Data transfer to/from PI SDK and Matlab

Discussion created by rehanna on Sep 16, 2013
Latest reply on Sep 17, 2013 by Marcos Vainer Loeff

Hello, I have limited experience with the PI SDK and am new to vCampus so I apologize if I've posted in an inappropriate location or if my question has been answered in a different thread.  


I am trying to obtain data from the PI SDK using Matlab and have written the following code: 

sdk = NET.addAssembly('OSIsoft.PISDK');
sdkcommon = NET.addAssembly('OSIsoft.PISDKCommon');
sdktimeserver = NET.addAssembly('OSIsoft.PITimeServer');
pi_sdk =  PISDK.PISDKClass();
time_start = System.String('15-Sep-2013 11:00:00');
time_end = System.String('15-Sep-2013 11:01:00');
PI_DATA.PV = PI_POINT.PV.Data.RecordedValues(time_start,time_end);

The PI tag from which I am grabbing records 1 sec data, but for a given minute generally 30-37 data are returned, not 60.  Similarly, with a separate PI tag that records 1 min data, 2-6 data are returned, not 1.  Any insight into the nature of these data grabs or into better use of the start/end times would be helpful as I'm unfamiliar with the way the data is stored in PI.


Thank you,