Professional OPC
Development Tools

logos

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.

Determine active subscriptions

More
08 Dec 2015 13:59 #3720 by support
The first part can be achieved by maintaining a list of what you have subscribed to on your side (in one common storage), as it is completely under your control.

Not sure what you mean by the second part. If you refer to some kind of error handling, then be careful with that, and read the documentation first. In QuickOPC, a "subscribe" call indicates a permanent intent to become and stay subscribed - valid until a corresponding "unsubscribe" is called. In case of any errors, you will still receive a valid subscription handle. You just get an error notification (event or callback), and after a configurable period, QuickOPC will attempt to subscribe again - and so on. This approach automatically handles reconnections in case of errors caused e.g. by temporary network or server failures, server restarts, transient server misconfigurations, etc.

Best regards

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

  • Romaco123
  • Topic Author
  • Visitor
  • Visitor
08 Dec 2015 12:06 #3719 by Romaco123
Replied by Romaco123 on topic Determine active subscriptions
To optimize the Performance of our App we've decided to activate and deactive Variables in Groups. The Activation can be invoked async by different Tasks. It would be helpfull for us to have a Method to (pre)check if/which Variables/Groups are activated before invoking a (new) subscription.
The other reason is to be sure that all the Variables in the List (when calling SubscribeMultple..) were actually succesfully subscribed (or some were not).

Thank you
Best Regards

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

More
08 Dec 2015 10:49 #3718 by support
Not really, but please describe your use case (what are you trying to achieve), and I should be able to help you. Normally, such method should not be needed.

Best regards

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

  • Romaco123
  • Topic Author
  • Visitor
  • Visitor
08 Dec 2015 07:54 #3717 by Romaco123
Determine active subscriptions was created by Romaco123
Is there a Method available to retrieve a List of the currently active Variable-Subscriptions?

Thx

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

Moderators: support
Time to create page: 0.054 seconds