HistorianRetrievalMode Enumeration
- Last UpdatedAug 21, 2026
- 3 minute read
Represents a retrieval mode to be used.
'Declaration
Public Enum HistorianRetrievalMode
Inherits System.Enum'Usage
Dim instance As HistorianRetrievalModepublic enum HistorianRetrievalMode : System.Enum public enum class HistorianRetrievalMode : public System.Enum | Member | Description |
|---|---|
| BestFit | For the "best fit" retrieval mode, the total time for the query is divided into even sub-periods, and then up to five values are returned for each sub-period:
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| Counter | The purpose of the counter retrieval mode is to use a tag's rollover value to calculate and return the delta change between consecutive retrieval cycles. |
| Cyclic | Cyclic based retrieval is the retrieval of stored data for the given time period based on a specified cyclic retrieval resolution, regardless of whether or not the value of the tag(s) has changed. |
| Delta | Delta retrieval, or retrieval based on exception, is the retrieval of only the changed tag values for a tag(s) for the given time interval. That is, duplicate values are not returned. |
| EndBound | The EndBound retrieval mode allows you to retrieve the end point (VTQ) for a given timeReturns a point after the datetime provided in the query |
| Full | Full retrieval mode, which can be used for all tag types, can best be described as delta retrieval without deadband checking. For full retrieval mode, all stored values will be returned, regardless of whether a value or quality has changed since the last value. |
| Integral | The integral retrieval mode calculates the values to be returned at retrieval cycle boundaries by integrating the graph described by the points stored for the tag. The integral retrieval mode only differs from the time-weighted average retrieval mode in that a scaling factor is applied. |
| Interpolated | For the interpolated retrieval mode, linear interpolation is used to calculate the value to be returned for each cycle boundary. |
| MaximumWithTime | The minimum value retrieval mode allows you to retrieve the minimum value that occurs for each set of data values within a retrieval cycle. |
| MinimumWithTime | The minimum value retrieval mode allows you to retrieve the minimum value that occurs for each set of data values within a retrieval cycle. |
| RawExpression | For automation only. Retrieve primary data values for aggregate expressions with single tag as param. |
| RoundTrip | The RoundTrip retrieval mode performs calculations on state occurrences in the Value column within cyclic periods specified by the client. The RoundTrip mode uses the time between consecutive leading edges of the same state for its calculations. |
| Slope | The purpose of the slope retrieval mode is to calculate and return the slope of a line drawn through a given point and the point immediately before it, thus expressing the rate at which values change. |
| StartBound | The StartBound retrieval mode allows you to retrieve the starting point (VTQ) for a given timeReturns a point on or before the datetime provided in the query |
| TimeWeightedAverage | For the time-weighted average (TWA) retrieval mode, a time-weighted average algorithm will be used to calculate the values to be returned for each retrieval cycle. |
| UnsummarizedStatus | The UnsummarizedTimes retrieval mode allows you to retrieve the unsummarized status at given time |
| ValueState | The value state retrieval mode. The time-in-state retrieval mode returns the amount of time that a tag has been in a particular state per each retrieval cycleValueState retrieval is only defined for integer tags, discrete tags (or tags changed to discrete using ToDiscrete, string tags and state summary tags. For other types of tags no rows are returned. |
System.Object
System.ValueType
System.Enum
ArchestrA.HistorianRetrievalMode