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Create a Phase Difference Alarm Event

Jun 7, 2012 at 4:59 PM

Hello everybody, 

I'm new with the last version of OpenPDC that manage  the alarms and I'm looking for some explanation if is possible. 

I see that is possible to setup a new alarm like a new measurement simply with the menu inside the Manage Menu. 

I  have setup alarms on threshold condition over and under and I have found the alarm measurement associated for each one of that alarms easy. 

What I want now is another thing, and in particular im trying to find the way to have an alarm  that make the Phase difference of two specific measurement.

Is necessary  to create a calculated measurement and then to setup an alarm on that measurement??

HOw can I create that??

Is there another way to do it ??


Thankyou in advice





Jun 29, 2012 at 9:41 PM
Edited Jun 29, 2012 at 9:42 PM

Cool - someone else was asking a question about writing an angle difference calculator - see this thread - perhaps you can collaborate with him. FYI - we'll be happy to post any solution to the open source code ;-)

In answer to your question - yes! The new alarming feature will alarm on any point of data - so if you create a calculated measurement of a phase difference you can easily setup an alarm off of that point...

Best of luck, sounds fun - let us know how we can help you here...


Aug 29, 2012 at 5:46 PM

How  is synchronization of these adapters handled? Do I simply add 'waitHandleNames' and 'waitHandleTimeout' to the out-of-the-box adapters so that these adapters wait? I imagine creating two new custom, calculated measurements with out-of-the-box adapters, perhaps creating a third measurement from some processing of the first two, and then creating an alarm on one or more of these measurements. How do I ensure that they all execute in order? That is, first 1 and 2, then 3, then 4. These adapters might be custom or out-of-the-box. The alarm creation page doesn't have a connection string; how can it be made to wait? Or is waiting implied by the measurement name, somehow knowing which custom adapter has created this measurement.

Aug 29, 2012 at 5:50 PM

To put a face on my previous reply, the first two custom measurements:

1. a measurement that is the slope of some  voltage angle (relative, wrapped?). This would be our custom adapter.

2. An average frequency (out-of-the-box)

3. Compare the first two measurements, ensuring that the slope corresponds correctly with the frequency vs basis frequency.

4. Alarm on the results of 3.