Dear All,
I' working on issue a PHV trends , where the operator cant go back in trends for any parameters for 2 months back but for some reason the trend history before more than 2 months available in PHV so there is a gab in the trends.
when i checked the Historian setting for the workstation the maximum historian size to 600 MB and minimum time span enabled to 60 days but the data set time span not enable. The data set size was 600 MB and the data set export enabled.the historical data entry was not enabled. i have several questions:
thanks
Andre Dicaire
In reply to Andre Dicaire:
In reply to Haitham:
When you create the Extended Data set, it will appear in the list of data sets shown in the Administration tool indicating the type is Extended and Backup Status is Backed Up.
If it does not appear in the list, it would have indicated a message as to why the Extended data set was not created. Note on the left that the Primary location where the Active, Current and Extended Data sets reside. Your Export files are likely in a backup location.
When configurating the Historian, you define the "max" size of the history space on the hard drive with a maximum size of 10Gb, (10,000 Mb). Along the bottom of the Admin tool, it indicates the number of objects and the Free Space for datasets. The Free space value is based on your configured max size minus the Active and Current datasets. The extended Datasets don't apply to this free space limit. In the example above, the Active dataset is 23 Mb and my max size is 600 Mb on this computer, and the free space is 600 - 23 = 577 Mb. So adding an Extended Data set will not fail due to the configured history size. When free space approaches 0, the oldest Current Data set will be exported to allow a new Active Dataset to be created as needed. Your overall disk space on the computer is managed by you and should be verified prior to creating extended data sets to ensure there is enough disk space.
If you were successful in creating the data set, verify the "size" is consistent with your other data sets. Compare the time span to other data sets and the Size should be proportional to the size based on time span. If your new Extended dataset has a very small size, it may not contain the data you expect and so you still observe a gap at runtime.
As for the message you see on the other system, that is consistent with the Historian not being enabled on the computer you were running the Admin tool on. Check in Explorer that the computer has the Historian enabled and that it is the continuous Historian. If the system has the Advanced Historian or the Legacy historian, these are PI data historians and are managed with external PI Administrative tools, which are mostly command line level.