Reference

Upgrade to a new version

This page lists all changes that can affect existing code when you upgrade to a newer version of the OPC UA .NET SDK: changed interfaces and behavior, renamings, and new requirements. Select the version you use today and the version you upgrade to. The list then shows the changes in between, in the order in which they were added.

The entries come from the Version history. The version number above each section leads to the complete release notes of that version, including new features and fixes.

From version1.01.41.51.62.02.12.22.32.52.62.72.82.92.102.112.122.132.142.152.162.172.182.192.202.212.222.232.242.252.262.272.282.292.302.312.322.332.402.412.422.502.512.522.532.542.552.562.572.582.59To version1.01.41.51.62.02.12.22.32.52.62.72.82.92.102.112.122.132.142.152.162.172.182.192.202.212.222.232.242.252.262.272.282.292.302.312.322.332.402.412.422.502.512.522.532.542.552.562.572.582.59195 changes

1.5

• Changed1.5.5.0
  Moved the Identity and ImpersonationContext classes from the Opc.UaFx.Server to the Opc.UaFx namespace.
• Changed1.5.6.7
  The OpcValueLabel is now no longer defined as a struct; instead it is now a class.

1.6

• Changed1.6.5.2
  Removed implicit interpretation of a numeric node identifier encoded as a string.

2.2

• Changed2.2.2.0
  Simplified OpcValue.ToString implementation to just provide null for null references or the Value.ToString().

2.3

• Changed2.3.0.0
  The SDK no longer supports Windows-based authentication using the WinLogon API for OPC UA server authentication.
• Changed2.3.0.0
  Application certificates are now created using SHA256 (the default defined by the Foundation). This does not influence any running code. This change will only have an effect when a new certificate is generated.
• Attention2.3.1.0
  Starting with this version, a reference to the NuGet package Portable.BouncyCastle (at least version 1.8.1.3) or the BouncyCastle.Crypto assembly (at least version 1.8.1.146) is required.
• Attention2.3.1.0
  Using a server address with the scheme https requires references to the NuGet packages Microsoft.AspNetCore.Server.Kestrel (1.1.3) and Microsoft.AspNetCore.Server.Kestrel.Https (1.1.3).
• Changed2.3.2.0
  OpcVariableNode defined as an abstract base class.
• Changed2.3.2.0
  Removed multiple local Foundation node references to reduce memory usage.

2.5

• Changed2.5.0.0
  Corrected misspelled members.
• Changed2.5.0.0
  Streamlined API through additional descriptive parts in class and delegate names. In general, changed the naming of Data to DataSet, DataItem to DataSetItem and EventRaise to Event.
• Changed2.5.0.0
  OpcNodeId.ToString now formats by default using the OpcNodeIdFormat.Foundation format.
• Changed2.5.0.0
  Order of subscription events from MonitoredItem → Client → Subscription to MonitoredItem → Subscription → Client, to ensure a more logical event order using bubbling.
• Changed2.5.0.0
  Renamed OpcMonitoredItem.ReceivedDataChange to OpcMonitoredItem.DataChangeReceived.
• Changed2.5.0.0
  Renamed OpcMonitoredItem.ReceivedEventRaise to OpcMonitoredItem.EventRaiseReceived.
• Renamed2.5.0.0
  OpcSubscribeEventRaise -> OpcSubscribeEvent
• Renamed2.5.0.0
  OpcDataChangeEventArgs -> OpcDataChangeReceivedEventArgs
• Renamed2.5.0.0
  OpcDataChangeEventHandler -> OpcDataChangeReceivedEventHandler
• Renamed2.5.0.0
  OpcEventRaiseEventArgs -> OpcEventReceivedEventArgs
• Renamed2.5.0.0
  OpcEventRaiseEventHandler -> OpcEventReceivedEventHandler
• Renamed2.5.0.0
  OpcNotificationEventArgs -> OpcNotificationReceivedEventArgs
• Renamed2.5.0.0
  OpcNotificationEventHandler -> OpcNotificationReceivedEventHandler
• Renamed2.5.0.0
  OpcDataChangeCallback -> OpcDataChangeReceivedCallback
• Renamed2.5.0.0
  OpcEventRaiseCallback -> OpcEventReceivedCallback
• Renamed2.5.0.0
  IOpcNotificationData -> IOpcNotificationDataSet
• Renamed2.5.0.0
  OpcNotificationData -> OpcNotificationDataSet
• Renamed2.5.0.0
  OpcNotificationDataCollection -> OpcNotificationDataSetCollection
• Renamed2.5.0.0
  OpcNotificationDataReadOnlyCollection -> OpcNotificationDataSetReadOnlyCollection
• Renamed2.5.0.0
  OpcNotificationDataItem -> OpcNotificationDataSetItem
• Renamed2.5.0.0
  OpcNotificationDataItemCollection -> OpcNotificationDataSetItemCollection
• Renamed2.5.0.0
  OpcNotificationDataItemReadOnlyCollection -> OpcNotificationDataSetItemReadOnlyCollection
• Renamed2.5.0.0
  OpcDataChange -> OpcDataChangeSet
• Renamed2.5.0.0
  OpcDataChangeItem -> OpcDataChangeSetItem
• Renamed2.5.0.0
  OpcEventRaise -> OpcEventDataSet
• Renamed2.5.0.0
  OpcEventRaiseItem -> OpcEventDataSetItem
• Renamed2.5.0.0
  OpcMonitoredItem

  • .EventRaiseReceived -> EventReceived
  • .LastEventRaise -> LastEvent
  • .OnEventRaiseReceived -> OnEventReceived
• Renamed2.5.0.0
  OpcSubscription

  • .EventRaiseReceived -> EventReceived
  • .ReceivedEventRaiseCallback -> ReceivedEventCallback
  • .OnEventRaiseReceived -> OnEventReceived
• Renamed2.5.0.0
  OpcClient

  • .EventRaiseReceived -> EventReceived
  • .OnEventRaiseReceived -> OnEventReceived
  • .SubscribeEventRaise -> SubscribeEvent
• Changed2.5.0.1
  Downgraded sample projects to C# language version 6.0 to ensure that the samples will compile in older versions of Visual Studio.
• Changed2.5.1.0
  Changed IsNodeAccessible(..., IOpcNode node) to IsNodeAccessible(..., IOpcNodeInfo node).
• Changed2.5.4.0
  OpcNode.BeforeApplyChanges and OpcNode.AfterApplyChanges are now only raised if changes are pending (see OpcNode.HasPendingChanges).
• Changed2.5.5.0
  Changed default MinimumCertificateKeySize from 2048 to 1024 to support lower key sizes used by older certificates.
• Changed2.5.5.0
  When changing the application certificate of a client or server instance using the Certificate property, the store path type of the application certificate store changes to System. To use the store path type Directory, you have to change the store path type manually and have to ensure that the certificate can be found in the application certificate store after changing the Certificate property.
• Changed2.5.7.0
  The application certificate is no longer stored in .\CertificateStores\Trusted, now it is stored (by default) in .\CertificateStores\App to improve startup performance when searching for the application certificate.
• Changed2.5.7.0
  Changed use of LinkTime to LastWriteTime of the assembly when determining OpcServerInfo from an assembly.

2.6

• Changed2.6.0.0
  Removed OpcClientTransport class (replaced by new OpcTransport class).
• Changed2.6.0.0
  Removed OpcServerTransport class (replaced by new OpcTransport class).
• Changed2.6.0.0
  The default server information provided by OpcServerBase now prefers a predefined ApplicationName.
• Changed2.6.0.0
  OpcSecurityPolicyCollection no longer provides a constructor with an OpcServerBase instance. The corresponding Owner property has been removed as well.

2.7

• Changed2.7.0.0
  Removed OpcServerIdentity.Password property, because there is no need to publish the internally stored password information and it is not a good practice to provide references to an array through properties.
• Changed2.7.0.0
  Removed OpcTransformUserPasswordDelegate delegate.
• Changed2.7.0.0
  Replaced OpcUserNameAcl.PasswordTransform with virtual Matches and TransformPassword methods in OpcServerIdentity.
• Changed2.7.3.0
  Reviewed implementation of OpcMonitoredItem and OpcSubscription: Changed some int-based properties to use long as the property type to support underlying uint properties used by the foundation stack in a CLSCompliant way.
• Changed2.7.4.0
  Changed some int-based properties in OpcMonitoredItem, OpcServiceCounter, OpcSessionDiagnostics and OpcServerDiagnostics to long as their property type to assure CLS compliance while accessing the unsigned API of the foundation stack.
• Changed2.7.5.0
  OpcMonitoredItem.AutoFlushCache has been replaced with the new OpcMonitoredItem.QueueMode property to better express the mechanism used when the notification data item queue of a MonitoredItem overflows.

2.8

• Changed2.8.0.0
  OpcDataTypeAttribute is now applicable on classes and structures.
• Changed2.8.0.0
  Unified OpcNodeManager.NamespaceIndexes and OpcNodeManager.NamespaceUris into new OpcNodeManager.Namespaces.
• Changed2.8.0.0
  Renamed IOpcReadOnlyDataStore to IOpcReadOnlyNodeDataStore.
• Changed2.8.0.0
  IOpcNamespaceResolver methods Uri Resolve(int namespaceIndex) and int Resolve(Uri namespaceUri) are now obsolete.
• Changed2.8.1.0
  OpcAutomatism.UseDynamic property default value is now false. Change its value or the OpcClient.UseDynamic to true to enable use of OpcDataObject.
• Changed2.8.1.2
  Adjusted iconUrl and licenseUrl information in NuGet packages upon their deprecation.
• Changed2.8.2.0
  Explicitly encoded information known as the EncodingMask of a structured data type is now handled using the new Opc.UaFx.Bit type instead of System.Boolean.
• Changed2.8.3.0
  Reviewed OpcClient.State changes to detect a lost connection to the server.
• Changed2.8.3.0
  OpcClient.State now changes automatically only to Disconnected (during a running request) if ReconnectTimeout is greater than zero (reconnection is manually handled).

2.9

• Changed2.9.0.0
  License codes used prior to version 2.9 no longer work. Customers will receive new license keys working in all frameworks supported.
• Changed2.9.0.0
  OpcAttributeWriteAccess is now based on UInt32.
• Changed2.9.0.0
  The default value of OpcAutomatism.AlwaysParseStringIdentifiers is now false. As a result, the value is no longer parsed automatically when the constructor OpcNodeId(string) is called. For more details, see OpcAutomatism.AlwaysParseStringIdentifiers.
• Changed2.9.0.0
  [Client SDK] Moved the OpcBrowseNode class from namespace Opc.UaFx.Client to namespace Opc.UaFx.
• Changed2.9.0.0
  [Client SDK] Moved the OpcBrowseNodeDegree enumeration from namespace Opc.UaFx.Client to namespace Opc.UaFx.
• Changed2.9.0.0
  [Client SDK] IOpcBrowseService and OpcBrowseRequest now use the classes OpcViewDescription and OpcBrowseNode instead of the Foundation classes ViewDescription and BrowseDescription.
• Changed2.9.0.0
  Moved OpcReadOnlyNamespaceCollection from namespace Opc.UaFx.Server to namespace Opc.UaFx.
• Changed2.9.0.0
  Changed the default value of the DataType attribute of OpcDataTypeDictionaryNode from Byte to ByteString to match the definition of the specification.
• Changed2.9.0.0
  Renamed Description property of IOpcDataTypeInfo, OpcDataTypeInfo and OpcDataFieldInfo to Documentation to match the definition of the OPC UA specification.
• Changed2.9.0.0
  OpcEncoding.All(...) now constructs the OpcEncoding.Id using the default BrowseNames for the different encoding types.
• Changed2.9.0.0
  OpcNamespace.ToString() now always returns a string which just represents the OpcNamespace.Value and OpcNamespace.Index (if not zero).
• Changed2.9.0.0
  OpcNodeSet.GetDataTypeSystem() now provides an OpcDataTypeSystem instance which uses the typical BrowseName for the type of encoding used by the type system.
• Changed2.9.0.0
  Removed method IOpcTypeProvider.GetType(OpcEncoding), because encoding information only applies to data types.
• Changed2.9.0.0
  OpcTypeCategory.EventType and OpcTypeCategory.ReferenceType have been removed.

2.10

• Changed2.10.0.0
  OpcNode.OnAfterApplyChanges and OpcNode.OnBeforeApplyChanges use OpcNodeChangesEventArgs instead of EventArgs.
• Changed2.10.0.0
  OpcNode.AfterApplyChanges and OpcNode.BeforeApplyChanges pass OpcNodeChangesEventArgs instead of EventArgs to event handlers.

2.11

• Changed2.11.0.0
  OpcSession.Close closes the session and invalidates the session-related identifier.
• Changed2.11.0.0
  OpcClient methods validate the connection state using an OpcException (with BadServerNotConnected) instead of using an InvalidOperationException.
• Changed2.11.0.0
  Default QueueSize of OpcMonitoredItem created using OpcClient.SubscribeEvent(s) from int.MaxValue to uint.MaxValue to enforce that the server uses the maximum queue size supported for event notifications (which was initially intended with the wrong int.MaxValue).
• Changed2.11.0.0
  Renamed OpcMonitoredItemStatus.DataItemQueueSize to QueueSize to match the naming used in OpcMonitoredItem (which defines the requested size while the status gives the revised size).
• Changed2.11.0.0
  Returned type of OpcMonitoredItemStatus.Id from Int32 to Int64 to cover the underlying non-CLS compliant UInt32 of the Foundation's stack.
• Changed2.11.0.0
  Adopted recently reviewed API of OpcMonitoredItem to OpcMonitoredItemStatus and reworked OpcMonitoredItemStatus.AutoFlushCache to QueueMode (as in OpcMonitoredItem).
• Changed2.11.1.0
  The constructor of OpcCertificateJudgementEventArgs no longer verifies if the specified certificates are a null reference (Nothing in Visual Basic), because some servers might supply no certificate data for endpoints with the policy None (mode and algorithm).
• Changed2.11.3.0
  Used data type in OpcNode.Read/WriteDescriptionCallback property from String to OpcText.
• Changed2.11.3.0
  OpcDataChangeDataSetItem.ClientID from Int32 to Int64 to match the used type in OpcMonitoredItem.ClientID.

2.12

• Changed2.12.0.0
  The OpcNamespace.Default namespace now provides the default value and URI used to identify the Foundation's default namespace.
• Changed2.12.0.0
  Removed obsolete methods from IOpcNamespaceResolver and all its implementations in OpcClient, OpcServer, OpcContext and OpcNodeManager.
• Changed2.12.0.0
  OpcClient.State no longer transitions (using the reconnect mechanism activated by default) when calling, for example, ReadNode while the OpcClient is about to re-establish a broken connection.
• Changed2.12.0.0
  In case of a broken connection, the OpcClient tries (by default) to re-establish the connection and re-use the previously used session. If this works, the OpcClient will raise the Reconnected event as before. If the client has been forced to create a new session (for example, upon timeout of the previous session), the OpcClient will now raise the Connected event instead of the Reconnected event to provide a way to distinguish these conditions in user code.
• Changed2.12.0.0
  Comparison in OpcNodeId and OpcNamespace to provide results typically used by .NET APIs when comparing to a null reference (this differs from the implementation used by the Foundation).
• Changed2.12.1.0
  Bidirectional references between DataTypeDescription, DataTypeEncoding and DataType nodes are now unidirectional (using default export options).

2.14

• Changed2.14.0.0
  Removed duplicate references to DataTypeNodes when using the OpcAddressSpace class to describe the nodes of the server.

2.18

• Changed2.18.0.0
  Format of ByteString from Base64 encoding to hex (X2) encoded / formatted strings, which matches the Foundation's binary encoded representation of a ByteString.
• Changed2.18.2.0
  OpcNodeId now matches the OPC UA specification and compares node identifiers and namespaces case-sensitively.
• Changed2.18.3.0
  OpcClassicDiscoveryClient now uses OpcException to represent all stack related exceptions.

2.19

• Breaking2.19.0.0
  Clients and servers since version 2.17.0.0 do not access or provide file nodes according to the OPC UA specification. They use a byte array instead of ByteString to read and write file contents. This issue has been fixed in this version.
• Breaking2.19.0.0
  OpcFileReadMethodNode.FileReadCallback and OpcFileReadMethodNode.FileReadExCallback now return a ByteString instead of an array of bytes.
• Breaking2.19.0.0
  OpcFileWriteMethodNode.FileWriteCallback and OpcFileWriteMethodNode.FileWriteExCallback now accept a ByteString for the data parameter instead of an array of bytes.
• Changed2.19.0.0
  Parameter of OpcFilterOperand.OfType from value : object to typeId : OpcNodeId to assure that an OfType operand is evaluated as expected (that is, using an OpcNodeId).
• Breaking2.19.0.0
  Regression issue using OpcFileNode access using Read and Write operations after enforcing the Foundation's stack to use ByteString for ByteString and Byte[] for Byte[] instead of using ByteString for Byte[].
• Breaking2.19.1.0
  Possibly breaking: IOpcReadOnlyNodeDataStore now requires the implementation of IOpcNamespaceResolver as well.
• Changed2.19.2.0
  Removed unnecessary new lines in the string representation of OpcException instances.

2.20

• Changed2.20.0.0
  OpcInstanceNode now determines its DefaultTypeDefinitionId using the node type used to create the instance node.
• Changed2.20.0.0
  OpcMemberOrigins now defines an additional enum member Method for method origins.

2.24

• Changed2.24.0.0
  The OpcNodeAccessToken.IndexRange is now obsolete, use new OpcNodeAccessToken.Range property instead.
• Changed2.24.0.0
  The property type of OpcReadVariableValueContext(<T>).Range has been changed from Ua.NumericRange to OpcRange.
• Changed2.24.0.0
  The property type of OpcWriteVariableValueContext(<T>).Range has been changed from Ua.NumericRange to OpcRange.
• Changed2.24.0.0
  The property type of OpcReadPropertyValueContext(<T>).Range has been changed from Ua.NumericRange to OpcRange.
• Changed2.24.0.0
  The property type of OpcWritePropertyValueContext(<T>).Range has been changed from Ua.NumericRange to OpcRange.

2.25

• Changed2.25.0.0
  Default size of (auto) encoding mask from one bit to 32 bit to improve usability of the by default expected 32 bit encoding mask.

2.28

• Changed2.28.0.0
  Disabling OpcAutomatism.UseDynamicTypeRegistration resulted in a deferred dynamic type registration at the time a custom data type is manually registered.

2.29

• Changed2.29.0.0
  OpcNode.AddNotifier is no longer supported on other types than OpcObjectNodes and their subclasses.

2.30

• Changed2.30.0.0
  The behavior of starting and stopping an OPC Classic UA Wrapper Server is now more deterministic, as each OpcClient uses a dedicated wrapper server, which is now also stopped when the OpcClient disconnects.
• Changed2.30.0.0
  The method OpcCertificateIdentity.Matches() is now virtual to enable custom identity comparison.
• Changed2.30.0.0
  The OpcEvent.EventId property now provides the underlying ByteString instead of a byte-array (before the ByteString was introduced).

2.31

• Changed2.31.0.0
  Updated Newtonsoft.Json dependency to version 13.0.3, to fix a vulnerability.
• Changed2.31.0.0
  The UA Wrapper Server for OPC Classic connections will now always generate a new application certificate, instead of trying to load one from the client's certificate store.
• Changed2.31.0.0
  When no port is specified on an opc.com: URL, the port for the classic wrapper server is no longer derived from the classID and progID, but instead a free dynamic port number is determined. This facilitates using multiple OpcClients with the same opc.com: URL at the same time.

2.33

• Changed2.33.0.0
  OpcContext.Empty.SessionId no longer provides a null reference (Nothing in Visual Basic). Instead it provides OpcNodeId.Null.
• Changed2.33.0.0
  Changed access modifiers of OpcNodeManager.AddNode(...) and OpcNodeManager.RemoveNode(...) methods from protected to public for improved usability.
• Changed2.33.0.0
  Evaluation of OpcVariableNodeInfo.IsArray now uses the ValueRank value instead of the ArrayDimensions to decide whether the Value attribute provides an array.

2.41

• Changed2.41.0.0
  User authentication in the OpcServer is now done only once during ActivateSession, instead of doing it for each request separately.
• Changed2.41.1.0
  Updated Microsoft.AspNetCore.Server.Kestrel.Core dependency to version 2.1.25, to fix a vulnerability.

2.42

• Changed2.42.0.0
  OpcArgument.ArrayDimensions and OpcArgumentInfo.ArrayDimensions now support null references (Nothing in Visual Basic) when enabled via OpcAutomatism.UseNullInsteadOfEmptyArrays. This means whenever a server provides a value of null for the ArrayDimensions this property will now return a null reference (Nothing in Visual Basic) as well.
• Changed2.42.4.0
  Updated Portable.BouncyCastle dependency to version 1.9.0, to fix a vulnerability.

2.50

• Changed2.50.0.0
  When OpcClientSecurity.UseOnlySecureEndpoints is set to true, the OpcClient now only selects endpoints with a SignAndEncrypt mode, and no longer selects ones with a Sign mode, because the latter does not provide confidentiality. To use the previous behavior of selecting endpoints with a Sign or SignAndEncrypt policy, set client.Security.EndpointPolicy to one with that mode, and set OpcClient.Security.AutoUpgradeEndpointPolicy to true. Alternatively, to select the "best" endpoint offered by the server, set OpcClient.Security.UseHighLevelEndpoint to true (but note that this does not provide security).
• Changed2.50.0.0
  When creating an event filter with OpcEventFilterFactory.Select(), the type identifier of the BaseEventType is now used by default in the simple attribute operands (as it was before version 2.32.0.0), to ensure that when specifying multiple event types that may have fields with the same name, all fields can be received. To use the previous behavior of specifying the actual event type identifier in the simple attribute operands, specify OpcEventFieldSelectOptions.UseExplicitEventTypeIds in OpcEventFilterFactory.Select().
• Changed2.50.4.0
  Wrong DefaultReferenceTypeId Organizes of OpcFolderNode and adopted use of HasComponent instead. This change addresses CTT compliance.
• Changed2.50.4.0
  ServerDiagnostics no longer provides children and any explicit read/write operations on the child nodes using their NodeId result in BadOutOfService. This behavior applies for disabled ServerDiagnostics and addresses CTT compliance.
• Changed2.50.5.0
  Reworked request validation to validate first the contents of the request and then validate if the operation requested is granted. In addition, any diagnostics (including null references) are provided only if requested. This addresses CTT compliance.
• Changed2.50.6.0
  Moved Model property and all other OpcNodeModel related API from OpcInstanceNode to OpcNode to ensure correct node initialization.
• Changed2.50.7.0
  Improved CTT compliance regarding OpcNode default initialization and conditionally removed defaults for the Description attribute and for the SymbolicName property. To enable the previous behavior, enable the corresponding properties in OpcAutomatism.

2.51

• Changed2.51.0.0
  When using .NET Framework, version 4.7.2 or higher is now required.
• Changed2.51.0.0
  New parameters have been added to the method IOpcNodeHistoryProvider.ReadHistory() to support streaming of history values, instead of buffering all values in memory. In particular, the implementation now needs to return the values in reversed order when parameter timeFlowsBackward is true.

2.54

• Changed2.54.0.0
  Enhanced certificate validation especially for application instance certificates to support compliant validation of basic constraint extensions. This is required for CTT compliance.
• Changed2.54.0.0
  By default, the listener socket now uses an exclusive address when binding to the port. This behavior can be controlled with the new OpcServerBinding.UseExclusiveAddress property.

2.55

• Changed2.55.0.0
  The initial value of the OpcConditionNode.IsRetained property and its subtypes (OpcAcknowledgeableConditionNode and OpcAlarmConditionNode) including the traversal subtypes might be different starting with this version. This ensures the correct initial value according to the condition type's specific state machine. To understand the different conditions see OPC UA Part 9. In addition the documentation of the new OpcConditionRetainPolicy enumeration provides additional details. However the specific condition type uses by default the corresponding policy to provide compliant initial values. To override that you can use the value OpcConditionRetainPolicy.Manual for the OpcConditionNode.IsRetainedPolicy property to gain full control of the IsRetained property.

2.58

• Breaking2.58.0.0
  Introduced OpcRawObject, which represents a value of a structure the SDK cannot decode (an unknown data type or a field without a fixed ValueRank) with its encoding and encoded body, and OpcData.Encode to encode a structure as an OpcRawObject. Code that expected an array of bytes or an XmlElement for a value of an unknown structure now receives an OpcRawObject; its RawData holds what was returned before.
• Breaking2.58.0.0
  Introduced the attributes RolePermissions, UserRolePermissions, AccessRestrictions, and AccessLevelEx in OpcAttribute and OpcAttributes, the member DataTypeDefinition of OpcAttributes, and the types OpcRolePermission and OpcPermissions. Reading the DataTypeDefinition attribute now yields an OpcDataTypeInfo instead of a StructureDefinition or EnumDefinition of the stack, and reading RolePermissions or UserRolePermissions yields an array of OpcRolePermission instead of RolePermissionType.
• Breaking2.58.0.0
  Removed the CertificateFactory of the stack from the public API of the package, since the SDK does not provide CA signing or CRL generation. Code that uses CertificateFactory no longer compiles.
• Breaking2.58.0.0
  OpcSecurityAlgorithm.Auto and the default endpoints of the discovery server and of the OPC Classic wrapper server use Basic256Sha256 instead of the deprecated Basic256 (Sign) and Basic128Rsa15 (SignAndEncrypt). A client using Auto no longer connects to a server that offers only the deprecated policies.
• Changed2.58.0.0
  The certificate the SDK creates for an OpcServer also names the fully qualified name of the machine, so that clients that connect by that name accept it. An existing certificate remains unchanged.
• Breaking2.58.0.0
  OpcServer reports audit events only while OpcServerSecurity.IsAuditingEnabled is true, and only to clients connected over SignAndEncrypt or HTTPS with a user in the SecurityAdmin role, as defined by OPC UA. A server reports session audit events only after IsAuditingEnabled has been set to true.
• Breaking2.58.0.0
  State, StateChanged, and BreakDetected of OpcClient follow a lost connection detected by a failing service call (for example BadConnectionClosed or BadSessionIdInvalid) at once instead of with the next keep-alive, and a recreated session reconnects to a restarted server within one interval. Code that relied on the state changing only with the keep-alive now sees the change earlier.
• Breaking2.58.0.0
  The data type system of OPC UA provides all predefined data types (for example Integer, UInteger, Enumeration, or Image), each data type states its supertype as BaseType, and fields of data types derived from a built-in type (for example Duration, UtcTime, or LocaleId) are decoded. Built-in types and the structures of OPC UA now state their supertype as BaseType instead of none, and a field of a type derived from ByteString yields a ByteString instead of an array of bytes.
• Changed2.58.0.0
  OpcServer no longer traces a connection reset by a client as an error, neither during a read nor when it closes the socket.
• Breaking2.58.0.0
  OpcClient.ReconnectTimeout and DefaultReconnectTimeout are obsolete; use ReconnectInterval and DefaultReconnectInterval instead. Code that uses them receives a compiler warning, and a compiler error with TreatWarningsAsErrors.
• Breaking2.58.0.0
  The single-node history services OpcClient.ReadNodeHistoryProcessed, ReadNodeHistoryAtTime, and ReadNodeHistoryModified throw an OpcException with the status code of the server (for example BadAggregateNotSupported) for a node the server rejected, and return an empty result for a node the server accepted without values. Before, a KeyNotFoundException was thrown in both cases. Code that catches the KeyNotFoundException must catch the OpcException instead.
• Breaking2.58.0.0
  OpcDiscoveryClient (DiscoverEndpoints, DiscoverServers, and its constructors) throws an OpcException stating the reason (for example BadSecureChannelClosed) when the server cannot be reached, closes the channel during the handshake, or the discovery URL uses an unsupported scheme. The history navigators of OpcClient.ReadNodeHistory and ReadEventHistory throw an OpcException stating BadCommunicationError when a page was not finished within the maximum number of requests. Before, the ServiceResultException of the stack was thrown. Code that catches the ServiceResultException must catch the OpcException instead.
• Breaking2.58.0.0
  OpcViewDescription.Default is now a static readonly field, so that the default view cannot be replaced. Code that assigns OpcViewDescription.Default no longer compiles. Code compiled against an older version that reads OpcViewDescription.Default must be recompiled, because the property has become a field.
• Breaking2.58.0.0
  Issue with OpcServer, where a start changed the ServerConfiguration of the application, so that a restart offered anonymous access although only the OpcUserNameAcl was enabled. The server now works with a copy of the configuration. Code that reads Configuration.ServerConfiguration after the start sees the values it set itself instead of the policies in use.
• Breaking2.58.0.0
  Issue with reading processed history (for example OpcClient.ReadNodeHistoryProcessed), which requested both timestamps, so that a server could reject the request with BadTimestampsToReturnInvalid. The issue existed since version 1.5.11.0. The processed values no longer carry a server timestamp.
• Breaking2.58.0.0
  Issue with a structure described in a data type dictionary whose field refers to a data type known by its DataTypeDefinition only, which the client could not resolve. The issue existed since version 2.40.0.0. The Name and XmlName of such a data type now state the namespace of its node instead of the namespace of OPC UA.

2.59

• Breaking2.59.0.0
  Replaced the outdated dependency Portable.BouncyCastle (version 1.9.0) with BouncyCastle.Cryptography (version 2.7.0), whose assembly is named BouncyCastle.Cryptography.dll instead of BouncyCastle.Crypto.dll. CertificateFactoryRandomGenerator additionally provides AddSeedMaterial(ReadOnlySpan<byte>) and NextBytes(Span<byte>), which the IRandomGenerator of BouncyCastle.Cryptography declares for .NET 6 and later. Applications that deploy the assemblies themselves must deploy BouncyCastle.Cryptography.dll instead of BouncyCastle.Crypto.dll. Applications that reference Portable.BouncyCastle themselves and use its types must change to BouncyCastle.Cryptography, since both packages provide the same types.
• Changed2.59.0.0
  Removed the dependency on System.Management.
• Breaking2.59.0.0
  The operators <, <=, >, >=, and == of OpcFilterOperand throw an ArgumentNullException for a left operand that is null, and the constructors of OpcContentFilterElement throw an ArgumentNullException for operands that are null. Before, a NullReferenceException was thrown. Code that catches the NullReferenceException must catch the ArgumentNullException instead.
• Breaking2.59.0.0
  Removed the class OpcContentFilterElementFactory, which had no public members. Code that names the type no longer compiles; an instance of the type could never be obtained.
• Breaking2.59.0.0
  EndpointDescriptionExtensions.SetEndpointPolicy throws an ArgumentNullException for an endpoint policy that is null, and the indexer of OpcSecurityPolicyCollection throws an ArgumentNullException when null is set. Before, SetEndpointPolicy threw a NullReferenceException and the indexer stored an entry without a policy. Code that catches the NullReferenceException must catch the ArgumentNullException instead, and code that sets null using the indexer now fails.
• Breaking2.59.0.0
  The CertificateRequested event of OpcServer and OpcClient also occurs when the application certificate exists but is not valid, with the reason Invalid, UseNotAllowed, Revoked, TimeInvalid, IssuerUseNotAllowed, IssuerRevoked, or IssuerTimeInvalid (for example TimeInvalid for an expired certificate). The certificate is never replaced automatically (AutoCreateCertificate of the event data is false); unless the handler provides an alternative certificate, it remains in use and a trace entry is written. Before, such a certificate was used without notice. The event now also occurs when a server starts or a client connects with an invalid application certificate, so handlers that handle each reason like a missing certificate are called in this case too.
• Breaking2.59.0.0
  Removed OpcEventContext, which the SDK never created or returned. Code that references OpcEventContext no longer compiles.
• Breaking2.59.0.0
  ExtensionObjectExtensions.To<T> throws an ArgumentNullException instead of a NullReferenceException for an extension object that is null, and the Children of OpcAddObjectTypeNode and OpcAddVariableTypeNode throw an ArgumentNullException instead of a NullReferenceException when a command that is null is added or set. Code that catches the NullReferenceException must catch the ArgumentNullException instead.
• Changed2.59.0.0
  A custom IOpcNodeHistoryProvider should also return the value directly before and the value directly after the requested time range, so that the server can interpolate values when the history is read at specific times or processed. Otherwise such reads still result in BadNoData.
• Breaking2.59.0.0
  OpcNodeHistory<T> uses -1 (unlimited) as its default capacity instead of 0, with which each call to Add failed. A capacity of 0 or less than -1 is now rejected with an ArgumentOutOfRangeException, also by the constructors of OpcNodeHistorian. Code that passes a capacity of 0 (for example new OpcNodeHistory<T>(0, values)) now fails with an ArgumentOutOfRangeException.
• Breaking2.59.0.0
  OpcNodeHistorian.ModifiedHistory is an OpcModifiedNodeHistory instead of an OpcNodeHistory<OpcModifiedHistoryValue>. Code that uses the property as an OpcNodeHistory<OpcModifiedHistoryValue> must be changed: GetValues(DateTime) replaces the indexer by timestamp, while RemoveAt(DateTime), Replace, and the Replaced event are no longer available. Code compiled against a previous version must be recompiled.
• Breaking2.59.0.0
  Reading (for example with OpcClient.ReadNodeHistoryModified) and deleting (for example with OpcClient.DeleteNodeHistoryModified) the modified history of an OpcNodeHistorian refer to the timestamps of the values instead of the modification times. Several modifications of a value are returned from the most recent to the oldest one, also when reading backward. Code that reads or deletes the modified history using a time range of modification times now receives or deletes other values.
• Breaking2.59.0.0
  OpcClient.BrowseNode(OpcBrowseNode) and OpcClient.BrowseNodes throw an ArgumentNullException for a command that is null. Before, a NullReferenceException was thrown. Code that catches the NullReferenceException must catch the ArgumentNullException instead.
• Breaking2.59.0.0
  OpcClient.CallFunc throws an InvalidCastException if the first output argument is null and the result type is a non-nullable value type. Before, a NullReferenceException was thrown. Code that catches the NullReferenceException must catch the InvalidCastException instead.
• Breaking2.59.0.0
  OpcClient.CallMethods throws an ArgumentNullException for a command that is null. Before, such a command was skipped, so that the results of the following commands were returned at the index of the previous command, and a call of commands that are all null failed with an OpcException stating BadNothingToDo. Code that passes a command that is null now fails instead of receiving shifted results.
• Breaking2.59.0.0
  The single-command overloads OpcClient.CallMethod(OpcCallMethod), ReadNodeHistory(..., OpcReadNodeHistory), CreateNodeHistory, ReplaceNodeHistory, UpdateNodeHistory, DeleteNodeHistory, DeleteNodeHistoryAtTime, and DeleteNodeHistoryModified throw an ArgumentNullException with the ParamName command for a command that is null. Before, the ParamName stated commands.Item, and CallMethod(OpcCallMethod) failed with an OpcException stating BadNothingToDo. Code that catches the OpcException of CallMethod(OpcCallMethod) for a command that is null must catch the ArgumentNullException instead.
• Breaking2.59.0.0
  The OpcServer constructors that take a sequence of nodes throw an ArgumentNullException for a node that is null. Before, OpcServer.Start() failed with an OpcException. The exception now occurs when the server is constructed and is an ArgumentNullException instead of an OpcException.
• Breaking2.59.0.0
  OpcNode.ReadAttributeValueCore and OpcNode.WriteAttributeValueCore throw an ArgumentNullException for a value that is null. Before, a NullReferenceException was thrown. A derived class that catches the NullReferenceException must catch the ArgumentNullException instead.
• Breaking2.59.0.0
  The service requests built from commands (for example OpcCallMethodsRequest, OpcReadNodesRequest, or OpcWriteNodesRequest) throw an ArgumentNullException for a command that is null. Before, such a command was skipped, so that the results of the following commands were assigned to the wrong command. Code that passes a command that is null now fails instead of receiving shifted results.
• Breaking2.59.0.0
  OpcClient.CreateSubscription throws an OpcException stating BadServerNotConnected when the client has not been connected or has been disconnected. Before, a NullReferenceException was thrown. Code that catches the NullReferenceException must catch the OpcException instead.
• Breaking2.59.0.0
  OpcEventFilterFactory.Select throws an ArgumentNullException for operands that are null. Before, a NullReferenceException was thrown while the client was connected. Code that catches the NullReferenceException must catch the ArgumentNullException instead.
• Breaking2.59.0.0
  OpcEventFilterConstrainedFactory.Where combines the specified constraint with the constraint of the factory using a logical AND, like a single Where with both constraints combined using the & operator. Before, the elements of the specified constraint were only appended, so that the root element of the filter was still the first constraint and element operands of the appended constraint referred to wrong elements. An event filter built using chained Where calls now restricts the events by all constraints, so that a MonitoredItem may receive fewer events than before.
• Breaking2.59.0.0
  OpcClientApplication.Exit disconnects the client also in the states Connecting, Reconnecting, and Reconnected (the state the client takes after a reconnect with the same session); while the client connects, Exit waits until connecting has completed. In a non-interactive environment, Exit also ends Run if the client has already been disconnected, for example because reconnecting failed. Before, Exit did nothing in these states, so that the client stayed connected or kept reconnecting and Run did not return in a non-interactive environment (for example a service did not stop). The events Exiting and Exited are now raised in the states Connecting, Reconnecting, and Reconnected as well.
• Breaking2.59.0.0
  The constructors of OpcClientApplication, OpcServerApplication, and OpcServerServiceApplication check their arguments before the application is registered for the current thread. Before, a constructor that threw an ArgumentNullException left the failed instance registered, so that OpcApplication.Current returned it and the next constructor on the same thread threw an InvalidOperationException until the instance was garbage collected. After a failed construction, OpcApplication.Current now returns null instead of the failed instance.
• Changed2.59.0.0
  An application that has been garbage collected without a call of Exit no longer prevents the creation of the next application on the same thread. Before, the next constructor threw an ArgumentException.
• Changed2.59.0.0
  Applications can be created and exited on several threads at the same time. Before, this could corrupt the registration, so that OpcApplication.Current returned the application of another thread or an exception was thrown.
• Breaking2.59.0.0
  OpcServerApplication.Exit stops the server also in the state Suspended. Before, Exit did nothing in this state, so that the server stayed suspended and Run did not return in a non-interactive environment. The events Exiting and Exited are now raised in this state as well.
• Changed2.59.0.0
  OpcNodeManager.SyncRoot, GetNode(string), and IsNodeReadyToPublish throw an InvalidOperationException when the server using the node manager has not yet been started, like the other members of the node manager that require a started server. Before, a NullReferenceException was thrown.
• Changed2.59.0.0
  OpcClient.BrowseNode and BrowseNodes use OpcBrowseNode.IncludeSubtypes once it has been set, as the Browse service does. A command without the value set follows the subtypes of its reference types as before.
• Breaking2.59.0.0
  The HTTPS endpoints of OpcServer let the operating system choose the TLS versions instead of offering TLS 1.0, 1.1, and 1.2. Clients that only support TLS 1.0 or 1.1 can no longer connect over HTTPS where the operating system has disabled these versions.
• Breaking2.59.0.0
  Issue with OpcFilterOperand.Between, which passed the operands in the order lower bound, operand, upper bound, so that, for example, a.Between(1, 5) determined whether 1 is between a and 5 instead of whether a is between 1 and 5. The operands are now passed in the order defined by OPC UA. Code that compensated for the issue by calling Between on the lower bound (for example lower.Between(a, upper)) now determines whether the lower bound is between a and the upper bound and must be changed to a.Between(lower, upper).
• Breaking2.59.0.0
  Issue with OpcHistoryValue.Create(OpcValue), which created a history value sharing the data of the specified value, so that setting the value of one of them changed the data of the other, while its Value property still returned the previous value. The history value now uses a copy of the data. Code that changes an OpcValue after passing it to Create, or a history value created by Create, no longer changes the data of the other value.
• Breaking2.59.0.0
  Issue with OpcSecurityPolicyCollection.CopyTo, which copied each policy from the specified array index on to the same index of the array, so that the policies before that index were missing, and which failed with an ArgumentOutOfRangeException for an empty array. The method now copies all policies to the array starting at the specified index, like List<T>.CopyTo, and throws an ArgumentException if the array is too small. Code that passes an array index greater than zero receives all policies starting at that index instead of a part of them at their own index, and code that passes an array that is too small for all policies receives an ArgumentException.
• Breaking2.59.0.0
  Issue with the CertificateRequested event of OpcServer and OpcClient, where a certificate provided using AlternativeCertificate of the event data was not used: a server without an application certificate failed to start ("Server does not have an instance certificate assigned"), and otherwise the certificate of the application store remained in use. The provided certificate is now used, also on later starts and connects; it must contain its private key. Handlers that set AlternativeCertificate to another certificate now change the certificate the application uses.
• Breaking2.59.0.0
  Issue with OpcStruct, where creating the data type of a structure with an array field whose data type is unknown failed with a NullReferenceException. An InvalidOperationException that names the data type, the field, and the structure is now thrown. Code that catches the NullReferenceException in this case does not catch the InvalidOperationException.
• Breaking2.59.0.0
  Issue with OpcEnum, where fields defined without a value got the value 0 if another field was defined with a value other than 0, and where the specified OpcEnumField instances were changed. Like in C#, a field defined without a value now follows the value of the field before it (A, B, C = 5, D results in 0, 1, 5, 6), and the specified instances remain unchanged. Enumerations with fields defined without a value next to fields defined with a value, and enumerations whose fields are all defined with the value 0, get other values; the Value of an OpcEnumField specified without a value remains 0, and GetFields returns copies.
• Breaking2.59.0.0
  Issue with OpcServer, where a request of the services AddNodes, AddReferences, DeleteNodes, DeleteReferences, or Call that contained a command with a null identifier was rejected as a whole (BadNothingToDo, for AddNodes, DeleteNodes, and DeleteReferences BadUnexpectedError). The other commands are now executed, and the command with the null identifier has the status defined by OPC UA (BadParentNodeIdInvalid, BadNodeIdInvalid, BadSourceNodeIdInvalid, BadTargetNodeIdInvalid, BadReferenceTypeIdInvalid, or BadMethodInvalid). The issue existed since version 2.7.0.0, for Call since version 2.50.5.0. Such a request is no longer rejected, so that RequestValidating is raised with a good result, the request is processed, and it is not counted in RejectedRequestsCount of the server diagnostics. Server applications that relied on the rejection must handle commands with a null identifier themselves.