OPC Studio User's Guide and Reference
UAGlobalApplicationDiscoveryQuery Class
Members 



OpcLabs.EasyOpcUA Assembly > OpcLabs.EasyOpc.UA.Discovery Namespace : UAGlobalApplicationDiscoveryQuery Class
An OPC UA discovery query for searching the applications globally in the administrative domain.
Object Model
UAGlobalApplicationDiscoveryQuery ClassUAEndpointDescriptor ClassUAQueryApplicationsFilter Class
Syntax
'Declaration
 
<CLSCompliantAttribute(True)>
<ComDefaultInterfaceAttribute(OpcLabs.EasyOpc.UA.Discovery.ComTypes._UAGlobalApplicationDiscoveryQuery)>
<ComVisibleAttribute(True)>
<GuidAttribute("8CC79C48-966A-431A-9FF8-A546E7BAB56B")>
<TypeConverterAttribute(System.ComponentModel.ExpandableObjectConverter)>
<ValueControlAttribute("OpcLabs.BaseLib.Forms.Common.ObjectSerializationControl, OpcLabs.BaseLibForms, Version=5.80.82.1, Culture=neutral, PublicKeyToken=6faddca41dacb409", 
   DefaultReadWrite=False, 
   Export=True, 
   PageId=10001)>
<SerializableAttribute()>
Public NotInheritable Class UAGlobalApplicationDiscoveryQuery 
   Inherits UAApplicationDiscoveryQuery
   Implements LINQPad.ICustomMemberProvider, OpcLabs.BaseLib.ComTypes._Info, OpcLabs.BaseLib.ComTypes._Object2, OpcLabs.EasyOpc.UA.Discovery.ComTypes._UAApplicationDiscoveryQuery, OpcLabs.EasyOpc.UA.Discovery.ComTypes._UAGlobalApplicationDiscoveryQuery, System.ICloneable, System.Runtime.Serialization.ISerializable, System.Xml.Serialization.IXmlSerializable 
'Usage
 
Dim instance As UAGlobalApplicationDiscoveryQuery
[CLSCompliant(true)]
[ComDefaultInterface(OpcLabs.EasyOpc.UA.Discovery.ComTypes._UAGlobalApplicationDiscoveryQuery)]
[ComVisible(true)]
[Guid("8CC79C48-966A-431A-9FF8-A546E7BAB56B")]
[TypeConverter(System.ComponentModel.ExpandableObjectConverter)]
[ValueControl("OpcLabs.BaseLib.Forms.Common.ObjectSerializationControl, OpcLabs.BaseLibForms, Version=5.80.82.1, Culture=neutral, PublicKeyToken=6faddca41dacb409", 
   DefaultReadWrite=false, 
   Export=true, 
   PageId=10001)]
[Serializable()]
public sealed class UAGlobalApplicationDiscoveryQuery : UAApplicationDiscoveryQuery, LINQPad.ICustomMemberProvider, OpcLabs.BaseLib.ComTypes._Info, OpcLabs.BaseLib.ComTypes._Object2, OpcLabs.EasyOpc.UA.Discovery.ComTypes._UAApplicationDiscoveryQuery, OpcLabs.EasyOpc.UA.Discovery.ComTypes._UAGlobalApplicationDiscoveryQuery, System.ICloneable, System.Runtime.Serialization.ISerializable, System.Xml.Serialization.IXmlSerializable  
[CLSCompliant(true)]
[ComDefaultInterface(OpcLabs.EasyOpc.UA.Discovery.ComTypes._UAGlobalApplicationDiscoveryQuery)]
[ComVisible(true)]
[Guid("8CC79C48-966A-431A-9FF8-A546E7BAB56B")]
[TypeConverter(System.ComponentModel.ExpandableObjectConverter)]
[ValueControl("OpcLabs.BaseLib.Forms.Common.ObjectSerializationControl, OpcLabs.BaseLibForms, Version=5.80.82.1, Culture=neutral, PublicKeyToken=6faddca41dacb409", 
   DefaultReadWrite=false, 
   Export=true, 
   PageId=10001)]
[Serializable()]
public ref class UAGlobalApplicationDiscoveryQuery sealed : public UAApplicationDiscoveryQuery, LINQPad.ICustomMemberProvider, OpcLabs.BaseLib.ComTypes._Info, OpcLabs.BaseLib.ComTypes._Object2, OpcLabs.EasyOpc.UA.Discovery.ComTypes._UAApplicationDiscoveryQuery, OpcLabs.EasyOpc.UA.Discovery.ComTypes._UAGlobalApplicationDiscoveryQuery, System.ICloneable, System.Runtime.Serialization.ISerializable, System.Xml.Serialization.IXmlSerializable  
Remarks

The query is performed using a QueryServers method on the specified OPC UA Global Discovery Server (GDS).

See also in Knowledge Base: Technical note-OPC UA Discovery in QuickOPC.

 

The various kinds of OPC UA discovery can be generalized into just one method, Discover. This method is given a discovery query argument (of UADiscoveryQuery type) that tells it the requirements for the discovery. The specific kinds of OPC UA discovery described earlier are, in fact, implemented by constructing the discovery query appropriately, and then calling the Discover method.

The UADiscoveryQuery type is an abstract class which is at the root of a structured class hierarchy, with several concrete subclasses:

This generalized discovery mechanism allows for flexibility both on the component and developer sides, and possible future expansion with other kinds of discovery, without a need to introduce new methods into the IEasyUAClient interface.

 

Inheritance Hierarchy

System.Object
   OpcLabs.BaseLib.Object2
      OpcLabs.BaseLib.Info
         OpcLabs.EasyOpc.UA.Discovery.UADiscoveryQuery
            OpcLabs.EasyOpc.UA.Discovery.UAApplicationDiscoveryQuery
               OpcLabs.EasyOpc.UA.Discovery.UAGlobalApplicationDiscoveryQuery

Requirements

Target Platforms: .NET Framework: Windows 10 (selected versions), Windows 11 (selected versions), Windows Server 2016, Windows Server 2022; .NET: Linux, macOS, Microsoft Windows

See Also