AF Attribute Data as a Relative Timestamp

Discussion created by s.grainger on Dec 16, 2010
Latest reply on Dec 22, 2010 by skwan



I am attempting to compare a few values in AF and I'm wondering if I'm going about it wrong.


My situation is that I have retrieved values from a CMMS Database and have pulled them into AF Attributes.  These are two attributes for 'Last Maintenance Date' [Date/Time] and 'Mean Time Between Failures' [Hours]. 


I am attempting to use daily runtimes [hours] captured in PI (also imported to AF attributes) to compare the cumulative runtime of a piece of equipment SINCE the last maintenance date to the mean time between failures.  As it stands now, the PI Runtime generates a value every 24 hours, reporting for how many hours it was on over the day (therefore requiring a sum of runtimes over the course of multiple days).


So far I have been unsuccessful.  I have attempted to create a PI Point attribute that references the PI Runtime Attribute, pulling a 'Total' over a time range of '*' to the value of 'Last Maintenance Date' - but I do not know if this functionality exists.


Is there another (better) way to approach this problem, or does this functionality exist, and I am using it incorrectly?


Any guidance would be appreciated, thank you!