Professional OPC
Development Tools

logos

lupa

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.

  1. Forum
  3. Discussions
  5. QuickOPC-UA in COM
  7. Reading, Writing, Subscriptions
  9. Filter subscriptions

Filter subscriptions

More
13 Apr 2022 17:00 #10808 by support
Replied by support on topic Filter subscriptions
Hello.

I do not have C++ example at hand, but there is an example for this available in other COM-based tools: Object Pascal, PHP, VB6. Writing the same in C++ should not be especially difficult.

Here it is: opclabs.doc-that.com/files/onlinedocs/QuickOpc/Latest/User%2...e%20nodes%20with%20filter.html

Note: The SubscribeDataChange method in COM does not have these more advanced options. You need to switch to SubscribeMultipleMonitoredItems.

Does it help?

Best regards

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

More
13 Apr 2022 07:38 - 13 Apr 2022 09:50 #10805 by federica
Filter subscriptions was created by federica
Hi,

I'm using QuickOPC COM, developing in C++.

I want to be notified when a particular tag in the OPC server will change its value.
I'm only interested in receiving new data only when the value has changed.
How can I add a filter to the "SubscribeDataChange" function (like "UADataChangeTrigger.StatusValue")?

Thanks,
Federica
Last edit: 13 Apr 2022 09:50 by federica.

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

Moderators: support
  1. Forum
  3. Discussions
  5. QuickOPC-UA in COM
  7. Reading, Writing, Subscriptions
  9. Filter subscriptions
Time to create page: 0.048 seconds