DDESuiteLinkClient Object

DDESuiteLinkClient ObjectThe DDESuiteLinkClient object functions as the ArchestrA DDE/SuiteLink Client for third-party DDE Servers and Wonderware™ I/O Servers through DDE and SuiteLink protocols.For more information, click on a Help topic.∙Overview∙Run-Time Behavior∙Configuration∙Run-Time Object AttributesOverviewThe DDESuiteLinkClient object is a key member of the core set of AutomationObjects within the ArchestrA system infrastructure. The DDESuiteLinkClient object is a DeviceIntegration object that allows access to a running I/O Server. A DDE or SuiteLink I/O Server can provide data points to Galaxy application objects through the DDESuiteLinkClient object.Note The DDESuiteLinkClient object is compatible with all FactorySuite™ 2000 version I/O Servers and components.There is a one-to-one relationship between an instance of the DDESuiteLinkClient object and a running I/O Server. If you want to reference data points in more than one I/O Server, you must configure and deploy more than one DDESuiteLinkClient object. For example, you would need to configure one DDESuiteLinkClient object to communicate to an ABTCP I/O Server and another one to talk to the GEHCS I/O Server.When you configure the DDESuiteLinkClient object, you can specify one or more I/O Server topics to which access is required. At run time, all items that the Galaxy application requires for a specified topic will be updated with the latest values from the I/O Server. The rate at which the values are updated depends on how the topics were configured within the target I/O Server.If you want to connect to a DDE I/O Server, you will need to specify login information that the DDESuiteLinkClient object will use to connect to the I/O Server.From other objects and from scripts, you can reference the topics you configured for the DDESuiteLinkClient object. For example, you might configure the input source for a FieldReference object to reference an item for one of the topics. Thus, the FieldReference object input source would be receiving data from an I/O Server via the DDESuiteLinkClient object.To aid in rapid application development, you can create a list of topic items that will appear in the ArchestrA Attribute Browser. To do this, you will need to specify the item address and associate it with a user-defined attribute name (alias). Creating the item list is not required in order to reference data from the I/O Server.The reference syntax for a DDESuiteLinkClient object data point is:<objectname>.<topicname>.<itemname>OR<objectname>.<topicname>.<attributename>The <objectname> is the name that you choose to give to the DDESuiteLinkClient object.Each I/O topic for a DDESuiteLinkClient object is also known as a "scan group." Run-time object attributes allow you to monitor errors related to the data quality for item values in a scan group.Items in a scan group are “dynamic” in that they are create d or activated dynamically during run time.If the I/O Server provides time with value and quality (VTQ), the time stamp from the I/O Server is used to update the attribute. Otherwise, the current time provided by the hosting AppEngine is used. If the quality for a dynamic attribute changes, but the data value does not change, the current time provided by the hosting AppEngine is used. When a poke request is received for a BlockWrite item, the time stamp provided is used to update the attribute. Otherwise, the current time of the hosting AppEngine is used.For general information on objects, including relationships, deployment, and alarm distribution, see the Integrated Development Environment (IDE) documentation.For information on configuration options for object information, scripts, user-defined attributes (UDAs), or attribute extensions, click Extensions Help in the Help file header.Related TopicsRun-Time BehaviorConfigurationRun-Time Object AttributesTerminal Services or Remote Desktop ConsiderationsWhen configuring the DDESuiteLinkClient object for DDE, make sure that the DDE Server is started and running in the same session as the DDESuiteLinkClient object. One way to accomplish this is to configure the DDE Server to run as a service. You could also include the DDE Server in the Windows startup folder.Related TopicsConfigurationRun-Time BehaviorThe following information describes the run-time behavior of DDESuiteLinkClient objects. Run-time behavior is limited to the state of individual DDESuiteLinkClient objects.After it has been deployed and is operating, a DDESuiteLinkClient object can assume one of several states, which are described in the following table:Related TopicsOverviewConfigurationRun-Time Object AttributesConfigurationThe following section describes the object editor options for configuration and the associated attributes:∙General Configuration∙Topic ConfigurationFor general information on objects, including relationships, deployment, and alarm distribution, see the Integrated Development Environment (IDE) documentation.For information on configuration options for object information, scripts, user-defined attributes (UDAs), or attribute extensions, click Extensions Help in the Help file header.Related TopicsOverviewRun-Time BehaviorRun-Time Object AttributesGeneral ConfigurationUse the General tab to configure the I/O Server from which to retrieve data and to enable alarming for the data connection. For DDE I/O Servers, you can also configure the DDE login.Related TopicsConfigurationTopic ConfigurationUse the Topic tab to specify topics from which the DDESuiteLinkClient object will receive data.Related TopicsConfigurationRun-Time Object AttributesThe following table describes the run-time only attributes for the object.Note Configurable run-time attributes are described in the configuration sections. For more information, see Configuration.For a list of common object attributes, click Extensions Help in the Help file header.Related TopicsOverviewRun-Time BehaviorConfigurationAlarm AttributesIf an alarm attribute is enabled, then the following additional alarm attributes become available. None of these attributes can be alarmed.Related TopicsRun-Time Object Attributes© 2002-2008 Invensys Systems, Inc. All Rights Reserved.11/10/08Object ExtensionsUse object extensions to add functionality to an object while not altering its original behavior. Object extensions are common to all object configuration editors.For more information, click on a Help topic.•O verview•R un-Time Behavior•C onfiguration•R un-Time Object Attributes•M iscellaneous Object AttributesOverviewEach object's editor displays two sets of configuration options: common and custom. The common options are shown on the Object Information, Script, UDA, Extensions and Graphics tabs. The content of the custom tabs is dependent on the object's functionality.Note: Object extensions can be added to derived templates and object instances only. Base templates cannot be extended.All objects in the ArchestrA environment are comprised of a set of attributes that together produce unique functionality. As originally developed, each object's functionality is finite and usable in that state. You may want to increase an object's functionality, and the object extension editor options give you that flexibility. For more detailed information about extending the functionality of an object, see "Working with Object Extensions" in the Integrated Development Environment (IDE) documentation. To access this documentation within the IDE, on the Help menu, click Help Topics.Related TopicsRun-Time BehaviorConfigurationRun-Time Object AttributesRun-Time BehaviorRun-time behavior for an object extension depends on the type of extension being added to the object. Once an extended object is deployed and operating, the following behavior can be expected:Extension BehaviorScript For Startup, On Scan, Off Scan and Shutdown execution types, scripts executewhen those events occur for the object being extended. For the Execute executiontype, the script executes when the Expression, Trigger Type, Trigger Periodand/or Deadband values are satisfied within the context of the object's scanperiod. In other words, scripts cannot be triggered any faster than the scan periodof the engine upon which the script runs.UDA User-defined attributes are passive in nature. They follow the execution order and scan period of the object being extended.Input, Input/Output, Output, Alarm, History, and Boolean label Depending on the data type, existing attributes of an object can be extended by these extensions. They follow the execution order and scan period of the object being extended.See the "Run-Time Behavior" section of the object's custom editor Help file for more information about the run-time behavior of the object being extended. To open custom editor Help, click Configuration Help in the Help file header.Time Propagation for ExtensionsIf the input source supports a time stamp, the value, time stamp and quality (VTQ) is written to the extended attribute. If the input source does not support a time stamp, and if a get failure, data change, or quality change occurs, the value for the extended attribute is time stamped with the current time.If the quality of an output-extended attribute is GOOD or UNCERTAIN, any value change to the extended attribute is forwarded to the destination attribute as it is. If the time stamp changes, the extended attribute's current value and new time stamp is forwarded to the destination attribute.The time stamp of a UDA shows the object startup time when the value is initialized after deployment. The time stamp updates to the current time if a value set request is received with a zero time stamp.The alarm extension uses the extended attribute's time stamp, if available. If the alarm changes state, the TimeAlarmOn or TimeAlarmOff attribute updates to the time stamp of the extended attribute. If the extended attribute does not support time stamps, the TimeAlarmOn or TimeAlarmOff attribute time stamp is based on the current scan time of the hosting AppEngine. If an active alarm is disabled (which forces it to return to normal), the current time is used for the time stamp.The history extension retrieves the value, quality, and time stamp for the attribute and then stores this data to history. If the attribute does not support a time stamp, the current scan time of the hosting AppEngine is used.Advisement of Active Items for ExtensionsIf you configure the object to have input or input/output extensions and advisement of active items is enabled globally, both the reference count and suspend count for the extended attribute is incremented when the object starts up. This puts the object into a suspended state and propagates a suspend message to the input source.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 TopicsOverviewConfigurationRun-Time Object AttributesConfigurationThe following sections describe the common editor configuration options and attributes associated with those options:•O bject Information Configuration•S cript Configuration•U DA Configuration•E xtension Configuration•G raphics ConfigurationFor information about the configuration options on this object's custom tabs, click Configuration Help in the Help file header.Related TopicsOverviewRun-Time BehaviorRun-Time Object AttributesObject Information ConfigurationUse the Object Information tab to:•V iew basic data about the object you are configuring.•C onfigure execution order of the object, relative to other objects. •Provide help for the object you are configuring.EditorOption Associated Attribute Description Run-Time Access (Supervisory , User, Read-Only, None)Description ShortDesc A short textual description of object. Themaximum length is 256 characters.Read-OnlyHierarchica l name HierarchicalName The fully qualified hierarchical name of theobject. For example, "Reactor1.Level."Read-OnlyContainer Container The name of the container that object iscontained in.Read-OnlyCodebase CodeBase The identity of the object's codebase, in theformatVendor.TemplateName.MajorVersionNumber.NoneDerived from (not applicable) Name of the template from which the object(derived template or instance) is derived.NoneHost Host The name of the host to which the object isassigned in the Deployment View. Forexample: for a WinPlatform, it is the Galaxyname; for an AppEngine, it is a WinPlatformname; for an Area, it is an AppEngine name;and for an ApplicationObject, it is an Areaname.Read-OnlyArea Area The name of the area to which the objectbelongs. For top level areas and objects in the"Unassigned" Area, this is not applicable.Read-OnlySecuritygroupSecurityGroup The name of the object's security group. Read-OnlyProcess order ExecutionRelativeOrder Indicates whether the object should runbefore or after another object, or notspecified (None). This option may not beshown for some objects for which executionorder is not allowed.Read-OnlyRelative object ExecutionRelatedObjectIndicates another object that the object runsbefore or after. Unavailable if Process Orderis set to None. Click the browse button toselect an object from the Attribute Browser.Read-OnlyFor detailed information about the default execution order, see "Process Order for AppEngines" in the AppEngine Help file.Related TopicsConfigurationScript ConfigurationUse the Scripts tab to write and configure an executable script associated with the object.Editor Option Associated Attribute Description Run-Time Access (Supervisory, User,Read-Only, None)Script name(not applicable) The name of each script primitiveassociated with the object. Eachattribute is appended to the primitivename for each script.NoneConfigure execution order ScriptOrder An ordinal number indicating within ascript execution group the script'srelative order to other scripts.NoneAliases Aliases, AliasReferences An array of names and their associatedattribute references used in a script orexpression. Aliases = None; AliasReferences = Supervisory, UserDeclarations DeclarationsText A set of valid QuickScript .NETdeclarations using dim.NoneExecution type ScriptExecutionGroup The type of script execution that occursduring object execution: Startup, OnScan, Execute, Off Scan and Shutdown.NoneExpression Expression A string that controls the scriptexecution for all trigger types exceptPeriodic when Execution Type is setto Execute. When the expressionentered meets the trigger condition(While True, On True, On False, DataChange and While False), the script isexecuted. Click the ellipse button toaccess the Attribute Browser.NoneTrigger type TriggerType The function associated with theexpression that together determineswhen the script is executed.Read-OnlyTrigger period TriggerPeriod Indicates the period at which to triggeran Execute type script when TriggerType is set to Periodic. If set to zero(0), the script executes at the scanperiod of the host AppEngine. Thescript always executes at least onceimmediately after going onscan. Thetime format is: days hh:mm:ss.fffffff.Read-OnlyDeadband DataChangeDeadband Only used with Trigger Type DataChange. Specifies the amount theexpression value must change beforethe script is executed.Supervisory, UserRuns asynchronously RunsAsync Sets whether the script is to be runsynchronously (cleared) orasynchronously (checked).Read-OnlyTimeout limit ExecuteTimeout.Limit Indicates the timeout limit, in Read-Onlymilliseconds, for an asynchronous script. (For synchronous scripts, the timeout for the host AppEngine is used.A value of zero (0) disables the timeout. This value is accurate within the resolution of the configured scheduler scan period of the hosting AppEngine.Report alarm on execution error ExecutionError.Alarmed If enabled, an alarm will be triggeredwhen the script engine encounters anerror condition in the script's lastexecution.NonePriority ExecutionError.Priority See Alarm Attributes. Supervisory, UserHistorize script state State.Historized If enabled, the system will historize thestate of the object script.NoneScript box StartupTextOnScanTextExecuteTextOffScanTextShutdownText Displays the script being developed.Must be a valid QuickScript .NETstartup, on scan, execute, off scan or shutdown script. The script is parsedfor language-specific key words, script functions, internal references(referencing attributes of the objectthat the script is assigned to) andexternal references. Syntax errors are raised, including usage of non-existingscript functions.You can access the Script FunctionBrowser and the Attribute Browser by clicking the appropriate button in thescript box toolbar.NoneRelated TopicsConfigurationUDA ConfigurationUse the UDAs tab to add new attributes to the object. A user-defined attribute (UDA) is a holder of data and has no inherent run-time behavior.Every attribute associated with an object exposes the same properties. The following table describes the significant properties you must configure on the UDAs tab.Editor Option AssociatedProperty DescriptionUDA name(not applicable) Name of the UDA attribute associated with the object. Each propertybelow is appended to the attribute name for each UDA.Data type Type Set the attribute's data type: Boolean, Integer, Float, Double, String,Time, Elapsed Time, or InternationalizedString.Category AttributeCategory Set the attribute's category: Calculated, Calculated retentive, Objectwriteable, User writeable. Calculated retentive attributes are savedacross restarts (checkpointed). Note that if you select "Objectwriteable," the security classification is not enabled.This is an array Dimension1 Select if the value of the attribute is an array. Set the array's dimensions in the Number of elements box.Number ofelementsDimension1 The number of elements in the array.--DefaultValue The attribute's default value. The editor interface within the Value groupbox will change based on the data type you have selected, either a checkbox for a Boolean value or a text box for all other data types.Buffered Boolean Determines if the attribute is buffered. If checked, the attribute'shasBuffer property will be true. Buffered attribute supports retrievingand processing of multiple data items which are received from fielddevices during AppEngine’s Scan Period. The purpose of buffered data isto eliminate data folding. Buffered data is used by clients like Alarm,Scripts, and History. An attribute can either be buffered or an array. Related TopicsConfigurationExtension ConfigurationUse the Extensions tab to add new functionality to already existing attributes of the object. These new functionalities include input, output, input-output, alarming, and historization capabilities. This tab displays attributes of the object being configured that can be extended by one or more extensions in the ExtendableAttributes list. When you select an extendable attribute, only the appropriate extensions for that attribute will become available in the Extensions tab.InputOutput ExtensionEditor Option AssociatedAttribute DescriptionRun-TimeAccess(Supervisory,User, Read-Only, None)InputOutput extension (not applicable) Select to add an InputOutput extension to theobject. For more information, see Guidelines forUsing the I/O Extensions.Enabling the InputOutput extension willautomatically disable the Input extension and theOutput extension.NoneSource InputSource The target source from which the value (plusquality) is to be read/written. This attribute alsoidentifies the target destination to which the valueis to be written, if no separate output destination isspecified.Click the ellipse button to access the AttributeBrowser.If changed at run time, the old reference will beunregistered, and the new reference will beregistered. Supervisory, UserOutput destination differs from input source DiffOutputDest Select if the output destination is different from theinput source.NoneDestination OutputDest The target location to which the output value will bewritten. This only applies if the output is to bewritten to a location different from the inputlocation specified by the input source attribute. Ifno value is specified for the output destination (forexample, an empty reference or "---"), then the Supervisory, Userinput and output use the single location specifiedby the input source.Click the ellipse button to access the AttributeBrowser.If changed at run time, the old reference will beunregistered, and the new reference will beregistered. If the new value is not empty or "---",then the reference is not registered. Instead,outputs are to be written through the referencecontained within the mandatory input sourceattribute.Input ExtensionEditor Option AssociatedAttribute DescriptionRun-TimeAccess(Supervisory,User, Read-Only, None)Input extension (notapplicable)Select to add an input extension to the object. Formore information, see Guidelines for Using the I/OExtensions.NoneSource InputSource The target source from which the value (plus quality)is to be read. Click the ellipse button to access theAttribute Browser.If changed at run time, the old reference will beunregistered, and the new reference will beregistered. Supervisory, UserOutput ExtensionEditor Option AssociatedAttribute DescriptionRun-TimeAccess(Supervisory,User, Read-Only, None)Output extension (not applicable) Select to add an output extension to the object. Formore information, see Guidelines for Using the I/ONoneExtensions.Destination OutputDest The target location to which the output value will bewritten. Click the ellipse button to access theAttribute Browser.If changed at run time, the old reference will beunregistered, and the new reference will beregistered. Supervisory, UserOutput every scan OutputEveryScan If selected, the external output is performed everyscan (as long as the extended attribute's quality isGood or Uncertain.).If this check box is cleared, the external output isonly performed when the value changes from thelast successful output, or when the quality changesfrom Bad (or Initializing) to Good (or Uncertain),even if the value has not changed.Supervisory,UserAlarm ExtensionEditor Option AssociatedAttribute DescriptionRun-TimeAccess(Supervisory,User, Read-Only, None)Alarm extension(not applicable) Select to add an alarm extension to theobject.NoneCategory Category See Alarm Attributes. Supervisory,UserPriority Priority See Alarm Attributes. Supervisory,UserAlarm message attribute DescAttrName See Alarm Attributes. Click the ellipsebutton to access the Attribute Browser.NoneActive alarm ActiveAlarmState Indicates the state that triggers a Boolean Nonestate alarm. History ExtensionEditor Option AssociatedAttribute DescriptionRun-TimeAccess(Supervisory,User, Read-Only, None)Historyextension(not applicable) Select to add a history extension to the object. NoneForce storage period ForceStoragePeriod See Historization Attributes. Supervisory,UserEngineering units EngUnits Set the engineering units of the attribute beinghistorized.NoneValue deadband ValueDeadBand See Historization Attributes. Supervisory,UserTrend high TrendHi See Historization Attributes. Supervisory,UserTrend low TrendLo See Historization Attributes. Supervisory,UserDescription Description A brief description for the attribute that is storedto history. You can use descriptive text or areference to another string attribute containingthe history description. If an attribute referenceis used, it must be in the form: "me.AttrName".If you do not provide a description, the objectdescription is used. Supervisory, UserInterpolation Type InterpolationType See Historization Attributes. Supervisory,UserSample Count SampleCount See Historization Attributes. Supervisory,UserRollover Value RolloverValue See Historization Attributes. Supervisory,UserEnable Swinging Door EnableSwingingDoor See Historization Attributes. Supervisory,UserRate DeadBand RateDeadBand See Historization Attributes. Supervisory,UserRelated TopicsConfigurationGuidelines for Using the I/O ExtensionsThree extensions are available for extending an attribute to perform input and/or output: Input, Output, and InputOutput.Note: You cannot reference the same attribute for both the Input extension and the Output extension for a single attribute.Input ExtensionThe Input extension is used to read or copy a value from an external source (for example, a field controller) and place it in an attribute during each scan of the object. Generally, this extension is used only when read functionality is required. If both read and write functionality are required, use an InputOuput extension. Although the Input extension can be used in conjunction with an Output extension, this is only done in the rare case of when you want to read an input from one source, manipulate its value in a script, and send the manipulated value out to a different destination address, all during a single scan of an object. The Input extension runs before any custom scripts or custom logic within the object.InputOutput ExtensionThe InputOutput extension is used to read and write a value from and to an external address (for example, a field controller). The read function is performed every scan. The write function is performed only when the value or quality of the attribute that is extended changes, and the quality is GOOD or UNCERTAIN. This extension is the primary means of achieving a bidirectional connection to an external data source through an extension.The input phase of the InputOutput extension runs before any custom scripts or custom logic within the object. Therefore, scripts can use the current input value for their logic, since that value will be held in the extended attribute.The output change detection logic within the InputOutput extension determines whether to perform an output during a scan. This logic actually occurs prior to reading the value from the source and overwriting the attribute (so that the change request is not lost). If a change in value or quality has occurred, the new value to be written is placed in an attribute named WriteValue. Therefore, you could write a script to examine the extended attribute's WriteValue (as "me.udax.writevalue") and perform validation or clamping on it. The WriteValue attribute is really the value that is "about to be written" when the script executes.。