Understand retrieval options
- Last UpdatedFeb 07, 2025
- 1 minute read
In all retrieval modes, you can adjust which values the historian returns by specifying retrieval options. The retrieval options are implemented as special parameters that you set as part of the retrieval query. This section explains each of these options. For an overview of which options apply to which retrieval modes, see Which options apply to which retrieval modes?.
Related Links
- Which options apply to which retrieval modes?
- Using retrieval options in a Transact-SQL statement
- Cycle count (X values over equal time intervals) (wwCycleCount)
- Resolution (values spaced every X ms) (wwResolution)
- About phantom cycles
- Value deadband (wwValueDeadband)
- Time deadband (wwTimeDeadband)
- History version (wwVersion)
- Interpolation type (wwInterpolationType)
- TimeStamp rule (wwTimeStampRule)
- Time zone (wwTimeZone)
- Quality rule (wwQualityRule)
- State calculation (wwStateCalc)
- Analog value filtering (wwFilter)
- Selecting values for analog summary tags (wwValueSelector)
- Expressions (wwexpression)