ViewEngine Object

You use the ViewEngine object to host InTouchViewApp objects. The ViewEngine object supports common engine features such as deployment, undeployment, startup, and shutdown. The ViewEngine does not support redundancy.

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

About the ViewEngine Object

A ViewEngine object is a simplified version of an AppEngine object. A ViewEngine object hosts only InTouchViewApp objects, and does not support redundancy.

The ViewEngine object does not need to be running in order for WindowViewer to execute its scripts or access process data.

The ViewEngine object can host Appserver scripts and attributes. The ViewEngine scripts continue to run when WindowViewer is shutdown.

The ViewEngine object provides a set of configuration and run-time attributes for the ViewEngine.

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 Object Help in the Help file header.

Run-Time Behavior

Run-time behavior pertains to the running state of a deployed ViewEngine object. The most important function of the running ViewEngine is its scheduler. The ViewEngine has a scan-based scheduler that triggers at the configured scan period, specified in milliseconds. Each scan period interval, the ViewEngine executes every object on the engine, including itself.

Since the ViewEngine object will generally host only a few InTouchViewApp objects, you may want to reduce the ScanPeriod to minimize the latency of tag value updates when referencing tags as InTouchViewApp attributes.

Once deployed and operating, the ViewEngine object can assume one of the following states:

Configuration

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

State Change	Behavior
Startup	In this transition state, the ViewEngine object starts as a new operating system process and starts all of the objects that it hosts. Objects hosted by the ViewEngine object are: Initialized from checkpoint data, which is the configuration, state, and all associated data necessary to support restarting an object in its most recent condition. This data is periodically stored to the computer hard drive when the ViewEngine is running. Started by the engine. Registered with message exchange (the object-to-object messaging system) upon successful startup. Executed by the scheduler.
Going onscan	The ViewEngine object notifies all of the InTouchViewApp objects that it hosts that the engine has been put OnScan.
Going offscan	The ViewEngine object notifies all of the InTouchViewApp objects that it hosts that the engine is offscan (inoperative).
Shutdown	The ViewEngine object shuts down as an operating system process. Before doing so, one final checkpoint is performed after all InTouchViewApp objects hosted by the ViewEngine object are: Unregistered with Message Exchange (the object-to-object messaging system). Stopped.

Topic Category	Topic Subcategory	Topic Details
Configuration	General Configuration
Alarm Configuration
Scheduler History Configuration
Engine History Configuration

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

General Configuration

Use the General tab to configure general aspects of the ViewEngine object, such as startup options, historian options, and scripting options.


Editor Option	Associated Attribute	Description	Run-Time Access (Supervisory, User, Read-Only, None)
Engine startup type	Engine.StartupType	The type of startup for the object the next time startup occurs: Auto, SemiAuto, or Manual. For an automatic startup, the ViewEngine starts automatically in the last check-pointed scan state. A semi-automatic startup is the same as an automatic startup, except that the Engine starts in an offscan state. For a manual start, the ViewEngine must be started using the System Management Console.	Supervisory, User
Restart the engine when it fails	Engine.RestartOnFailure	If enabled, the ViewEngine object will automatically attempt to restart if a failure occurs. A failure to start is defined as an ViewEngine object failing within five minutes of startup. Therefore, if an engine operates longer than five minutes and then fails, and this option has been selected, three subsequent attempts will be made to start the engine. If an engine fails to start three times in a row, within five minutes, no more attempts are made to start it.	Supervisory, User
Scan period	Scheduler.ScanPeriod	The period of time, in milliseconds, in which the ViewEngine object executes all onscan hosted objects in a sequential order. This is a single thread of execution that represents the desired rate of execution for each of the hosted object. If the time to execute all objects is shorter than the scan period, the remaining time is used by the AppEngine object to process outgoing requests, incoming requests, and checkpoint snapshots. If the time to execute all objects extends beyond the scan period, a "scan overrun" occurs, and the next execution period will not start until the beginning of the next scan period. You may want to use a short ScanPeriod to minimize the latency of tag value updates when referencing tags as InTouchViewApp attributes.	Supervisory, User
Enable storage to historian	Engine.Historian.Enabled	If enabled, the values for attributes that have historization enabled will be stored to the specified historian.	None
Enable Tag Hierarchy	Engine.Historian.EnableTagHierarchy	If enabled, the model view is automatically replicated to the Wonderware Historian node associated with the Galaxy. You can control this behavior at run time without undeploying and redeploying the engine of any affected objects.	Supervisory, User
Historian	Engine.Historian.Connection	The string to use for the connection to the historian. For the Wonderware Historian, this is the node name. If two Historian Servers are configured as partners, the node identified by this string becomes the primary historian for this engine. The partner information is configured and maintained on the Historian Server. Click the ellipse button to browse for the historian on the network.	Read-Only
TCP Port	Engine.Historian.ConnectionTCPPort	The TCP port on the Historian Server node to which history data will be sent. The TCP port is configured when the Historian Server is installed. The default is 32568.	Read-Only
Enable compression	Engine.Historian.CompressionEnable	If enabled, history data is compressed before it is sent over the network to the Historian Server. This is used to reduce network utilization, but enabling this setting will increase the CPU load.	Read-Only
Throttling network bandwidth	Engine.Historian.BandwidthLimit	Specifies limit of bandwidth usage, in kbps, for network communication used by HCAL when communicating with the Wonderware Historian. A value of 0 disables this feature (default). For more information on estimating your bandwidth needs, see the performance and sizing recommendations for the Historian Server in the Wonderware System Platform Installation Guide. On networks with limited bandwidth (for example, 256 kbps) you may want keep half of the bandwidth available for other traffic, so you would set this value to 128 kbps. Consider when the historian connection is lost, and store-and-forward data has accumulated on AppEngine nodes. When the connection between an AppEngine node and historian is restored, all the store-and-forward data is sent at once, and may use the entire network bandwidth (on a slow network) and cause the AppEngines to again lose communication with the Historian and go into store-and-forward data again. By setting a limit here of 2/3 the total bandwidth, this problem of AppEngines going in and out of store-and-forward can be avoided. This limit applies to all history-related communication, including tag creation, sending real-time data, sending late data, and sending store-and-forward data.	Read-Only
Wait to send incomplete packets	Engine.Historian.BufferAgeLimit	Specifies the maximum time, in milliseconds, for keeping a partially-filled Historian Client Access Layer (HCAL) buffer before sending it to the Historian Server. If the buffer is full, then it is sent immediately, regardless of any value configured in this field. If you have fast-changing data, this setting is irrelevant. If you have slow-changing data and limited network bandwidth, you might want to increase this value so that you have less "chatter" on the network. The default is 1,000 milliseconds. Valid values are between 1,000 and 30,000 milliseconds.	Read-Only
Pre-processing buffer size	Engine.Historian.BufferSize	The total size, in MB, of all buffers used by Historian Client Access Layer (HCAL). The default and minimum value is 8. If you have very high data bursts, then you should increase this value. If this is too low, data loss occurs and error messages related to buffer overflows appear in the ArchestrA Logger. Increase this value in increments of 10 MB.	Supervisory, User
Store forward threshold	Engine.Historian.StoreForwardDeletionThreshold	The size, in MB, of free space to reserve on the HCAL store-and-forward disk. The space designated will not be used during store-and-forward. This value cannot be a negative number.	Read-Only
Store forward minimum duration	Engine.Historian.StoreForwardMinDuration	The minimum duration, in seconds, for HCAL to function in store-and-forward mode. HCAL will function in store-and-forward mode for this length of time even if the condition that caused HCAL to function in store-and-forward mode no longer exists.	Supervisory, User
Maximum time for scripts to execute	Engine.ScriptExecuteTimeout.Limit	The time, in milliseconds, allowed for any synchronous script primitive to execute before an alarm is raised on that script primitive. This timeout applies to script primitives attached directly to the AppEngine object, as well as to ApplicationObjects hosted by the AppEngine object. Note that configuration security means that this attribute can only change when the AppEngine object is offscan, thus allowing the optimization of the script engine, since it only needs to read the attribute once when going onscan. The maximum value is limited to the Scheduler.ScanPeriod for the AppEngine object.	User
Maximum asynchronous thread count	Engine.AsyncScriptThreadMax	The maximum number of asynchronous script threads that can be executing simultaneously.	Read-Only
Checkpoint period	Scheduler.CheckpointPeriod	The interval, in milliseconds, at which checkpointing should be performed. If set to 0, checkpointing will be performed as fast as possible as a background task.	Supervisory, User
Checkpoint directory location	Engine.CheckpointPath	The path where the checkpoint files will be located. If you do not specify a location, the system default path will be used. If the specified location is not accessible, a warning will be logged. If the location you specify does not currently exist, it will be created. You cannot use a virtual drive or a UNC path for the checkpoint directory location.	Read-Only
Alarm throttle limit	Engine.AlarmThrottleLimit	The limit for the number of alarms per second that can be raised by the object before throttling occurs. If set to 0, alarm throttling is disabled.	User
Statistics average period	Scheduler.StatsAvgPeriod	The frequency, in milliseconds, that averaged attribute values are updated. This value must be greater than or equal to the scan period. The average is a running average; that is, values are accumulated for an attribute over the period of time set for this attribute. The value of this attribute affects the run-time values at any given time of all other attributes of the same type of object that are averaged and can be used to "slow down" the updating of the cycle-oriented statistics.	Supervisory, User
Maximum input queue size	Scheduler.InputQueueSizeMaxAllowed	The maximum size for the object input queue. The default is 16 MB. An object's input queue receives all system level messages, such as publish packets, heartbeats, gets, sets, and so on. These messages are then processed by the system. The input queue size grows and shrinks over time. Should the input queue grow to its maximize size, messages are not queued until messages in the queue are processed, making room for additional ones. Valid values are 2 through 128.	Read-Only
Engine failure timeout	Engine.EngineFailureTimeout	The amount of time, in milliseconds, that the engine can run without notifying the bootstrap of its health. After this time elapses, the EngineFailureAlarm attribute is set TRUE in the WinPlatform object. Be sure that you specify a time long enough to accommodate the completion of any engine-related actions that might prevent or delay the bootstrap notification (for example, cascade deployment of objects with a large number of scripts). Internally, the system will triple the value that you specify for this attribute.	Supervisory, User
Maximum number of consecutive data notification failures allowed	Engine.DataNotifyFailureConsecMax	The number of consecutive data change notification failures that will be allowed before the subscription is stopped by the publisher engine.	Supervisory, User

Alarm Configuration

Use the Alarms tab to enable alarming for various engine-related conditions.

Scheduler History Configuration

Editor Option	Associated Attribute	Description	Run-Time Access (Supervisory, User, Read-Only, None)
Report checkpoint failure alarm	Engine.CheckPointFailed.Alarmed	If enabled, an alarm will be triggered when the checkpoint operation fails to checkpoint the last object condition.	None
Priority	Engine.CheckPointFailed.Priority	See Alarm Attributes.	Supervisory, User
Report object quarantined condition	Engine.ObjectQuarantined.Alarmed	If enabled, an alarm will be triggered when at least one hosted object is in a quarantined state, indicating a software exception has occurred on the object. If all quarantined objects are later undeployed, the alarm will be disabled.	None
Priority	Engine.ObjectQuarantined.Priority	See Alarm Attributes.	Supervisory, User
Report subscription folding condition	Engine.Folding.Alarmed	If enabled, an alarm will be triggered when Message Exchange folding is currently active, which means that this object is overloaded with regards to publishing throughput. Folding occurs when the object detects that a target object is receiving more data than it can process in a timely manner.	None
Priority	Engine.Folding.Priority	See Alarm Attributes.	Supervisory, User
Report scan overrun condition	Scheduler.ScanOverrun.Alarmed	If enabled, an alarm will be raised if a scan overrun condition occurs.	None
Consecutive scan overrun limit	Scheduler.ScanOverrun.HiLimit	The maximum number of consecutive scan overruns that are allowed before an alarm is raised. A value of -1 will prevent overruns from being checked against a limit.	Supervisory, User
Priority	Scheduler.ScanOverrun.Priority	See Alarm Attributes.	Supervisory, User

Use the Scheduler History tab to enable historization for various status averages and counts that are generated by the internal scheduler of the ViewEngine object.


Editor Option	Associated Attribute	Description	Run-Time Access (Supervisory, User, Read-Only, None)
Historize check point period average	Scheduler.CheckpointPeriodAvg.Historized	If enabled, the system will historize the average number of milliseconds between checkpoints for the averaging period.	None
Historize execution time average	Scheduler.ExecutionTimeAvg.Historized	If enabled, the system will historize the average number of milliseconds required to execute all objects per cycle.	None
Historize housekeeping time average	Scheduler.HousekeepingTimeAvg.Historized	If enabled, the system will historize the average number of milliseconds required for this object to do housekeeping tasks per cycle.	None
Historize time idle average	Scheduler.TimeIdleAvg.Historized	If enabled, the system will historize the average number of milliseconds per scan period that the object is idle (for example, receiving data, or sending data).	None
Historize input message size average	Scheduler.InputMsgSizeAvg.Historized	If enabled, the system will historize the average size of an input message, in bytes, for this averaging period.	None
Historize input messages processed average	Scheduler.InputMsgsProcessedAvg.Historized	If enabled, the system will historize the average number of input messages, in total bytes, in the input queue per scan period (including deferred and processed messages).	None
Historize input messages queued average	Scheduler.InputMsgsQueuedAvg.Historized	If enabled, the system will historize the average number of messages queued, including processed and deferred messages, per scan period. The value is calculated for the averaging period.	None
Historize input queue size average	Scheduler.InputQueueSizeAvg.Historized	If enabled, the system will historize the average size, in MB, of the input queue during the averaging period.	None
Historize time input average	Scheduler.TimeInputAvg.Historized	If enabled, the system will historize the average number of milliseconds required to process input messages per scan period.	None
Historize time output average	Scheduler.TimeOutputAvg.Historized	If enabled, the system will historize the average number of milliseconds required to process output messages per scan period.	None
Historize scan overrun count	Scheduler.ScanOverrunsCnt.Historized	If enabled, the system will historize the number of scan overruns since the last time statistics were reset.	None
Historize R/W Interrupts time average	Scheduler.ExecInterruptsTimeAvg.Historized	If enabled, the system will historize the average number of milliseconds required to perform execution interrupts per engine scan cycle.	None
Force storage period	<AttributeName>.ForceStoragePeriod	See History Attributes.	Supervisory, User
Value deadband	<AttributeName>.Deadband	See History Attributes.	Supervisory, User
Trend high	<AttributeName>.TrendHi	See History Attributes.	Supervisory, User
Trend low	<AttributeName>.TrendLo	See History Attributes.	Supervisory, User
Interpolation Type	<AttributeName>.InterpolationType	See History Attributes.	Supervisory, User
Sample Count	<AttributeName>.SampleCount	See History Attributes.	Supervisory, User
Rollover Value	<AttributeName>.RolloverValue	See History Attributes.	Supervisory, User
Enable Swinging Door	<AttributeName>.EnableSwingingDoor	See History Attributes.	Supervisory, User
Rate DeadBand	<AttributeName>.RateDeadBand	See History Attributes.	Supervisory, User

Engine History Configuration

Use the Engine History tab to enable historization for various status counts that are generated by the ViewEngine object.


Editor Option	Associated Attribute	Description	Run-Time Access (Supervisory, User, Read-Only, None)
Historize external reference count	Engine.ExternalReferenceCnt.Historized	If enabled, the system will historize the number of registered external references.	None
Historize external reference count unbound	Engine.ExternalReferenceCntUnbound.Historized	If enabled, the system will historize the number of registered external references that are unbound.	None
Historize issued external gets count	Engine.IssuedExternalGetsCnt.Historized	If enabled, the system will historize the number of off-engine gets (initiated from AutomationObjects on this object).	None
Historize issued external sets count	Engine.IssuedExternalSetsCnt.Historized	If enabled, the system will historize the number of off-engine sets (initiated from AutomationObjects on this object).	None
Historize issued internal gets count	Engine.IssuedInternalGetsCnt.Historized	If enabled, the system will historize the number of on-engine gets (initiated from AutomationObjects on this object).	None
Historize issued internal sets count	Engine.IssuedInternalSetsCnt.Historized	If enabled, the system will historize the number of on-engine sets (initiated from AutomationObjects on this object).	None
Historize received external gets count	Engine.RcvdExternalGetsCnt.Historized	If enabled, the system will historize the number of incoming external gets (received from other engine objects that do not exist on this object).	None
Historize received external sets count	Engine.RcvdExternalSetsCnt.Historized	If enabled, the system will historize the number of incoming external sets (received from other engine objects that do not exist on this object).	None
Historize alarms throttled flag	Engine.AlarmsThrottled.Historized	If enabled, the system will historize the number of alarms that have been throttled in the prior scan. The limit for the number of alarms per second that can be raised by this object before throttling occurs is set using the alarm throttle limit.	None
Historize publish packets received count	Engine.PublishPacketsRcvdCnt.Historized	If enabled, the system will historize the number of publish packets received on this engine from other engines.	None
Historize publish packets sent count	Engine.PublishPacketsSentCnt.Historized	If enabled, the system will historize the number of publish packets sent from this engine to other engines.	None
Force storage period	<AttributeName>.ForceStoragePeriod	See History Attributes.	Supervisory, User
Value deadband	<AttributeName>.Deadband	See History Attributes.	Supervisory, User
Trend high	<AttributeName>.TrendHi	See History Attributes.	Supervisory, User
Trend low	<AttributeName>.TrendLo	See History Attributes.	Supervisory, User
Interpolation Type	<AttributeName>.InterpolationType	See History Attributes.	Supervisory, User
Sample Count	<AttributeName>.SampleCount	See History Attributes.	Supervisory, User
Rollover Value	<AttributeName>.RolloverValue	See History Attributes.	Supervisory, User
Enable Swinging Door	<AttributeName>.EnableSwingingDoor	See History Attributes.	Supervisory, User
Rate DeadBand	<AttributeName>.RateDeadBand	See History Attributes.	Supervisory, User

Run-Time Object Attributes

Topic Category	Topic Subcategory	Topic Details
Run-Time Object Attributes	Alarm Aggregation Attributes
History Attributes
Alarm Attributes

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

For a list of common object attributes, click Object 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.	Read-Only
AlarmOnCnt	The number of active alarms in the distributor. Does not include sub-areas or sub-notification-distributors.	Read-Only
AlarmUnAckCnt	The number of unacknowledged alarms in the distributor (including unacknowledged return-to-normals). Does not include sub-areas or sub-notification-distributors.	Read-Only
Engine.AlarmsThrottled	The number of alarms that have been throttled in the prior scan. The limit for the number of alarms per second that can be raised by this object before throttling occurs is set using the alarm throttle limit.	Read-Only
Engine.AsyncScriptsRunningCnt	The total number of asynchronous scripts that are currently executing on the object.	Read-Only
Engine.AsyncScriptsWaitingCnt	The total number of asynchronous scripts that are currently queued to execute on the object, but are not yet executing because they are waiting for a free thread.	Read-Only
Engine.CheckPointFailed.Condition	Used to indicate whether the checkpointer failed to checkpoint the last attempt.	Read-Only
Engine.EngineAlarmRate	The number of alarms raised on this object during the prior scan by all objects running on this object, calculated as alarms per second. When alarm throttling occurs, the maximum value is the alarm throttle limit. This value is updated by the Notification Distributor.	None
Engine.ExternalReferenceCnt	The number of registered external references. For extra quality information, see Quality Handling.	Read-Only
Engine.ExternalReferenceCntUnbound	The number of registered external references that are unbound. For extra quality information, see Quality Handling.	Read-Only
Engine.Folding.Condition	Set to TRUE when Message Exchange folding is currently active, which means that this object is overloaded with regards to publishing throughput. Folding occurs when the object detects that a target object is receiving more data than it can process in a timely manner.	Read-Only
Engine.GlobalAdviseOnlyActiveEnabled	If set to TRUE, Galaxy-wide advising of only active items is enabled.	Read-Only
Engine.Historian.BufferCount	Obsolete. Do not use. Use the BufferSize attribute instead.	Read-Only
Engine.Historian.ConnectionPartner	The name of the partner Historian Server, if one is configured for the Historian. If no partner Historian is detected, the value of this attribute is an empty string.	Read-Only
Engine.Historian.ConnectState	The physical state of the connection between HCAL and the historian. This value should remain TRUE as long as HCAL is able to communicate with the historian, regardless of whether it is historizing data or not. A network failure, for example, will cause the ConnectState attribute to be set to FALSE. Even if the ConnectState attribute is FALSE, the AppEngine may still be connected to the historian and appear listed as a client in the historian System Management Console. In a redundant historian setup, the connect state is TRUE if the connection is good for at least one of the historians. To determine state of an individual historian in a redundant setup, use the ConnectStateMask attribute.	Read-Only
Engine.Historian.ConnectStateCmd	The ConnectStateCmd attribute is used to control the state of historization between the engine and the historian. If this value is set to FALSE, the engine will stop sending updates to HCAL, and HCAL will disconnect from the historian to ensure that a gap is displayed on a history trend. HCAL will disconnect from the historian even though it is able to communicate with it, as reflected by the ConnectState attribute.	Supervisory, User
Engine.Historian.ConnectStateMask	A bitmask where the lowest order bit represents the connection state of the primary Historian and the second bit represents the connection state of the partner. If no partner is configured, the second bit will always be 0.	Read-Only
Engine.Historian.ForwardingChunkSize	Obsolete. Do not use.	Read-Only
Engine.Historian.ForwardingDelay	Obsolete. Do not use.	Read-Only
Engine.Historian.InStoreForward	If set to TRUE, HCAL is in store-and-forward mode. In a redundant historian setup, the InStoreForward attribute is TRUE if either one of the historians is in store-and-forward mode. To determine state of an individual historian in a redundant setup, use the InStoreForwardMask attribute.	Read-Only
Engine.Historian.InStoreForwardMask	A bitmask where the lowest order bit represents the store-and-forward state of the primary Historian and the second bit represents the store-and-forward of the partner. If no partner is configured, the second bit will always be 0.	Read-Only
Engine.Historian.ProcessInterval	Obsolete. Do not use.	Read-Only
Engine.Historian.StoreForwardProblem	If set to TRUE, the HCAL on the active engine is unable to store data while in store-and-forward mode. In a redundant historian setup, the StoreForwardProblem attribute is TRUE if either one of the historians has a store-and-forward issue.	Read-Only
Engine.Historian.StoreForwardSpaceAvailable	The available storage space, in MB, for the HCAL of the active engine.	Read-Only
Engine.Historian.StoreFwdDataLost	Set to TRUE when HCAL is in store-and-forward mode, the store-and-forward deletion threshold has been exceeded, and history data has been lost. This value remains TRUE until the connection to the historian has been re-established and store-and-forward is no longer in effect.	Read-Only
Engine.IssuedExternalGetsCnt	The number of off-engine gets (initiated from AutomationObjects on this object). For extra quality information, see Quality Handling.	Read-Only
Engine.IssuedExternalSetsCnt	The number of off-engine sets (initiated from AutomationObjects on this object). For extra quality information, see Quality Handling.	Read-Only
Engine.IssuedInternalGetsCnt	The number of on-engine gets (initiated from AutomationObjects on this object). For extra quality information, see Quality Handling.	Read-Only
Engine.IssuedInternalSetsCnt	The number of on-engine sets (initiated from AutomationObjects on this object). For extra quality information, see Quality Handling.	Read-Only
Engine.ObjectQuarantined.Condition	Used to trigger an alarm when at least one hosted object is in a quarantined state, indicating a software exception has occurred on the object. If all quarantined objects are later undeployed, the alarm will be disabled.	Read-Only
Engine.Objects	An array containing the names of all objects hosted by this object.	Read-Only
Engine.ProcessCPULoad	The current processor load that the engine is consuming.	Read-Only
Engine.ProcessIODataBytes	The current rate, in bytes per second, that the engine is reading and writing I/O bytes. I/O bytes include network bytes, file bytes, and all device I/O bytes.	Read-Only
Engine.ProcessPageFaults	The current page fault rate, per second, for the engine.	Read-Only
Engine.ProcessPrivateBytes	The current private bytes of memory that the engine has allocated.	Read-Only
Engine.ProcessWorkingSet	The current number of bytes in the working set of the engine. The working set is the amount of memory that the operating system has dedicated for the engine process.	Read-Only
Engine.PublisherDataNotifyFailureCnt	The total number of times that the engine, acting as a publisher, failed to send data change notifications to a subscriber.	Read-Only
Engine.PublishPacketsRcvdCnt	The number of publish packets received on this engine from other engines. For extra quality information, see Quality Handling.	Read-Only
Engine.PublishPacketsSentCnt	The number of publish packets sent from this engine to other engines. For extra quality information, see Quality Handling.	Read-Only
Engine.RcvdExternalGetsCnt	The number of incoming external gets (received from other engine objects that do not exist on this object). For extra quality information, see Quality Handling.	Read-Only
Engine.RcvdExternalSetsCnt	The number of incoming external sets (received from other engine objects that do not exist on this object). For extra quality information, see Quality Handling.	Read-Only
Engine.StartingFromCheckpoint	If set to TRUE, an engine is starting and restoring a checkpoint file.	Read-Only
Engine.StartupReason	Indicates whether an engine is starting after deployment, from a checkpoint, or from standby (failover). Valid values are: Starting_AfterDeploy, Starting_FromCheckpoint, Starting_FromStandby.	Read-Only
Engine.StatsReset	Used to reset all statistics during run time.	Supervisory, User
Engine.SubscribedAttrCnt	The number of attributes on this engine, including the attributes of all objects hosted on this engine, that are being subscribed to (read) by other engines and their hosted objects and anonymous engines, such as the Object Viewer and InTouch.	Read-Only
Engine.SubscribedObjectCnt	The number of objects on this engine that have one or more attributes that are subscribed to by other engines.	Read-Only
Engine.SubscriberEngineCnt	The number of other engines that are subscribing to attributes on this engine. For example, if InTouch View is displaying 10 attributes from this engine, and objects hosted on another AppEngine are reading data from five objects on this engine, then the value is 2.	Read-Only
Engine.SubscriptionAttemptCnt	The total number of subscriptions initiated by this engine.	Read-Only
Engine.SubscriptionCancelledCnt	The total number of subscriptions initiated by this engine that were cancelled by the publisher.	Read-Only
Engine.SubscriptionFailureCnt	The total number of subscription failures detected by this engine.	Read-Only
Engine.SubscriptionFailureCommsCnt	The number of subscription failures detected by this engine that resulted from platform or engine communications errors.	Read-Only
Engine.SubscriptionFailureConfigCnt	The total number of times that the engine, acting as a publisher, failed to send data change notifications to a subscriber.	Read-Only
Engine.SubscriptionLocalCnt	The current number of active subscriptions to an engine on the local platform.	Read-Only
Engine.SubscriptionRemoteCnt	The current number of active subscriptions to an engine on a remote platform.	Read-Only
Engine.SuspendedAttributeCnt	The number of attributes on this engine that are currently in a suspended (or inactive) state.	Read-Only
Scheduler.CheckpointPeriodAvg	The average number of milliseconds between checkpoints for the averaging period. For extra quality information, see Quality Handling.	Read-Only
Scheduler.ExecInterruptsTimeAvg	The average number of milliseconds required to perform execution interrupts per engine scan cycle. For extra quality information, see Quality Handling.	Read-Only
Scheduler.ExecutionTimeAvg	The average number of milliseconds required to execute all objects per cycle. For extra quality information, see Quality Handling.	Read-Only
Scheduler.HousekeepingTimeAvg	The average number of milliseconds required for this object to do housekeeping tasks per cycle. For extra quality information, see Quality Handling.	Read-Only
Scheduler.InputMsgSizeAvg	The average size of an input message, in bytes, for this averaging period. For extra quality information, see Quality Handling.	Read-Only
Scheduler.InputMsgsProcessedAvg	The average number of input messages, in total bytes, in the input queue per scan period (including deferred and processed messages). For extra quality information, see Quality Handling.	Read-Only
Scheduler.InputMsgsQueuedAvg	The average number of messages queued, including processed and deferred messages, per scan period. The value is calculated for the averaging period. For extra quality information, see Quality Handling.	Read-Only
Scheduler.InputMsgsQueuedMax	The maximum value of the average number of queued input messages since the last statistics reset. For extra quality information, see Quality Handling.	Read-Only
Scheduler.InputQueueSizeAvg	The average size, in MB, of the input queue during the averaging period. For extra quality information, see Quality Handling.	Read-Only
Scheduler.InputQueueSizeMax	The maximum value of the average input queue size since the statistics were last reset. For extra quality information, see Quality Handling.	Read-Only
Scheduler.ObjectCnt	The number of objects, excluding the AppEngine object.	Read-Only
Scheduler.ObjectsOffScanCnt	The number of offscan objects, excluding the AppEngine object.	Read-Only
Scheduler.ScanCyclesCnt	The number of execution cycles since the statistics were last reset.	Read-Only
Scheduler.ScanOverrun.Condition	A Boolean condition alarm flag indicating a scan overrun condition. This value is set to FALSE when the object goes offscan.	Read-Only
Scheduler.ScanOverrunsCnt	The number of scan overruns since the last time statistics were reset.	Read-Only
Scheduler.ScanOverrunsConsecCnt	The number of consecutive scan overruns. This value increments by 1 when a scan overrun occurs. This value is set to 0 when the object goes offscan.	Read-Only
Scheduler.ScanTime	The current, local, system time for a given scan of the AppEngine that contains this scheduler. The date format reflects the current locale setting for the operating system. For extra quality information, see Quality Handling.	Read-Only
Scheduler.StatsReset	Used to reset all statistics during run time.	Supervisory, User
Scheduler.TimeIdleAvg	The average number of milliseconds per scan period that the object is idle (for example, receiving data, or sending data). For extra quality information, see Quality Handling.	Read-Only
Scheduler.TimeIdleMax	The maximum value for the TimeIdleAvg attribute since statistics were reset or since the engine went onscan. For extra quality information, see Quality Handling.	Read-Only
Scheduler.TimeIdleMin	The minimum value for the TimeIdleAvg attribute since statistics were reset or since the engine went onscan. For extra quality information, see Quality Handling.	Read-Only
Scheduler.TimeInputAvg	The average number of milliseconds required to process input messages per scan period. For extra quality information, see Quality Handling.	Read-Only
Scheduler.TimeOutputAvg	The average number of milliseconds required to process output messages per scan period. 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.

History Attributes

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

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


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.

Alarm Attributes

If an alarm attribute is enabled, then the following additional alarm attributes become available. None of these attributes can be alarmed.

Quality Handling

For the following attributes, data quality is set to BAD when the object goes offscan, set to INITIALIZING when the object goes onscan, and set to GOOD when the object is updated during execution.

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>.AlarmMode	The current alarm mode setting. Valid values are: Enable, Disable, Silence.
<Attribute>.AlarmModeCmd	The command to set the alarm mode. Valid values are: Enable, Disable, Silence.
<Attribute>.Category	The category of the alarm. The label of each alarm category is fixed.
<Attribute>.DescAttrName	The description of the alarm. The description must be of type String or InternationalizedString, with a maximum length of 329 characters. The DescAttrName attribute can contain a static alarm description or a reference to another string attribute within the same object containing the alarm description. The reference must be in the form: "me.AttrName". If the reference is invalid, the actual reference string is used for the description. If nothing is supplied for the DescAttrName attribute, the object’s ShortDesc attribute is used at run time.
<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>.Inhibit	If true, the alarm is disabled. This attribute is intended to be written to by a script, a user, or an input feature. Only the individual alarm is disabled. No other alarms are disabled in the same object or in any objects that are assigned to or contained by this object.
<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.