AnsweredAssumed Answered

PIACE get value at specific time. Where are my values coming from, they are not in the archive.

Question asked by parasyn on Apr 24, 2015
Latest reply on Apr 27, 2015 by Eugene Lee

I have time stamps in the pi archive:  (all dates are DD/MM/YYYY)

01/03/2015 00:00 value = 2

09/04/2015 12:45 value = 3


In PiACE I am doing calculations every 15 mins and getting the PI values at the exact 15 min mark.

To do that I have been setting the exetime of the pi point to the time I am calculating then get the value.  This appears to be working perfectly for everything I have tested except for one module that I am trying to test.


If I set the time to be 01/03/2015 08:00 it is returning the value of 2.  I suspect it is doing this because it is the value in the archive prior to this datetime I have specified?  Maybe exetime works like that … if it cannot find a value at the time specified it returns the previous known value in the system or maybe I have a problem with my archive or something else more sinister which is why it is retrieving values when there is no data in the archive.


or maybe when I try to reset the datetime I need to clear value first and then set the datetime??