QuickOPC User's Guide and Reference
EasyAEClient Class Members
Fields  Properties  Methods  Events


OpcLabs.EasyOpcClassic Assembly > OpcLabs.EasyOpc.AlarmsAndEvents Namespace : EasyAEClient Class

The following tables list the members exposed by EasyAEClient.

Public Constructors
 NameDescription
Public ConstructorOverloaded.   
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Public Fields
 NameDescription
Public FieldDefault value of the Isolated property. Equals to false.  
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Public Properties
 NameDescription
Public Propertystatic (Shared in Visual Basic)Adaptable parameters for non-isolated client objects.  
Public PropertyThe alias provider to be used for resolving aliases by this component.  
Public PropertyCapacity of the callback queue. (Inherited from OpcLabs.BaseLib.Widgets.NotifyingWidget)
Public PropertyThe idle time before the internal thread executing the queued callbacks is stopped. (Inherited from OpcLabs.BaseLib.Widgets.NotifyingWidget)
Public Property (Inherited from System.ComponentModel.Component)
Public PropertyCan be used to distinguish otherwise equal widgets. (Inherited from OpcLabs.BaseLib.Widgets.Widget)
Public PropertyContains parameters that influence the behavior of just this instance of the component.  
Public PropertySpecifies that you wish that the EasyAEClient object instance works with an "isolated" connection to the OPC server, i.e. one that is not shared with other instances.  
Public PropertyContains parameters that influence the behavior of the component when it is isolated.  
Public PropertyProvides dictionary of license data fields and their values.  
Public PropertyCapacity of the event pull queue for notifications.  
Public PropertyDetermines whether the component will deliver all callbacks in a queued manner. (Inherited from OpcLabs.BaseLib.Widgets.NotifyingWidget)
Public Propertystatic (Shared in Visual Basic)A default, shared instance of the client object.  
Public Propertystatic (Shared in Visual Basic)Parameters that are always shared by all instances of the component.  
Public Propertystatic (Shared in Visual Basic)Container for services that are shared by all instances of the component.  
Public Propertystatic (Shared in Visual Basic)Provides services that are shared by all instances of the component.  
Public Property (Inherited from System.ComponentModel.Component)
Public PropertyGets the OPC technologies supported.  
Public PropertyContains synchronization context used by the object when performing asynchronous operations (including event notifications). (Inherited from OpcLabs.BaseLib.Widgets.NotifyingWidget)
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Protected Properties
 NameDescription
Protected Property (Inherited from System.ComponentModel.Component)
Protected Property (Inherited from System.ComponentModel.Component)
Protected Property (Inherited from System.ComponentModel.Component)
Protected PropertyThe service container provided by this widget to inheritors. (Inherited from OpcLabs.BaseLib.Widgets.Widget)
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Public Methods
 NameDescription
Public MethodOverloaded. Acknowledges a condition in the Event Server. Uses server descriptor for specifying the OPC server. Use default acknowledger ID and an empty comment.  
Public MethodBrowses the specified area (or root) in OPC server's process area space, and returns information about child nodes (areas or sources) found. Uses server descriptor for specifying the OPC server. A parent area descriptor is passed in. No vendor-specific filtering.  
Public MethodBrowses the specified computer and returns information about OPC (Alarms and Events) servers found.  
Public Method

Changes parameters of a particular event subscription.

Changes parameters of an event subscription. Specify new notification rate, subscription filter object, and an "active" flag.

 
Public MethodOverridden.   
Public Methodstatic (Shared in Visual Basic)Creates a new instance of the class.  
Public MethodCreates an object that contains all the relevant information required to generate a proxy used to communicate with a remote object. (Inherited from System.MarshalByRefObject)
Public MethodOverloaded. Overridden. Clean up any resources being used.  
Public Method (Inherited from object)
Public MethodReturns the current state information for the condition instance corresponding to the source and condition name, passing in a server descriptor. Also allows to retrieve specified event attributes.  
Public MethodObtains parameters of specified events subscription.  
Public MethodServes as the default hash function. (Inherited from object)
Public MethodRetrieves the current lifetime service object that controls the lifetime policy for this instance. (Inherited from System.MarshalByRefObject)
Public MethodOverridden.   
Public Method (Inherited from OpcLabs.BaseLib.Widgets.Widget)
Public MethodOverridden.   
Public MethodGets the System.Type of the current instance. (Inherited from object)
Public MethodObtains a lifetime service object to control the lifetime policy for this instance. (Inherited from System.MarshalByRefObject)
Public MethodDetermines whether the given event subscription handle is known to this client.  
Public MethodAttempts to pull multiple OPC events subscribed to by the IEasyAEClient.SubscribeEvents method. Returns refresh or standard event notifications.  
Public Method

Finds out events categories supported by the server.

The QueryEventCategories method gives clients a means of finding out the specific categories of events supported by a given server. This method would typically be invoked prior to specifying an event filter. Servers are able to define their own custom event categories, but a list of recommended categories is provided in the OPC specification.

Server descriptor is used for specifying the OPC server. Queries event categories for given event types.

 
Public MethodFinds out event conditions associated with the specified source name. Uses server descriptor for specifying the OPC server.  
Public MethodRaises a callback or event using a given handler and passing it specified event arguments, optionally specifying whether to enqueue the call. (Inherited from OpcLabs.BaseLib.Widgets.NotifyingWidget)
Public Method (Inherited from OpcLabs.BaseLib.Widgets.Widget)
Public MethodForce a refresh for all active conditions and inactive, unacknowledged conditions whose event notifications match the filter of the event subscription.

Clients often need to get the current condition information from the server, particularly at client startup, for things such as a current alarm summary. The OPC Event Server supports this requirement by resending the most recent event notifications which satisfy the filter in the event subscription and which are related to active and/or unacknowledged conditions. The client can then derive the current condition status from the "refreshed" event notifications.  
Public MethodSets the object properties back to their defaults.  
Public Method

Subscribe to particular OPC events. The IEasyAEClient.Notification is generated for each event.

Subscribe to particular OPC events, using an object that holds all necessary arguments.

 
Public MethodOverridden. Returns a string that represents the current object.  
Public MethodUnsubscribe from changes of all OPC events.  
Public MethodUnsubscribe from particular OPC event notifications.  
Public MethodOverloaded. Determines whether the specified EasyAEClient is value equal to the current object.  
Public Method (Inherited from OpcLabs.BaseLib.Widgets.Widget)
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Protected Methods
 NameDescription
Protected MethodOverridden. Processes an error that has occurred during a callback. Processes an error that has occurred during a callback.  
Protected Method (Inherited from System.ComponentModel.Component)
Protected MethodOverloaded. Creates a shallow copy of the current System.MarshalByRefObject object. (Inherited from System.MarshalByRefObject)
Protected MethodOverridden. Infrastructure. Infrastructure.  
Protected MethodOverridden. Infrastructure. Infrastructure.  
Protected MethodInfrastructure. (Inherited from OpcLabs.BaseLib.Widgets.Widget)
Protected MethodOverridden. Infrastructure. Infrastructure.  
Protected MethodOverridden. Processes an error that has occurred during sending of a callback. Processes an error that has occurred during a callback.  
Protected MethodOverloaded. Invokes the specified action in a synchronized manner. (Inherited from OpcLabs.BaseLib.Widgets.NotifyingWidget)
Protected MethodOverridden. Infrastructure. Infrastructure.  
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Extension Methods
 NameDescription
Public Extension MethodOverloaded. Acknowledges a condition in the Event Server. The client will receive event notifications (indicating the acknowledgement) from conditions. This method specifically acknowledges the condition becoming active or transitioning into a different sub-condition (and no other state transition of the condition). One or more conditions belong to a specific event source - the source of the event notification. For each condition-related event notification, the corresponding Source, Condition Name, Active Time and Cookie is received by the client as part of the event notification.

The server can be local or can be remotely accessed via DCOM. Optionally, an access path can be specified or a specific data type can be requested.

The client is required to pass the activeTime and cookie received in the event notification to the AcknowledgeCondition method without modification.

Public Extension MethodAcknowledges multiple conditions in the Event Server.
Public Extension MethodOverloaded. Browses the specified area (or root) in OPC server's process area space, and returns information about child areas found.
Public Extension MethodOverloaded. Browses the specified area (or root) in OPC server's process area space, and returns information about child nodes (areas or sources) found.
Public Extension Method

Browses the nodes in OPC A&E server's address space. Starts from the specified node, and returns information about child nodes found.

Browses the nodes in server's address space, given a browse arguments object.

Public Extension MethodOverloaded. Browses for OPC (Alarms&Events) servers.
Public Extension MethodOverloaded. Browses the specified area (or root) in OPC server's process area space, and returns information about child sources found.
Public Extension MethodOverloaded. Allows to traverse through OPC A&E address space nodes under the specified node, using given browse arguments.
Public Extension MethodOverloaded. Changes parameters of a particular event subscription.
Public Extension MethodAttempts to find a specified event category in the OPC server, and returns information about it when found.
Public Extension MethodAttempts to find a specified event condition in the OPC server and for given event category, and returns information about it when found.
Public Extension MethodOverloaded. Returns the current state information for the condition instance corresponding to the source and condition name.

The server can be local or can be remotely accessed via DCOM. Optionally, an access path can be specified or a specific data type can be requested.

Some servers may not maintain sufficient condition state information to fully implement this method.

Public Extension MethodAttempts to pull an OPC event subscribed to by the IEasyAEClient.SubscribeEvents method. Returns refresh or standard event notifications.
Public Extension MethodOverloaded. Finds out event attributes that the server can provide as part of an event notification within a given event category. Uses server descriptor for specifying the OPC server.
Public Extension MethodOverloaded. Finds out event conditions supported by given event category. Uses server descriptor for specifying the OPC server.
Public Extension MethodOverloaded. The QueryEventCategories method gives clients a means of finding out the specific categories of events supported by a given server. This method would typically be invoked prior to specifying an event filter. Servers are able to define their own custom event categories, but a list of recommended categories is provided in the OPC specification.
Public Extension MethodFinds out event conditions associated with the specified source name. Computer name and server class are used for specifying the OPC server.
Public Extension MethodOverloaded. Subscribe to particular OPC events. The IEasyAEClient.Notification is generated for each event.
Public Extension MethodOverloaded. The size of the input array will become the size of the output array. The element positions (indices) in the output array are the same as in the input array. The function returns an array of integer handles. Each such handle uniquely identifies the events subscription. The indices of elements in the output array are the same as those in the input array.
Public Extension MethodDetermines whether the client object supports a given OPC technology or technologies (such as OPC COM or OPC XML).
Public Extension Method

Unsubscribe from changes of multiple OPC events.

Unsubscribe from changes of multiple OPC events, specifying array of integer handles.

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Public Events
 NameDescription
Public Event (Inherited from System.ComponentModel.Component)
Public EventRaised when a failure in the eventing infrastructure occurs.  
Public EventRaised for loggable entries originating in the OPC-A&E client engine and the EasyAEClient component.  
Public EventRaised for every OPC event subscribed to by the SubscribeEvents method. This method can be called whether this is a refresh or standard event notification.  
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See Also

Reference

EasyAEClient Class
OpcLabs.EasyOpc.AlarmsAndEvents Namespace