State statistical summary data
- Last UpdatedNov 05, 2024
- 1 minute read
The Historian stores and retrieves values, where every value gets stored with some timestamp and associated quality. This triplet of value, timestamp, and quality is called VTQ and constitutes the smallest addressable piece of data in the Historian data model.
State summary statistics summarize the states of a value. Four different state value data types are possible: analog (integer), Boolean, string, and Null.
Note: Possible Boolean state values are 0 or 1. True or False strings are not supported.
A custom property state reference can subscribe to state statistics from the Historian as static text, an expression or reference, an aggregate function name, minutes, and state value.
The Historian returns the VTQ for one cycle of a specified state. The quality returned is always OpcQuality. The time returned is always the summary period start time. Value and Time differ based on the aggregate function.
The following table lists state historical statistical data that can be specified for a custom property.
|
State Statistical Data |
Description |
|---|---|
|
Average |
Average time a state occurred and completed within a summary period. A partial state within a summary period is ignored for an average calculation. (StateTimeAvgContained) |
|
Minimum |
Minimum time a state occurred and completed within a summary period. A partial state is ignored. (StateTimeMinContained) |
|
Maximum |
Maximum time a state occurred within a summary period. (StateTimeMax) |
|
Count |
Number of times a state occurred and completed within a summary period. A partial state is not counted. (StateCountContained). |
|
Percent |
Percentage of the summary period that a state occurred. (StateTimePercent) |
|
Total |
Total time a state occurred within a summary period. (StateTimeTotal) |