Hello,
I will need more information to this - e.g. a sample project, or relevant pieces of code.

In general, the answer is that there should be no difference in QuickOPC behavior in the MVC application under IIS environment, and the subscription callbacks should fire as normal.

It should be noted, however, that (as far as the developer is concerned), the subscriptions are tied to the EasyXXClient instance they have been created on, and live until an explicit "unsubcscribe" is made, or the EasyXXClient instance is disposed of or finalized. In the context of typical Web applications, most code runs for the duration of the HTTP request/response processing for a page. Subscriptions should normally be long-lived, and it makes little sense to create/destroy them as part of page generation code. For them to make sense in the context of a Web application, you need some kind of global or at least long-lived EasyXXClient instance, on which the subscriptions can be made, and to which the event handlers can be tied (or callbacks handlers be specified). Do you have such long-lived instance in your code?

Best regards

Hello,

I'm developing an MVC 5 app on IIS 7 server. It seems that QuickOPC 5.34 doesn't fire the subscription callbacks in this environment. It works fine in normal desktop Visual Studio 2013 apps. Have you experienced that? How can i solve the problem?

Thanks