OPC Studio User's Guide and Reference
OpcLabs.EasyOpc.UA.Discovery Namespace
Inheritance Hierarchy
OpcLabs.EasyOpcUA Assembly : OpcLabs.EasyOpc.UA.Discovery Namespace
This namespace contains classes for OPC Unified Architecture (OPC-UA) discovery.
Classes
 ClassDescription
ClassContains OPC UA application description.
ClassSpecifies an OPC UA application discovery query.
ClassContains OPC UA application registration information.
ClassContains utility methods for the UAApplicationTypes class.
ClassContains information gathered about an OPC application (typically, an OPC-UA server) or an endpoint.
ClassA collection of application elements (servers, UADiscoveryElement).
ClassSpecifies a discovery query in OPC Unified Architecture.
ClassAn OPC UA discovery query for searching the applications globally in the administrative domain.
ClassSpecifies an OPC UA discovery query performed using a LDS or LDS-ME service.
ClassAn OPC UA discovery query for applications on the specified discovery host or discovery endpoints.
ClassAn OPC UA discovery query for local endpoints.
ClassAn OPC UA discovery query for applications on a network.
ClassA filter used to find servers that meet the specified criteria.
ClassA DNS service record for OPC Unified Architecture (OPC UA).
Interfaces
 InterfaceDescription
InterfaceContains read-only OPC UA application registration information.
InterfaceContains read-only information gathered about an OPC application (typically, an OPC-UA server) or an endpoint.
Enumerations
 EnumerationDescription
EnumerationThe type of application.
Remarks

 

OPC UA Discovery allows OPC Data Client to find available OPC UA servers, and determine how to make connections to them. There are several approaches to discovery, and they can be combined together to achieve the desired functionality. Clients and servers can be on the same host, on different hosts in the same subnet, or even on completely different locations in an administrative domain.

OPC Data Client provides following kinds of discovery:

It is also possible to access the discovery functionality in a common way, using Generalized OPC UA Discovery.

Flattened and unflattened results

By default, the results (the application element collection) of many of the methods described in this chapter are returned flattened. This means that a single OPC UA application may appear multiple times in the resulting collection, and each time it will have precisely one DiscoveryUriString associated with it.

Alternatively, you can use method overloads with the additional 'flat' argument, and set it true, in order to receive unflattened result. In this case, each OPC UA application will be contained just once in the resulting collection, but it may have one or more discovery URL in its DiscoveryUriStrings property. In this case, do not use the DiscoveryUriString property, because it will contain an empty string if the application has more than one discovery URL.

Alarms & Conditions

Please refer to the “Discovering OPC UA Servers” chapter under “Imperative Programming Model for OPC Data (Class and UA)” for all necessary information. OPC Unified Architecture, as the name suggests, allows to treat multiple functionality areas commonly, and the same OPC Servers that provide Data Access functionality are (or can be) also Alarms & Conditions servers.

 

See Also

Reference

OpcLabs.EasyOpcUA Assembly