Tani - Historian for plant data

What a historian does

A historian is recording data over time. The time period can be long - very long, for many years. Later this can be used for forensic applications. Additionally a fast overview over the plant activities can be done. The frondend for these are trend views. OEE applications always are basing on data recorded with a historian.

Data con be stored into two destinations.

• Into memory.

  Memory recordings are often operated as a ring. This means that a small amount of recorded data is available. This allows you to determine run times, or briefly check what has run in the last quarter of an hour. Memory data is not saved permanently. If the machine is switched off with the historian, the data is no longer available after the restart.

• Permanently into files.

  Recordings on hard disks are permanent, they require a physical storage medium. This can be done on locally installed disks, or it can be disks on the network. You can also use any cloud storage like Dropbox, Google Drive, Azure or AWS for this purpose, a file access must be provided only. With hard disk data, you can make evaluations even after a long time. If damage has occurred, this data could be used to determine the cause of the damage. An example are tachographs or the black box in airplanes. Many settings are available for the files. So in regular time intervals in each case a new file can be used. Older files can then be moved to a separate medium, for example.

Of course, for one variable both are possible at the same time like a storage ring for short term data and long term logging to files.