asoudek

AF Analytics - Advanced write back

Blog Post created by asoudek on Aug 31, 2016

Write the results of your expressions to a time other than the trigger time

A new feature in AF 2.7 (and later versions) is the ability to put the results of an analysis at a different time other than the execution time.  This is very useful in cases where some data, like lab information, gets entered but it refers to information for a previous time.  The calculation is done when the data comes in, but the results need to be written some previous time.  Another scenario is to a future point in time such as calculating new targets for the end of the month based on current production.  In this case, the value is calculated now and is timestamped at the end of the current month, relative to current evaluation or trigger time.

 

Writing back in time or to future time:

The laboratory density data comes in at 7 am, but it refers to the previous day period that is defined as 4 am to 4 am, in this case. The mass of material for the previous day period is calculated by the total of the volume of material for the previous day period times the density that was recorded at 7 am (but refers to the sample taken for the 4 am to 4 am period).  The calculation is triggered at 7 am and we now want to write the result back to 4 am.  So we used the Advaced… button and make the selection of the Output Time Stamp to be Relative to Trigger Time  typing t+4h, as shown in the Figure above.  Presto, problem solved.

o1.jpg

Note: you can use the same technique to write to future PI Tags, for example a new calculated target production.

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