QuickOPC: How to enable extended tracing

Note: For information that applies to version 2020.3 and older, click View history and select the page dated January 7, 2021.

Enabling the extended tracing

For advanced troubleshooting, it is sometimes necessary to obtain information about QuickOPC internal status and activities. This can be done by enabling extended tracing, as described in this application note. Most of the tracing is for OPC UA, but there is some tracing for other OPC specifications as well.

The logging is enabled by various .NET trace switches, and settings in configuration file sections. Unless you are able to observe the output in the debugger or using a special tool, you also need to direct the trace to a proper listener, using the standard means provided by .NET tracing facility. It is up to you how you enable the switches or configure the listener(s). Typically, it is done using the application configuration file, with the advantage that it can be done without rebuilding the application.

The example below shows the application configuration file with common parts of the extended tracing enabled.

 <?xml version="1.0"?>
 <configuration>
   <configSections>
     <section
       name="OpcLabs.EasyOpc.UA.Toolkit.SdkTrace"
       type="OpcLabs.EasyOpc.UA.Toolkit.SdkTraceSection,OpcLabs.EasyOpcUA" />
   </configSections>
   <OpcLabs.EasyOpc.UA.Toolkit.SdkTrace traceOutput="3" >
   </OpcLabs.EasyOpc.UA.Toolkit.SdkTrace>
   <startup>
     <supportedRuntime version="v4.0" sku=".NETFramework,Version=v4.5"/>
   </startup>
   <system.diagnostics>
     <switches>
       <add name="EasyUAClientEngineBase" value="Verbose" />
       <add name="NetSdkEasyUAClient" value="Verbose" />
       <add name="NetSdkEasyUASubscriber" value="Verbose" />
       <add name="OpcLabs.Boxing.Applications" value="Verbose" />
       <add name="OpcLabs.Boxing.Progress" value="Verbose" />
       <add name="OpcLabs.CallDiagnostics.Display.CallPort" value="1" />
       <add name="OpcLabs.CallDiagnostics.Display.Enabled" value="1" />
       <add name="OpcLabs.CallDiagnostics.Display.EnterPort" value="1" />
       <add name="OpcLabs.CallDiagnostics.Display.ExitPort" value="1" />
       <add name="OpcLabs.CallDiagnostics.Display.LeavePort" value="1" />
       <add name="OpcLabs.CallDiagnostics.Display.TickCount" value="1" />
       <add name="OpcLabs.Configuration.Retrieve" value="Verbose" />
       <add name="OpcLabs.EasyOpc.UA.Toolkit.Sdk.DisplayCalls" value="1" />
       <add name="OpcLabs.EasyOpc.UA.Toolkit.SdkCallback.DisplayCalls" value="1" />
       <add name="OpcLabs.EasyOpc.UA.Toolkit.SdkEnvironment.DisplayCalls" value="1" />
       <add name="OpcLabs.EasyOpc.UA.Toolkit.SdkMethod.DisplayCalls" value="1" />
       <add name="OpcLabs.EasyOpc.UA.Toolkit.SdkTarget.DisplayCalls" value="1" />
       <add name="OpcLabs.EventTracing.LogEntries" value="Verbose" />
       <add name="OpcLabs.EventTracing.SafeCritical" value="Verbose" />
       <add name="OpcLabs.Reflection.AssemblyLoading" value="Verbose" />
       <add name="UAEngineBase" value="Verbose" />
       <add name="UASmartClientEngine" value="Verbose" />
     </switches>
   </system.diagnostics>
 </configuration>

The relevant parts of the file are highlighted. Specifically, following information will be contained in the traces:

• All trace information from inside OPC UA .NET Stack and SDK.
• Calls to and from OPC UA .NET Stack and SDK.
• Log entries generated by the component.

Please refer to Microsoft documentation for details on the application configuration files, the diagnostic switches, the trace listeners, and so on. The application configuration file needs to be named the same as your application, with an added “.config” extension, and placed alongside the application. For example, for “MyApp.exe”, the configuration file is “MyApp.exe.config”. Note that the development tools sometimes provide “shortcuts” for the naming and placing procedure. For example, Visual Studio C# projects contain an app.config file, which becomes the application configuration file automatically – Visual Studio copies it to the output folder and renames it appropriately.

Note: Under COM platform, QuickOPC objects get loaded into the process of the application that creates and calls them. You therefore need to create or modify the configuration file for the application itself (as if it were a .NET application). In hosted environments, such as ASP.NET, the name and location of the configuration file may be different as well.

By default, the traces are directed to the Windows debug output, which you can observe e.g. when you run the program under a debugger, or it can be viewed and captured using specialized tools such Sysinternals’ DebugView (http://technet.microsoft.com/en-us/sysinternals/bb896647.aspx ).

Trace Switches

Following table lists some selected trace switches and their meaning.

Name	Description	Type	Default value
OpcLabs.EasyOpcClassicRaw.OCKClient.BrowseNodes	Browsing for OPC DA nodes.	BooleanSwitch	0
OpcLabs.Licensing.Invoke	License invocation.	BooleanSwitch	0
OpcLabs.Licensing.Verify	License verification.	BooleanSwitch	0

Switches in Debug configurations

The switches listed here are only functional in Debug configurations. Note that Debug configurations of the software are not normally made available to customers.

Name	Description	Type	Default value
DotPrologEngine.DebugTracingDebugger	Tracing debugger.	BooleanSwitch	0

Trace Listener Configuration

If you do not want to use the default debug trace configuration (directing the traces to the debug output), you can configure the trace listener(s) in various ways. Please refer to Microsoft documentation for details. For example, to store the output into a comma-delimited file “Trace.csv” (in the same folder as the application), use the following configuration part:

 <system.diagnostics>
     <trace autoflush="true" indentsize="4">
       <listeners>
         <add name="myListener" 
              type="System.Diagnostics.DelimitedListTraceListener"
              traceOutputOptions="DateTime, ProcessId, ThreadId"
              delimiter=","
              initializeData="Trace.csv" />
         <remove name="Default" />
       </listeners>
     </trace>
   </system.diagnostics>