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Datalink result is unchanging despite base data changing

Question asked by jeffshaw on Jan 5, 2017
Latest reply on Jan 5, 2017 by tmcmanus

Hello, I am using Datalink to pull data from a collective using sampled data with expressions.  The expressions evaluate OK most of the time are return actively changing results based on the root tag data changing.  However, there are often times - a number of days sometimes, where the same expressions return an unchanging result set as seen below.  This is datalink 5.0.0.

 

I've also attached some screenshots from the archive editor for the two tags used in the expression for column B during the timeframe when the datalink results are unchanging that shows actively changing advise data.   What fundamental am I missing here?  I've tried changing the root path to the secondary server in case there was some failover and non-merging of the data, but I get the same behavior.   I'd love any advice.

 

In this case, I am pulling voltage and current data, and the expression is:

 

((Float("1.0")*'Average_Current'*Float("1.0")*'Average_Voltage'))*0.91*SQR(3)/1000

 

Thank you in advance for sharing your insights and experiences.

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