Hi,
my OPC client developed with QuickOPC was working just fine until one day no item changes where processed anymore. I saw that my EventHandler for the
Code:
'EasyDAClient.ItemChanged'
didn't trigger anymore. I didn't change anything in that pipeline which was confusing. The application itself logs all the exceptions, but there was nothing. So i checked the Event log of Windows which prompts the following:
COM security initialization (process "OPC Interface WTEB" Id 38660, application domain "OPC Interface WTEB.exe" Id 1) for requestor 'ComSecurityInitializingEasyDAClient' failed; the initialization object was: (Default).
CoInitializeSecurity failure (0x80010119): Die Sicherheit muss initialisiert werden, bevor Schnittstellen gemarshallt oder unmarshallt werden. Änderungen können nach der Initialisierung nicht vorgenommen werden.
+ This error (RPC_E_TOO_LATE) is not uncommon in hosted .NET applications. Depending on various factors, it might be possible to prevent it, or safely ignore it (if COM works as intended). Consult the product documentation.
+ Current thread name: "", from thread pool: yes, managed thread Id: 19, apartment state: MTA.
After some digging around i found your thread about COM management:
COM management - OPC Labs Knowledge Base
I applied all the suggestions but nothing seems to restore the behaviour. So here is some code:
Startup:
Code:
<MTAThread>
Public Shared Sub Main(s As String())
ComSetup.Initialize()
If Environment.UserInteractive Then
mvoService = New OPCService
mvoService.CanStop = True
mvoService.Type = OPCService.ApplicationType.Console
mvoService.RunAsConsole(s)
System.Console.ReadLine()
End If
End Sub
ComSetup (was first introduced after the issue occured but didn't change anything)
Code:
Public Class ComSetup
Private Shared lock As New Object
Private Shared initialized As Boolean = False
Public Shared Sub Initialize()
SyncLock lock
If initialized Then
Return
End If
Try
'ComManagement.Instance.Configuration.SecurityParameters.UseCustomSecurity = True
'ComManagement.Instance.Configuration.SecurityParameters.TurnOffCallSecurity = True
ComManagement.Instance.Configuration.SecurityParameters.EnsureDataIntegrity = True
ComManagement.Instance.AssureSecurityInitialization()
Catch ex As Exception
End Try
initialized = True
End SyncLock
End Sub
End Class
Handling subscriptions and item changes (i can guarantee that we have items being subscribed with Handles)
Code:
Public Class OpcDAProvider
Implements IDataProvider
Public Const ciOPC_SERVER_FAILED As Integer = &HC0049001
Public Const ciOPC_SERVER_SHUTDOWN As Integer = &HC0049006
Public Const ciRPC_SERVER_UNAVAILABLE As Integer = -&H7FF8F946
Private m_Wrapper As OpcWrapper
Private m_State As OpcWrapper.SubscriptionState = OpcWrapper.SubscriptionState.Idle
Private m_Variables As New HashSet(Of OpcVariable)(VariableEqualityComparer.Default)
Private m_Client As EasyDAClient
Public Sub New(wrapper As OpcWrapper)
m_Wrapper = wrapper
m_Client = WTEB.OPC.Functions.CreateDAClient()
AddHandler m_Client.ItemChanged, AddressOf m_Client_ItemChanged
End Sub
Private Sub m_Client_ItemChanged(<NotNull> sender As Object, <NotNull> e As EasyDAItemChangedEventArgs)
Try
With e
If .Succeeded Then
If .Vtq.HasValue AndAlso HasAcceptedQuality(e) Then
Wrapper.Process(OpcSubscriptionValue.FromDAItemChange(e, Me))
ElseIf AppManager.ServiceSettings.VerboseLogs Then
Logger.WriteWarning("DA-Provider", $"ignoring data change for {e.Arguments.ItemDescriptor.NodeId} because it has no value or the status was bad (status: {e.Vtq.Quality.InternalValue})")
End If
Else
If .Exception IsNot Nothing Then
CheckServerStatus(.Arguments.ServerDescriptor, .Exception)
m_Wrapper.HandleSubscriptionError(DirectCast(.Arguments.State, IVariable), .Exception)
End If
End If
End With
Catch ex As Exception
Logger.WriteException(ex)
End Try
End Sub
Public Sub Subscribe() Implements IDataProvider.Subscribe
Dim subscriptions = buildDAItemList()
Dim subscriptionHandles = m_Client.SubscribeMultipleItems(subscriptions)
For i As Integer = 0 To subscriptionHandles.Length - 1
DirectCast(subscriptions(i).State, OpcVariable).Handle = subscriptionHandles(i)
Next
m_State = OpcWrapper.SubscriptionState.Listening
End Sub
...
Initialization of EasyDAClient
Code:
Public Function CreateDAClient() As OpcLabs.EasyOpc.DataAccess.EasyDAClient
'ComManagement.Instance.Configuration.SecurityParameters.UseCustomSecurity = This.Configuration.UseCustomSecurity
'ComManagement.Instance.Configuration.SecurityParameters.TurnOffCallSecurity = This.Configuration.TurnOffCallSecurity
'ComManagement.Instance.Configuration.SecurityParameters.TurnOffActivationSecurity = This.Configuration.TurnOffActivationSecurity
Dim oClient As New OpcLabs.EasyOpc.DataAccess.EasyDAClient
oClient.Isolated = This.Configuration.IsolatedClient
oClient.InstanceParameters.Mode.AllowSynchronousMethod = True
oClient.InstanceParameters.Mode.AllowAsynchronousMethod = True
oClient.InstanceParameters.Mode.DesiredMethod = OpcLabs.EasyOpc.DataAccess.Engine.DAReadWriteMethod.Asynchronous
oClient.InstanceParameters.Timeouts.BrowseAccessPaths = This.Configuration.TimeoutClient
oClient.InstanceParameters.Timeouts.BrowseNodes = This.Configuration.TimeoutClient
oClient.InstanceParameters.Timeouts.BrowseProperties = This.Configuration.TimeoutClient
oClient.InstanceParameters.Timeouts.BrowseServers = This.Configuration.TimeoutClient
oClient.InstanceParameters.Timeouts.ReadItem = This.Configuration.TimeoutClient
oClient.InstanceParameters.Timeouts.WriteItem = This.Configuration.TimeoutClient
oClient.InstanceParameters.HoldPeriods.ItemDetach = This.Configuration.HoldClient
oClient.InstanceParameters.HoldPeriods.ServerDetach = This.Configuration.HoldClient
oClient.InstanceParameters.HoldPeriods.TopicRead = This.Configuration.HoldClient
oClient.InstanceParameters.HoldPeriods.TopicWrite = This.Configuration.HoldClient
Return oClient
End Function
More useful information
- When calling ComSetup.Initialize() directly after steping into Main() we still get the message with RPC_E_TOO_LATE
- The apartment state is MTA
- I have tried changing the Authentication level to Packet Integrity (haven't restarted the PC though)
- No errors are thrown after subscribing via the EasyDAClient
- im using the OpcLabs.QuickOpc nuget package version 5.83.477
- i have tried different combinations of the SecurityParameters
- i have reinstalled QuickOPC and with that the Kit server which i am trying to communicate with
- i have another QuickOPC application which is working just fine which makes this even less understandable
I am not an expert when it comes to COM and i assume this is the root cause as all of the other logic of my client is working just fine, so i would greatly appriciate your help.
Best Regards
Tom
