Online Forums

Technical support is provided through Support Forums below. Anybody can view them; you need to Register/Login to our site (see links in upper right corner) in order to Post questions. You do not have to be a licensed user of our product.

Please read Rules for forum posts before reporting your issue or asking a question. OPC Labs team is actively monitoring the forums, and replies as soon as possible. Various technical information can also be found in our Knowledge Base. For your convenience, we have also assembled a Frequently Asked Questions page.

Do not use the Contact page for technical issues.

Readfunction gets stuck after disconnection

1
2
3

RH
Offline
Elite Member

More

14 Dec 2016 13:41 #4647 by RH

Replied by RH on topic Readfunction gets stuck after disconnection

Thank you for the update, license covered this update as our purchase was not very long ago.
I checked it and it seems to work now.

Best regards

Please Log in or Create an account to join the conversation.

support
Offline
Moderator

More

09 Dec 2016 11:33 #4628 by support

Replied by support on topic Readfunction gets stuck after disconnection

We have made the fix to a newly released version (2016.2), which is now available from the Download area on this site. Please use this new version.

Your license should cover it, if you have purchased QuickOPC when version 5.40 was current, OR if you have purchased QuickOPC earlier, but with a maintenance that covers this release date. In the unlikely case you are not covered by the above options already, let me know and we will extend your license to version 2016.2 free of charge.

Best regards

The following user(s) said Thank You: RH

Please Log in or Create an account to join the conversation.

RH
Offline
Elite Member

More

02 Dec 2016 11:26 #4621 by RH

Replied by RH on topic Readfunction gets stuck after disconnection

That's good news, thank you for your support!

Please Log in or Create an account to join the conversation.

support
Offline
Moderator

More

02 Dec 2016 10:58 #4620 by support

Replied by support on topic Readfunction gets stuck after disconnection

Thank you very much. This has really helped. I have analyzed the call stack and I can confirm that there is a deadlock, and I think I can see how it has come to it.

The question now is, how to properly fix it - it needs to be done carefully in order not to break something else. I will inform you here when we have more information.

Best regards

Please Log in or Create an account to join the conversation.

RH
Offline
Elite Member

More

01 Dec 2016 10:16 #4612 by RH

Replied by RH on topic Readfunction gets stuck after disconnection

After setting the options as described in the knowledge base article, the debugging works as described.

I reproduced the error by disconnecting and connecting again and these are the callstacks I have after attaching the debugger:

File Attachment:

File Name: CallStackOPCLabs.txt
File Size:13 KB

The cable is currently connected, but the library hangs in Function ReadMultiple which should be Thread 5780. Another test program of mine can connect and read values without a problem while the other program hangs, so it's definitely no network issue.

Please Log in or Create an account to join the conversation.

support
Offline
Moderator

More

01 Dec 2016 08:32 - 01 Dec 2016 08:33 #4611 by support

Replied by support on topic Readfunction gets stuck after disconnection

I have written a Knowledge Base article with the sequence of steps: kb.opclabs.com/Obtaining_.NET_call_stacks_in_a_COM_application .

The message you got is essentially harmless and can be ignored, but there are other important steps to be made.

Best regards

Last edit: 01 Dec 2016 08:33 by support.

Please Log in or Create an account to join the conversation.

support
Offline
Moderator

More

28 Nov 2016 15:39 #4603 by support

Replied by support on topic Readfunction gets stuck after disconnection

OK I will install VS Community, try to debug a Delphi program, and let you know the sequence of steps.

Regards

Please Log in or Create an account to join the conversation.

RH
Offline
Elite Member

More

28 Nov 2016 15:37 #4602 by RH

Replied by RH on topic Readfunction gets stuck after disconnection

The call stack windows is displayed, but it says something like "The app has been stopped, but there is no code to display because all threads run external code (system or framework code)". I only have a screenshot in german language, but that's how it looks like:

2016_11_28_16_33_11_Haltemodus_Debugging_Microsoft_Visual_Studio.png

Do I need to add some files to the search path or something? I just installed it without setting anything...

Regards

Please Log in or Create an account to join the conversation.

support
Offline
Moderator

More

28 Nov 2016 14:49 #4601 by support

Replied by support on topic Readfunction gets stuck after disconnection

In my Visual Studio (which is not a Community), I can use "Debug -> Windows -> Call stack" command from the menu. Do you have that in your VS?

Source code should not be necessary for this, as in the call stack we need just the methods names, and they are already in .NET assembly metadata.

Regards

Please Log in or Create an account to join the conversation.

RH
Offline
Elite Member

More

28 Nov 2016 12:56 #4600 by RH

Replied by RH on topic Readfunction gets stuck after disconnection

I installed the community version of Visual Studio for testing. But I need some more infos as I'm not very used to it.

I can attach the debugger to my application and I can pause and continue the .NET part of the application, while my application is running. The only problem is, that Visual Studio doesn't show any callstack at all, when I press pause. I guess, I need to configure a project with some source code? I just started Visual Studio and attached the debugger which is obviously not enough. Can you please supply some short instruction on how to do it correctly?

Thank you for your help.

Please Log in or Create an account to join the conversation.