Rockwell Automation 1756-HIST2G FactoryTalk Historian ME 2.2 - Manual (Page 113)

6 • C OLLECTING D ATA
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Warning - a capacity percentage between 25 and 100 at which FactoryTalk
Historian ME will issue a warning. The default is 50%.
„
Critical - a capacity percentage between 25 and 100 at which FactoryTalk
Historian ME will issue a critical message. The default is 75%.
You can set FactoryTalk Historian ME to stop Data Collection when it reaches
this point. If you do not want Data Collection to stop, then you risk data
interruption when all archive files have been filled and the Data Collection
service begins overwriting the oldest data.
Exception Filtering
The purpose of Exception Filtering is for the Data Collection service to only collect
data you are interested in, rather than taxing the system by collecting a lot of data that
is not meaningful.
Exception filtering uses a deadband algorithm to determine whether to collect data
and store it in the FactoryTalk Historian ME archive. For each point, you can set
exception reporting specifications that create the deadband. The Data Collection
service throws out values that fall inside the deadband and does not pass it to the
archive.
You risk data interruption by checking the Stop Data Collection check box. Checking
this box automatically stops Data Collection if the critical capacity percentage is
reached.