- Posts: 40
- Thank you received: 1
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.
- Forum
- Discussions
- QuickOPC-Classic in COM
- Installation, Deployment
- Different QuickOPC runtime revisions on the same PC
Different QuickOPC runtime revisions on the same PC
Thank you for your efforts.
Please Log in or Create an account to join the conversation.
I am unable to reproduce this one in my environment.
I suggest to close it as unresolved, due to low priority.
Thank you for understanding.
Please Log in or Create an account to join the conversation.
Guest OS is Windows 10 x86 1909 build 18363.418
Well, this became less troublesome for me now, since I know the problem appears only running in a shared folder.
However it still may be interesting for you, as QuickOPC 2019.1 did not do this, therefore it may be a new bug,
optionally producing other undiscovered malfunctions. So please let me know if you have any questions,
and I will try to help you further in debugging on my best.
Please Log in or Create an account to join the conversation.
Guest OS is Windows 10 x86 1909 build 18363.418
Well, this became less troublesome for me now, since I know the problem appears only running in a shared folder.
However it still may be interesting for you, as QuickOPC 2019.1 did not do this, therefore it may be a new bug,
optionally producing other undiscovered malfunctions. So please let me know if you have any questions,
and I will try to help you further in debugging on my best.
Please Log in or Create an account to join the conversation.
Please give me some time. I will to reproduce as closely as possible what you are doing. This is somewhat complicated, because in an unlucky coincident, we have recently switched our virtualization from VMWare to VirtualBox, so if the problem depends on the VMWare, I would have to go back to VMWare.
I will also need the precise version of the Windows 10 in the VM guest - taken from the WINVER command.
Thank you
Please Log in or Create an account to join the conversation.
The KB article is very interesting.
var
EasyDAClient: _EasyDAClient;
procedure TForm1.FormCreate(Sender: TObject);
begin
try
EasyDAClient := CoEasyDAClient.Create;
except
on E: EOleException do
begin
ShowMessage(Format('*** Failure: %s', [E.GetBaseException.Message]));
Exit;
end;
end;
end;
procedure TForm1.Timer1Timer(Sender: TObject);
begin
try
Edit1.Text := EasyDAClient.ReadItemValue('', 'Matrikon.OPC.Simulation.1','Random.UInt1');
except
on E: EOleException do
begin
ShowMessage(Format('*** Failure: %s', [E.GetBaseException.Message]));
Exit;
end;
end;
end;
end.
Please Log in or Create an account to join the conversation.
Yes please test with the exception handling.
I cannot give complete guarantee that the Delphi examples are correct in terms of proper freeing. We are no Delphi experts here. In fact I recently gave the task of checking whether the freeing is OK in those Delphi examples to an external developer, and I am waiting for his answer.
Earlier, we had written an article on this topic - see kb.opclabs.com/Reference_counting_in_Delphi - but the point is, I am not 100% sure if what is in the article is fully correct. Hopefully it is. The task of the external person is also to make the actual long-running tests, to check if there are memory leaks. It is somewhat complicated because the underlying objects are .NET objects, and it is OK for the .NET object to remain in memory until the garbage collector decides to free it, so what looks like a "momentary" leak does not necessarily mean a "true, permanent" leak.
Regards
Please Log in or Create an account to join the conversation.
Yes, I used the sample code. I did no exception handling in this test.
I found some samples in the "Doc Examples" I will test it that way and will come back with the report.
I see in the examples that you use only create methods.
Why is not there any freeing?
I see FreeAndNil command only in the subscription examples.
Please Log in or Create an account to join the conversation.
thanks for the video and the update, it is quite illustrative.
I have 2 more questions:
1. Is there something interesting in Windows application event log, around the time the application unexpectedly exits? : Event Viewer -> Event Viewer (Local) -> Windows Logs -> Application.
2. Guessing from the name of your EXE, it might be made by modifying the ReadAndDisplayExample. Unfortunately, this example has no proper exception handling. Do you have some exception handling in tour code, and if so, can you show the code here? My idea was that with the exception handling, there might be a way to obtain some information about what is happening, if the exception is caught and displayed.
Best regards
Please Log in or Create an account to join the conversation.
3. QuickOPC is installed with the production installer to the own virtual hard drive of guest and to the default location
Additional info:
I have tested it with a shared folder that have a drive letter assigned. Same result.
Please Log in or Create an account to join the conversation.
- Forum
- Discussions
- QuickOPC-Classic in COM
- Installation, Deployment
- Different QuickOPC runtime revisions on the same PC