History block notation and creation
- Last UpdatedMar 06, 2025
- 2 minute read
Each history block is contained in a single subdirectory in the circular storage directory.
The subdirectory name includes the date stamp of the AVEVA Historian computer at the time the block was created.
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For example, this is a typical history block name. It has three parts:
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A new history block is created when corresponding data is received that day. After that, new history blocks are automatically created with a time duration specified for that storage partition. .
History blocks can be created for data with timestamps in the future or the past.
Changing the history block time span does not take effect until after any previously-started blocks complete, even if a previously-started block is holding data with timestamps in the future. For example, if the time span is changed from "daily" to "hourly", the first hourly block will be for 12:00 AM to 1:00 AM on the following day.