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OPC-UA Alarms & Conditions

QuickOPC gives you access to OPC UA functionality described in Part 9 of the OPC Unified Architecture Specification, also known as Alarms & Conditions. This part shares many common concepts and objects with the Generic/Data part, making it easy to understand, and also easy to create applications that mix multiple functionalities in one project.

If you need OPC Alarms & Events for OPC "Classic" (COM-based), click here - QuickOPC supports it too.

What Can You Do?

With QuickOPC, you can:
  • Discover (browse) OPC servers (applications) on the computer and on the network.
  • Browse the address space of the OPC server; you can also browse for event sources and notifiers..
  • Subscribe to OPC UA events, and possibly later change the parameters of the subscription, or unsubscribe.
  • Receive event notifications, separately from data change notifications, and handle them using event handlers, or callback methods.
  • Specify event filters with your subscriptions, including the so-called Select clauses and Where clauses. It is possible to use pre-defined clauses to cover the most common cases.
  • Costruct Select clauses using a combination of filter operands and filter operators.
  • Use a builder class to create Select clauses (a form of expressions over OPC attributes) easily.
  • Refresh condition states (QuickOPC initiates the Refresh automatically, by default).
  • Enable and disable conditions, and apply comments to them.
  • Respond to alarm dialogs.
  • Acknowledge and/or confirm condition instance states.
  • Shelve and unshelve alarms. Timed shelve, or one shot shelve, are both possible.
  • Display ready-made browsing dialogs and use browsing controls with rich user interface.


If you need to match the client capabilities against requirements expressed in terms of OPC UA profiles, see OPC UA Profiles in the documentation for the full list of profiles supported. You can also consult lists of OPC UA Services and OPC UA Security Policies supported.

Useful links: Documentation / Examples / Knowledge Base

OPC-UA Alarms & Conditions Example in C#

The code below (in C#) shows how to subscribe to event notifications and display each incoming event using a callback method that is provided as lambda expression, using QuickOPC:

// The callback is a lambda expression that displays the event 
    "opc.tcp://",     UAObjectIds.Server,
    (_, args) => Console.WriteLine(args));

No other product can do this in such a clear and concise code, in a single statement!

Try It

Of course, more examples come with the product. And, all OPC UA Alarms & Conditions features of QuickOPC can be used from many languages and tools - not just C#, but also VB.NET, VB6, C/C++. VB6, PHP, Excel (VBA), Delphi, Perl, Python and more.


Footnote & required disclosure: QuickOPC (including its Options) is a software development kit (SDK) for development of OPC clients and subscribers. Installing QuickOPC or its Options does not change system settings.