Alignment between multiple tags during event subscription?

Discussion created by BenSmith on Aug 22, 2014
Latest reply on Aug 27, 2014 by skwan

Hello there,


We are using PI SDK for getting the aligned data between multiple tags/Points using interpolated option for archived data. Now we wanted do the same kind of alignment for the real-time data in event subscription option.   But we dont have clue how we can achieve the aligned data between different tags, because all the events will be having different timestamps. Can you guide us to follow the right direction?  Consider the following example for better understanding, but ideally we need to create a sample/row of data by combining multiple tags/Pipoints.  


Two process parameters are being measured parallel,  pH at every 2 seconds and Temperature at every 3 seconds, So event being generated at different intervals like below table.




So at what point of time, we need to create a sample which contains aligned data between two points?  What is the ideal scenario in the process industry?




Next question is about spectra data which is usually floating point array of having 1000 lengths or more.  How PI handles these kind of array data? If i'm not wrong, ideally these should have same timestamps.  So how these data is stored and  retrieved?