Configuring the timeout value from config file works fine.
I set 45 seconds as timeout value, all the application starts without any errors in startup.


I have license for the version QuickOPC-Classic 5.12.1308.1, Can I use the same license for the latest version 5.23.1225.1 or should I purchase a new one?


Thank you

Okay sir.

Let me know when a new build is available. I expect this changes in both versions 5.23 and 5.30, since I may use both .Net versions 3.5 as well as 4.5

Dear Sir,

Thank you for dealing this issue.

Configuring the timeout value from the config file is good. But, still there may be a possibility to get the Timeout Exception at some cases. So, please think of it.

I think the global shared file is created in the Temp folder with name like amd64_OpcLabs.EasyOpcClassicRaw_5.23.1211.1.dll. But the OPC Web Client 3.02 does not generate the global file in Temp folder (I do not know that, it may generate the global file some where). Is there any possibility that instead of sharing the global file, can you generate individual file for each application? or can you add a configuration to
1. Share the global file (or)
2. Create an individual file for each application

Thank you for your response

I still have issue, Please see below.

1. I tested the OPCTest1 and OPCTest2 applications with the QuickOPC 5.23(Updated on May 26, 2014) and run both the application at system startup.
2. Again, one application works correctly and the second one throws some other exception.

Exception Text :

System.TypeInitializationException: The type initializer for 'OpcLabs.EasyOpc.DataAccess.EasyDAClient' threw an exception. ---> System.TimeoutException: Timeout waiting for exclusive access on execution mutex "Global\OpcLabs-{76505F20-51A1-43D3-8E2A-6AAEDAB5DBCA}-0xD6CC1689".

at OpcLabs.BaseLib.Threading.ExclusiveExecution..ctor(String regionName, Boolean global, Int32 lockTimeout)
at OpcLabs.BaseLib.Threading.ExclusiveExecutionRegion.WaitBegin(Int32 lockTimeout)
at OpcLabs.BaseLib.Reflection.AssemblyLoader.LoadFromManifestResourceThroughFile(Assembly manifestAssembly, String resourceName, String fileName, Assembly requestingAssembly)
at OpcLabs.BaseLib.Reflection.AssemblyLoader.LoadFromManifestResource(Assembly manifestAssembly, AssemblyName assemblyName, Assembly requestingAssembly)
at OpcLabs.BaseLib.Reflection.AssemblyLoader.InternalLoad(AssemblyName assemblyName, Assembly requestingAssembly)
at OpcLabs.BaseLib.Reflection.AssemblyLoader.LoadExtended(AssemblyName assemblyName, Assembly requestingAssembly)
at OpcLabs.EasyOpc.Assemblies.get_EasyOpcClassicRaw()
at OpcLabs.EasyOpc.DataAccess.EasyDAClient..cctor()
--- End of inner exception stack trace ---
at OpcLabs.EasyOpc.DataAccess.EasyDAClient..ctor()
at OPCTest1.OPCTest1.OPCTest1_Load(Object sender, EventArgs e) in D:\OPCTest1\OPCTest1.vb:line 7
at System.EventHandler.Invoke(Object sender, EventArgs e)
at System.Windows.Forms.Form.OnLoad(EventArgs e)
at System.Windows.Forms.Form.OnCreateControl()
at System.Windows.Forms.Control.CreateControl(Boolean fIgnoreVisible)
at System.Windows.Forms.Control.CreateControl()
at System.Windows.Forms.Control.WmShowWindow(Message& m)
at System.Windows.Forms.Control.WndProc(Message& m)
at System.Windows.Forms.ScrollableControl.WndProc(Message& m)
at System.Windows.Forms.ContainerControl.WndProc(Message& m)
at System.Windows.Forms.Form.WmShowWindow(Message& m)
at System.Windows.Forms.Form.WndProc(Message& m)
at System.Windows.Forms.Control.ControlNativeWindow.OnMessage(Message& m)
at System.Windows.Forms.Control.ControlNativeWindow.WndProc(Message& m)
at System.Windows.Forms.NativeWindow.Callback(IntPtr hWnd, Int32 msg, IntPtr wparam, IntPtr lparam)

Note : I tested in both Windows XP service pack 3 and Windows 7 operating systems. Error occurs frequently in Windows XP and rarely in windows 7.

I had used OPC Web client 3.02 in my applications. Generally, I had started 5 to 6 applications on system startup. Everything works fine without any problem. Now I am upgrading my applications to Quick OPC Classic 5.12.1308.1
If I start all the 6 applications on system startup (that is all the 6 applications starts at the same time), I get the following error.

************** Exception Text **************
System.TypeInitializationException: The type initializer for 'OpcLabs.EasyOpc.DataAccess.EasyDAClient' threw an exception. ---> System.IO.FileLoadException: Could not load file or assembly 'file:///C:\Documents and Settings\[user]\Local Settings\Temp\x86_OpcLabs.EasyOpcClassicRaw_5.12.1396.1.dll' or one of its dependencies. The process cannot access the file because it is being used by another process. (Exception from HRESULT: 0x80070020)
File name: 'file:///C:\Documents and Settings\[user]\Local Settings\Temp\x86_OpcLabs.EasyOpcClassicRaw_5.12.1396.1.dll'
at System.Reflection.Assembly._nLoad(AssemblyName fileName, String codeBase, Evidence assemblySecurity, Assembly locationHint, StackCrawlMark& stackMark, Boolean throwOnFileNotFound, Boolean forIntrospection)
at System.Reflection.Assembly.nLoad(AssemblyName fileName, String codeBase, Evidence assemblySecurity, Assembly locationHint, StackCrawlMark& stackMark, Boolean throwOnFileNotFound, Boolean forIntrospection)
at System.Reflection.Assembly.InternalLoad(AssemblyName assemblyRef, Evidence assemblySecurity, StackCrawlMark& stackMark, Boolean forIntrospection)
at System.Reflection.Assembly.InternalLoadFrom(String assemblyFile, Evidence securityEvidence, Byte[] hashValue, AssemblyHashAlgorithm hashAlgorithm, Boolean forIntrospection, StackCrawlMark& stackMark)
at System.Reflection.Assembly.LoadFrom(String assemblyFile)
at OpcLabs.BaseLib.AssemblyExtension.LoadFrom(String assemblyFile, String requestingPath)
at OpcLabs.BaseLib.AssemblyLoader.LoadFromManifestResourceThroughFile(Assembly manifestAssembly, String resourceName, String fileName, Assembly requestingAssembly)
at OpcLabs.BaseLib.AssemblyLoader.LoadFromManifestResource(Assembly manifestAssembly, AssemblyName assemblyName, Assembly requestingAssembly)
at OpcLabs.BaseLib.AssemblyLoader.InternalLoad(AssemblyName assemblyName, Assembly requestingAssembly)
at OpcLabs.BaseLib.AssemblyLoader.LoadExtended(AssemblyName assemblyName, Assembly requestingAssembly)
at OpcLabs.EasyOpc.Assemblies.get_EasyOpcClassicNetRaw()
at OpcLabs.EasyOpc.DataAccess.EasyDAClient..cctor()



I had tested this issue with the latest versions "Quick OPC Classic 5.12.1396.1" and "Quick OPC Classic 5.20.1016.1". Still I get the same error.

NOTE: If I run the applications individually, it works well. I get this error when I run two or more applications at the same time. Also this error was not occurred all the time.


Steps to reproduce the above error:

1. Create VB.NET application and add reference EasyOPC.NET Library.
2. At the code behind of the form, copy and paste the following code.

Imports OpcLabs.EasyOpc.DataAccess

Public Class OPCTest1
Public m_objOPCServer As EasyDAClient

Private Sub OPCTest1_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
m_objOPCServer = New EasyDAClient
End Sub
End Class

3. In the same way create another VB.NET application 'OPCTest2' and follow the same procedure.

4.Copy the shortcut of OPCTest1 and OPCTest2 applications under the Starup folder on windows server 2008 R2 / Windows 7 / XP.

5. Restart your machine.

Note : The error raises at the line 'm_objOPCServer = New EasyDAClient'.