registered and suspended at startup, the references are activated and unregistered.

Related Topics

Discrete Attribute Run-time Behavior - General

Input processing (when Input is configured)

Statistics processing (when Statistics are enabled)

Alarm processing

Related Topics

Discrete Attribute Run-time Behavior - Alarms

The time stamp for when the alarm becomes active or inactive is the most recent time stamp of the corresponding input value, if any; if there is no time stamp, the AppEngine scan time is used.

When alarms are enabled, you can set an individual limit, deviation, ROC, or state alarm to be enabled, silenced, or disabled. This setting only applies to the individual alarm. No other alarm settings for the object are affected, and the setting is not propagated to contained objects.

The actual behavior is based upon the most restrictive enable/silence/disable AlarmMode in the object hierarchy.

When alarms are enabled, you can set an individual alarm to be inhibited. The inhibition setting applies only to an individual alarm. No other alarm settings for the object are affected, and the setting is not propagated to contained objects. If alarms are not inhibited, the alarm behavior is determined by the AlarmMode setting.

Related Topics

Discrete Attribute Run-time Behavior - Alarm Aggregation on Attributes

Alarm Aggregation on individual Attributes are summarized by the alarm aggregation attributes, updated at each scan cycle, and are displayed at run time.

All Objects, including the User Defined Object, support Alarm Aggregation for all alarms on the entire Object, alarms on all contained Objects, and their descendants.

Individual Attributes support Alarm Aggregation on the attribute itself. An Attribute can have multiple alarms configured on it, all of which are summarized for each Attribute, and all of which are included in the Alarm Aggregation for the entire Object.

Related Topics

Discrete Attribute Run-time Behavior - Statistics

The following describes the Discrete statistics run-time behavior:

Note Enabling Discrete statistics increases system resources utilization due to the checkpointing of all calculated statistical values. Since a majority of these calculations are updated on every execution cycle of the engine, they are checkpointed on every execution cycle.

When calculating TimeSinceLastTransition:

On failover:

Related Topics

Discrete Attribute Run-time Behavior - Advisement of Active Items

If you configure the object to have input or input/output and advisement of active items is enabled globally, both the reference count and suspend count for the field attributes are incremented when the object starts up. This puts the object into a suspended state and propagates a suspend message to the input sources.

When the object is in a suspended state, no input scanning occurs, because no new input values are being sent by the input source. The quality of the suspended attribute is INITIALIZING.

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Discrete Attribute Run-time Behavior - Time Propagation

If you configure the access mode as Input or InputOutput, the field attribute’s time stamp always reflects the time stamp of the input.

If you configure the access mode as Output or InputOutput, the time stamp provided by the value or time set request is forwarded to the output. The value is based on the field attribute's existing value.

If you configure the access mode as Output, the timestamp provided by the value set request is used to update the field attribute if it is not zero. Otherwise, the current time is used.

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Analog Attributes Run-Time Behavior

The following information describes the run-time behavior of User Defined analog Field Attributes.

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Analog Attribute State Changes

After a User Defined object is deployed and operating, Analog Field Attributes can assume one of the following states:

State
Behavior
Startup
  • If the Access mode is Input or InputOutput, the value of the Value attribute is set to the default value for the attribute data type, the time stamp is set to the current time, and the quality is set to BAD.
  • If the Field Attribute has only an output, the time stamp of the data value is set to the current time.
Going onscan
  • If the Access mode is Input or InputOutput, then the Field Attribute value quality is set to INITIALIZING.
  • If the Access mode is Output, the Field Attribute value is set to the initial state value and the value quality is set to GOOD.
  • If the Access mode is Input or InputOutput, the time stamp of the Value attribute is set to the current time.
Execute
  • If the Access mode is Input or InputOutput, read the new input value and quality and set it into the Field Attribute value.
  • If a new Field Attribute value output is requested, and the Access mode is InputOutput or Output, the requested new Field Attribute value is written to the output location.
  • Detect limit alarms, rate of change alarms, target deviation alarms and bad value alarms, if configured.
Going offscan
  • If the Access mode is Input or InputOutput, the Field Attribute value quality is set to BAD and all alarm conditions are set to FALSE.
  • If the Access mode is Output, the Field Attribute value and quality is set to the last written value. The time stamp is retained.
  • If the Access mode is Input or InputOutput, the time stamp of the Value attribute is set to the current time if the quality changes because of a scan state change.
Offscan
The object is passive.
Shutdown
If references to field attributes were registered and suspended at startup, the references are activated and unregistered.

Related Topics

Analog Attribute Run-time Behavior - General

Input processing

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Analog Attribute Run-time Behavior - Alarms

The time stamp for when the alarm becomes active or inactive is the most recent time stamp of the corresponding input value, if any; if there is no time stamp, the AppEngine scan time is used.

When alarms are enabled, you can set an individual limit, deviation, ROC, or state alarm to be enabled, silenced, or disabled. This setting only applies to the individual alarm. No other alarm settings for the object are affected, and the setting is not propagated to contained objects.

The actual behavior is based upon the most restrictive enable/silence/disable AlarmMode in the object hierarchy.

When alarms are enabled, you can set an individual alarm to be inhibited. The inhibition setting applies only to an individual alarm. No other alarm settings for the object are affected, and the setting is not propagated to contained objects. If alarms are not inhibited, the alarm behavior is determined by the AlarmMode setting.

Limit Alarms

Generic limit checking done for all high limit alarms are:

Generic limit checking for low limit alarms:

Deviation Alarms

When the Field Attribute is set to NaN, the following occurs:

Limit checking for each deviation is as follows:

Rate of Change (ROC) Alarms

When the Field Attribute is set to NaN, the following occurs:

Limit checking for each ROC alarm is as follows.

ROC alarms are used to detect and report a condition when the Field Attribute value increases or decreases at too fast of a rate. You can specify a limit for both the increasing and decreasing directions. For the increasing limit, if the Field Attribute value increases at a rate greater than the limit, an alarm is generated. Similarly, for the decreasing limit, if the Field Attribute value decreases at a rate greater than the limit, an alarm is generated. The limit value in either case is a positive number.

In addition to specifying the rate limit value, the time dimension for the rate must be specified depending on the time dynamics of the variable being measured. The choices are per second, per minute, per hour, and per day. For calculation of the rate itself, the time interval at which the rate (or slope between points) is calculated is also specified as a time interval in milliseconds.

For example, if you want to put a rate limit on the rate at which a number of gallons accumulates in a tank at 200 gallons per minute, and you want to specify the calculation to be performed every 5 seconds, then specify:

IncreasingHi.Limit = 200

Rate.Units = Min

EvalPeriod = 5000

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Analog Attribute Run-time Behavior - Alarm Aggregation on Attributes

Alarm Aggregation on individual Attributes are summarized by the alarm aggregation attributes, updated at each scan cycle, and are displayed at run time.

All Objects, including the User Defined Object, support Alarm Aggregation for all alarms on the entire Object, alarms on all contained Objects, and their descendants.

Individual Attributes support Alarm Aggregation on the attribute itself. An Attribute can have multiple alarms configured on it, all of which are summarized for each Attribute, and all of which are included in the Alarm Aggregation for the entire Object.

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Analog Attribute Run-time Behavior - Scaling

When the Field Attribute is set to NaN, the scaling attribute is not calculated and the quality of the scaling value will remain GOOD.

For linear scaling, the following equation is used:

For square root scaling, the following equation is used:

On failover, all calculated scaling values are maintained and the quality is set to UNCERTAIN.

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Analog Attribute Run-time Behavior - Statistics

When the Analog Field Attribute is set to NaN, all calculated statistic attributes quality is set to "UNCERTAIN" and the calculations continue based on the last value of GOOD quality.

Note Enabling Analog statistics increases system resources utilization due to the checkpointing of all calculated statistical values. Since a majority of these calculations are updated on every execution cycle of the engine, they are checkpointed on every execution cycle.

For calculating average, the following equation is used:

For calculating standard deviation, the following equation is used:

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Analog Attribute Run-time Behavior - Redundancy

On failover, all calculated statistic values quality is set to UNCERTAIN. The following Analog Field Attribute values will be retained:

After a failover, the Min and Max values will only update when the quality of a new Field Attribute value is GOOD or UNCERTAIN that is less than the existing Min or greater than the existing Max is reached. The new value quality will replace the existing value quality.

After a failover, the SampleSetMin and SampleSetMax values will only update when a new Field Attribute value is GOOD or UNCERTAIN that is less than the existing Min or greater than the existing Max is reached.

When the SampleSet is updated with new value qualities of GOOD or UNCERTAIN, the SampleSetMin and SampleSetMax will be set based on the Minimum and Maximum values in the sample set.

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Analog Attribute Run-time Behavior - Advisement of Active Items

If you configure the object to have input or input/output and advisement of active items is enabled globally, both the reference count and suspend count for the field attributes are incremented when the object starts up. This puts the object into a suspended state and propagates a suspend message to the input sources.

When the object is in a suspended state, no input scanning occurs, because no new input values are being sent by the input source. The quality of the suspended attribute is INITIALIZING.

Related Topics

Analog Attribute Run-time Behavior - Time Propagation

If you configure the access mode as Input or InputOutput, the field attribute’s time stamp always reflects the time stamp of the input.

If you configure the access mode as Output or InputOutput, the time stamp provided by the value or time set request is forwarded to the output. The value is based on the field attribute's existing value.

If you configure the access mode as Output, the timestamp provided by the value set request is used to update the field attribute if it is not zero. Otherwise, the current time is used.

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Run-Time Object Attributes

The following tables describe the run-time only attributes for the object.

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

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Discrete Run-Time Object Attributes

Attribute
Description
Run-Time Access (Supervisory, User, Read-Only, None)
AlarmCntsBySeverity
Array of counts of all alarms that are in UNACK_ALM, ACK_ALM, or UNACK_RTN states on the attribute, aggregated by severity levels 1-4.
Read-Only
AlarmMostUrgentAcked
TRUE (default) indicates that no alarms are in the InAlarm state or waiting to be Acked. A value of TRUE can also indicate that the most urgent alarm(s) on the attribute in the InAlarm state have been acknowledged, whether or not they are currently InAlarm.
Read-Only
AlarmMostUrgentInAlarm
FALSE (default) indicates that no alarms are in the InAlarm state or waiting to be Acked.
A value of FALSE also indicates whether the most urgent alarm(s) on the attribute are in the InAlarm state, whether or not they have been acknowledged.
Read-Only
AlarmMostUrgentMode
Enabled (default) whether or not alarms are configured on the attribute.
Read-Only
AlarmMostUrgentSeverity
Severity level expressed as an integer 1-4 of the most urgent alarm(s) on this attribute. If no alarm is in the InAlarm state or waiting to be Acked, the value is 0.
Read-Only
AlarmInhibit
If set to to TRUE, then the alarm is disabled (inhibited).
Supervisory, User
AlarmMode
The current alarm mode setting.
Read-Only
AlarmModeCmd
The command to set the alarm mode. Valid values are: Enable, Disable, Silence.
Supervisory, User
Bad.Condition
If TRUE, then the quality of the Discrete Attribute value is set to BAD.
Read-Only
Condition
Set to TRUE when Field Attribute value equals to the active alarm state value.
Read-Only
Input.DataType
The expected data type of the input reference value. This value is locked to boolean data type in the User Defined base template.
Read-Only
Input.ReadStatus
The cause of any errors that have occurred when data is read from the target reference. This is the Message Exchange status and not the status of the communication to external systems or devices such as Programmable Logic Controllers (PLCs).
Read-Only
Input.Value
The value that is "calculated" using data received via Message Exchange.
Read-Only
Msg
The state labels string representation of the Field Attribute value.
Read-Only
OffMsg
The string that holds the OffMsg attribute.
Read-Only
OnMsg
The string that holds the OnMsg attribute.
Read-Only
Output.DataType
The expected data type of the output reference value. This value is locked to boolean data type in the User Defined base template.
None
Output.Value
The placeholder for values that will be written to the target location.
Read-Only
Output.WriteStatus
The cause of any errors when writing data to the target location, or, in the case where that location is in a DeviceIntegration Object, the actual field I/O status. This status is the Message Exchange status and, when OutputDest is a DeviceIntegration Object, the status of the communication to external systems or devices such as Programmable Logic Controllers (PLCs).
Read-Only
Stats.LastResetTime
The last Date/Time set to the Reset attribute.
Read-Only
Stats.State0Cnt
The number of transitions to FALSE.
Read-Only
Stats.State0CntLast
The number of transitions to FALSE before setting the Reset attribute.
Read-Only
Stats.State0Duration
Time duration in the FALSE state.
Read-Only
Stats.State0DurationLast
Time duration in the FALSE state before setting the Reset attribute.
Read-Only
Stats.State0Time
The time of the last change to FALSE.
Read-Only
Stats.State1Cnt
The number of transitions to TRUE.
Read-Only
Stats.State1CntLast
The number of transitions to TRUE before setting the Reset attribute.
Read-Only
Stats.State1Duration
Time duration in the TRUE state.
Read-Only
Stats.State1DurationLast
Time duration in the TRUE state before setting the Reset attribute.
Read-Only
Stats.State1Time
The time to the last change to TRUE.
Read-Only
Stats.TimeSinceLastTransition
The time of the last change from TRUE to FALSE or from FALSE to TRUE.
Read-Only

Related Topics

Analog Run-Time Object Attributes

Attribute
Description
Run-Time Access (Supervisory, User, Read-Only, None)
AlarmCntsBySeverity
Array of counts of all alarms that are in UNACK_ALM, ACK_ALM, or UNACK_RTN states on the attribute, aggregated by severity levels 1-4.
Read-Only
AlarmMostUrgentAcked
TRUE (default) indicates that no alarms are in the InAlarm state or waiting to be Acked. A value of TRUE can also indicate that the most urgent alarm(s) on the attribute in the InAlarm state have been acknowledged, whether or not they are currently InAlarm.
Read-Only
AlarmMostUrgentInAlarm
FALSE (default) indicates that no alarms are in the InAlarm state or waiting to be Acked.
A value of FALSE also indicates whether the most urgent alarm(s) on the attribute are in the InAlarm state, whether or not they have been acknowledged .
Read-Only
AlarmMostUrgentMode
Enabled (default) whether or not alarms are configured on the attribute.
Read-Only
AlarmMostUrgentSeverity
Severity level expressed as an integer 1-4 of the most urgent alarm(s) on this attribute. If no alarm is in the InAlarm state or waiting to be Acked, the value is 0.
Read-Only
Bad.Condition
If TRUE, then the quality of the Analog Attribute value is set to BAD.
Read-Only
Stats.Average
The calculated average value of <AnalogAttribute> for the sample set.
Read-Only
Stats.Min
The lowest value from startup or reset of <AnalogAttribute>.
Read-Only
Stats.Max
The highest value from startup or reset of <AnalogAttribute>.
Read-Only
Stats.SampleSetMin
The lowest value from startup or reset that the <AnalogAttribute> has attained in the sample set.
Read-Only
Stats.SampleSetMax
The highest value from startup or reset that the <AnalogAttribute> has attained in the sample set.
Read-Only
Stats.StandardDeviation
The calculated standard deviation of <Analog Attribute>.
Read-Only
HiHi.Condition
Set to TRUE if the <AnalogAttribute> has exceeded the HiHi level limit.
Read-Only
HiHi.AlarmMode
The current alarm mode setting.
Read-Only
HiHi.AlarmModeCmd
The command to set the alarm mode. Valid values are: Enable, Disable, Silence.
Supervisory, User
HiHi.AlarmInhibit
If set to to TRUE, then the alarm is disabled (inhibited).
Supervisory, User
Hi.Condition
Set to TRUE if the <AnalogAttribute> has exceeded the Hi level limit.
Read-Only
Hi.AlarmMode
The current alarm mode setting.
Read-Only
Hi.AlarmModeCmd
The command to set the alarm mode. Valid values are: Enable, Disable, Silence.
Supervisory, User
Hi.AlarmInhibit
If set to to TRUE, then the alarm is disabled (inhibited).
Supervisory, User
Lo.Condition
Set to TRUE if the <AnalogAttribute> has exceeded the Lo level limit.
Read-Only
Lo.AlarmMode
The current alarm mode setting.
Read-Only
Lo.AlarmModeCmd
The command to set the alarm mode. Valid values are: Enable, Disable, Silence.
Supervisory, User
Lo.AlarmInhibit
If set to to TRUE, then the alarm is disabled (inhibited).
Supervisory, User
LoLo.Condition
Set to TRUE if the <AnalogAttribute> has exceeded the LoLo level limit.
Read-Only
LoLo.AlarmMode
The current alarm mode setting.
Read-Only
LoLo.AlarmModeCmd
The command to set the alarm mode. Valid values are: Enable, Disable, Silence.
Supervisory, User
LoLo.AlarmInhibit
If set to to TRUE, then the alarm is disabled (inhibited).
Supervisory, User
ValueClamped
Determines if the scaled value was clamped.
Read-Only
ValueOutOfRange
The updated attribute after a value is scaled to determine whether input value was out of range. This value is recalculated once a value is scaled again. The Quality should be set to the following: BAD quality if the raw value has BAD quality, to INITIALIZING quality if the raw value has INITIALIZING quality, and to GOOD quality otherwise.
Read-Only
ROC.Rate
The calculated rate of change of <AnalogAttribute>.
Read-Only
ROC.IncreasingHi.Condition
Set to TRUE if the <AnalogAttribute> has exceeded the Hi rate of change limit.
Read-Only
ROC.DecreasingHi.Condition
Set to TRUE if the <AnalogAttribute> has exceeded the Lo rate of change limit.
Read-Only
ROC.AlarmMode
The current alarm mode setting.
Read-Only
ROC.AlarmModeCmd
The command to set the alarm mode. Valid values are: Enable, Disable, Silence.
Supervisory, User
ROC.AlarmInhibit
If set to to TRUE, then the alarm is disabled (inhibited).
Supervisory, User
Dev.TargetChangeTime
If a change to target occurs after deployment, the time is logged. This time is then used to calculate the TimeSinceTargetChange attribute.
Read-Only
Dev.TimeSinceTargetChange
The elapsed time since the target was last changed.
Read-Only
Dev.Deviation
Calculates the current deviation between the <AnalogAttribute> and Dev.Target.
Read-Only
Dev.Major.Condition
Set to TRUE if the <AnalogAttribute> exceeds the Major Deviation limit.
Read-Only
Dev.Minor.Condition
Set to TRUE if the <AnalogAttribute> exceeds the Minor Deviation limit.
Read-Only
Dev.Minor.AlarmMode
The current alarm mode setting.
Read-Only
Dev.Minor.AlarmModeCmd
The command to set the alarm mode. Valid values are: Enable, Disable, Silence.
Supervisory, User
Dev.Minor.AlarmInhibit
If set to to TRUE, then the alarm is disabled (inhibited).
Supervisory, User
Dev.Major.AlarmMode
The current alarm mode setting.
Read-Only
Dev.Major.AlarmModeCmd
The command to set the alarm mode. Valid values are: Enable, Disable, Silence.
Supervisory, User
Dev.Major.AlarmInhibit
If set to to TRUE, then the alarm is disabled (inhibited).
Supervisory, User

Related Topics

Alarm Attributes

If an alarm attribute is enabled, then the following additional alarm attributes become available.

Attribute
Description
<Attribute>.Acked
Used to specify whether an alarm has been acknowledged. This attribute is updated when the AckMsg attribute is set. This attribute is always set to FALSE when a new alarm condition is detected (when the InAlarm attribute changes from FALSE to TRUE).
<Attribute>.AckMsg
The operator comment at the time the alarm is acknowledged. Any received text is stored, and the Acked attribute is set to TRUE. Also, the TimeAlarmAcked attribute is set to the current time. The maximum length is 256 characters.
<Attribute>.Category

The category of the alarm. The label of each alarm category is fixed.

 

<Attribute>.DescAttrName

The name of the attribute (within the same object) to be used as the alarm message. The attribute you specify must be of type String or InternationalizedString, with a maximum string length of 329 characters. If no attribute is specified, the Field Attribute description is used as the alarm message.

<Attribute>.InAlarm

The alarm state. This is exactly the same as the attribute in the host primitive that represents the alarm condition, except when the alarm state is disabled, in which case, InAlarm is set to Off, regardless of the actual condition state.

The quality is set during execute to the quality of the attribute, except when the alarm is disabled, in which case the quality is always GOOD.
<Attribute>.Priority

The value for the urgency of the alarm. Valid values are 1 through 999, with 1 being the most urgent.

 

<Attribute>.TimeAlarmAcked

The timestamp indicating the last time this alarm was acknowledged. The date format reflects the current locale setting for the operating system.

 

<Attribute>.TimeAlarmOff

The timestamp indicating the last time this alarm (as represented by the InAlarm attribute) went off. The date format reflects the current locale setting for the operating system.

 

<Attribute>.TimeAlarmOn

The timestamp indicating the last time this alarm (as represented by the InAlarm attribute) went on. The date format reflects the current locale setting for the operating system.

 

Related Topics

Alarm Aggregation Attributes on Objects

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.

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

Related Topics

Alarm Shelving Attributes

The following attributes support alarm shelving.

Attribute
Description
Run-Time Access (Supervisory, User, Read-Only, None)
<Attribute>.AlarmShelveCmd
Use this attribute to shelve or unshelve an alarm.
Default values: Duration = 0, Reason = ""
Supervisory, User
<Attribute>.AlarmShelved
Boolean value. Shows True if alarm is shelved, False if alarm is unshelved.
Default value: False
Read-Only
<Attribute>.AlarmShelveStartTime
A date/time stamp indicating when alarm shelving began, based on the engine time when the shelving request was received,
Default value: Blank
Read-Only
<Attribute>.AlarmShelveStopTime
A date/time stamp equal to the AlarmShelveStartTime plus the duration for which the alarm is to be shelved.
Default value: Blank
Read-Only
<Attribute>.AlarmShelveReason
A string value providing the reason for which the alarm was shelved or un-shelved by the Alarm Shelve command.
Default value: Blank (See AlarmShelveCmd attribute.)
Read-Only
<Attribute>.AlarmShelveUser
The name of the user who most recently shelved or un-shelved the alarm with the Alarm Shelve command.
Default value: Blank
Read-Only
<Attribute>.AlarmShelveNode
The name of the computer node from which the user most recently shelved or un-shelved the alarm with the Alarm Shelve command.
If the node is hosted in a Terminal Server client session, the node and the TSE ID are both identified.
Default value: Blank
Read-Only

History 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.

Related Topics

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11/19/14