As experts in data analysis, Pattern Discovery Technologies understands that capturing accurate data in your PI System is a must.
To manage the performance of the OSIsoft PI System, there are several tuning parameters that govern the collection and storage of data. Most significant among these are the parameters that govern the compression of the data captured at the interface and again when it is stored in the archive. If these settings are not correct, the archived data will not accurately reflect the original signal, or conversely, will store unnecessary volumes of data.
Since the PI Data Archive is the fundamental source for retrieving historical records, the exception and compression settings have a significant impact on the quality of the data stored and the performance of downstream applications relying on it. “Getting it right” is critical to the delivery of meaningful, useful information.
Particular attention should be paid to defining the Exception deviation (ExcDev) and Compression deviation (CompDev) settings in the PI System configuration.
This traditionally requires an intimate knowledge of the process combined with PI system administration capabilities. Given the overwhelming and time-consuming task of defining thousands of tags, users often rely on static “rules of thumb”, default settings or simple cut and paste exercises.
Sadly, this may not take into account the true characteristics of a specific signal, and a “set and forget” philosophy does not consider the dynamic nature and behavior of the data. Getting these parameters right and keeping them tuned throughout the life of the tag is critical to the quality of the data stored in the archive.
To aid with this, Pattern Discovery Technologies has developed an automated tag tuning and tag behavior identification software for the OSIsoft PI System called CompressionInsight™.
