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maxCount restriction for stremasets call in PI Web API

Question asked by Paurav Joshi Champion on Apr 18, 2016
Latest reply on Apr 21, 2016 by Paurav Joshi

While getting lots of data of PI tag we encountered similar error, and the solution also lies with some of the tuning parameters in PI Data Archive. To get data from PI tag, we use streams in PI Web API call.

 

Here problem statement is that we want to fetch data from all elements below specified root in AF hierarchy for the duration of 30 days. For example, we have 35 turbines and each turbine has 43 attributes. We want to retrieve 30 days data for all attributes' of each turbine which is around 15-20 million data.

 

So we think the best way is to use stream sets as in definition only it said to be meant for bulk data retrieval.

We have some doubts here:

  • According to document, while specifying the GET streamsets/{webId}/recorded we can specify maxCount. What value of maxCount should be defined to get all the events. 0 is definitely not the value, I checked that :

maxCount

The maximum number of values to be returned. The default is 1000. A value of '0' means that all of the events within the requested time range will be returned.

  • In case of fetching data via stream in Web API, the maxCount number dependent on maxArcCollect. Here, the error come like:

"Parameter 'maxCount' is greater than the maximum allowed (2000)."

How this limit has been decided? Is there based on any tuning parameter?

 

Kindly let us know how can we retrieve this data via PI Web API.

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