-
Re: Receiving archive data change events via AFDataPipe
Dan FishmanDec 15, 2014 5:20 PM (in response to rzandvliet)
. I know in the PIDataPipe class you specify the AFDataPipeType in the constructor. I'm not seeing this for the AFDataPipe.
My AFDataPipe I quickly pieced together is only picking up snapshot changes. My thoughts are that the AFDataPipe is only for snapshot/current value data change events. I'll see if I can get archive events through the pipe.
Regards,
Dan
-
Re: Receiving archive data change events via AFDataPipe
Rhys KirkDec 15, 2014 5:45 PM (in response to Dan Fishman)
1 of 1 people found this helpfulProbably because 'snapshot' and 'archive' are PI data archive concepts covered by the PIDataPipe and the AFDataPipe is reliant on the Attribute Data Reference's implementation of the Data Pipe. Perhaps as a developer we have to be specific when working with PI Points with archive data and use the PIDataPipe..?
-
Re: Receiving archive data change events via AFDataPipe
Roger Palmen Dec 15, 2014 8:09 PM (in response to Rhys Kirk)Digging around, it indeed clearly specifies this on the PiDataPipe class:
// Create a new data pipe for snapshot events
PIDataPipe myDataPipe = new PIDataPipe(AFDataPipeType.Snapshot)
But on the AFDataPipe, the constructor is indeed more easy to understand for anyone not understanding the bizarre difference between snapshot and archive:
AFDataPipe myDataPipe = new AFDataPipe()
The latter taken from: Using data pipes with future data in PI AF SDK 2.7
So i'll give my points to Rhys for the first and correct answer!
-
-
Re: Receiving archive data change events via AFDataPipe
rzandvliet Dec 16, 2014 7:05 AM (in response to Dan Fishman)Dan, Rhys and Roger,
for now I conclude that this is a "documentation bug" in the AFSDK.chm helpfile. When we want to assign for updates on archive events we have to use the pi points together with PiDataPipe and maintain the reference between the pi point and af attribute by ourself.
Regards,
Robert
-
Re: Receiving archive data change events via AFDataPipe
Marcos Vainer LoeffDec 16, 2014 11:04 AM (in response to rzandvliet)
1 of 1 people found this helpfulHi Robert,
Yes, the documentation needs to be fixed. I will foward this issue to the developers. From my understanding, the idea of not using the AFDataPipeType is due to the fact that AFDataPipes will monitor the snapshots and historical events automatically. Nevertheless, according to my quick tests, this will only occur on PI AF SDK 2.7. On PI AF SDK 2.6, it monitors only snapshot events. You can download the PI AF SDK 2.7 Beta and compare the results.
One last thing, I recommend you to use AFDataPipe instead of PIDataPipe. The development team is adding some cool features only on the AFDataPipe class so in order to avoid having to update your code in the future, just use AFDataPipe.
Hope it helps!
-
Re: Receiving archive data change events via AFDataPipe
rzandvliet Dec 16, 2014 12:18 PM (in response to Marcos Vainer Loeff)Marcos,
Thanks for updating. for snapshot we can use AFDataPipe, but we also need to retrieve archive updates. At the moment this can only be done via the PiDataPipe, because of installed PI Server and AF SDK versions . We will try to abstract the data retrieval layer from the rest of the application and change it when functionality becomes available and servers has been updated.
Regards,
Robert
-
-
-