iphist:index
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iphist:index [2021/06/25 15:41] – [INTERP] su | iphist:index [2021/09/09 09:14] – [IPHist - IPHist replication] su | ||
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===== Introduction ===== | ===== Introduction ===== | ||
+ | |||
+ | Intelligent Plant' | ||
+ | |||
+ | For many data sources (such as Modbus, MQTT, and more), it is possible to automatically forward tag values from the source using a simple one-click configuration. | ||
+ | |||
+ | Additionally, | ||
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+ | ===== Data Query Types ===== | ||
+ | |||
+ | IP Historian supports a number of different types of data queries. | ||
+ | |||
+ | ==== Snapshot ==== | ||
+ | |||
+ | Snapshot queries return the current values of the tags polled. | ||
+ | |||
+ | |||
+ | ==== Raw ==== | ||
+ | |||
+ | A raw query returns the unprocessed data for a tag i.e. the actual data points persisted in the historian' | ||
+ | |||
+ | Raw queries are generally not advised as they are likely to return a bulky result-set that may well be cropped by size constraints. In the majority of cases, a plot or aggregated data query can return a data set that is acceptable for the task at hand. | ||
+ | |||
+ | |||
+ | ==== Plot ==== | ||
+ | |||
+ | Plot queries return a best-fit data set for a given query time range and level of granularity, | ||
+ | |||
+ | |||
+ | ==== Values-at-Times ==== | ||
+ | |||
+ | A values-at-times query is used to retrieve the value of a tag at specified points in time. IP Historian will return the closest raw value at or before each specified sample time. | ||
+ | |||
+ | |||
+ | ==== Aggregated ==== | ||
+ | |||
+ | Aggregated queries can be used to perform ad hoc processing and filtering of raw historical data based on a query time range and sample interval. IP Historian supports a number of aggregation functions, as described below: | ||
+ | |||
+ | == ANNOTATIONCOUNT == | ||
+ | |||
+ | Groups the raw data for a tag into buckets using the specified sample interval and returns the number of annotations defined on a tag in each bucket. | ||
+ | |||
+ | == AVG == | ||
+ | |||
+ | Groups the raw data for a tag into buckets using the specified sample interval and computes the mean value of a tag in each bucket. | ||
+ | |||
+ | == COUNT == | ||
+ | |||
+ | Groups the raw data for a tag into buckets using the specified sample interval and returns the number of raw samples in each bucket. | ||
+ | |||
+ | == DELTA == | ||
+ | |||
+ | Groups the raw data for a tag into buckets using the specified sample interval and returns the signed difference between the first and last raw samples in each bucket. | ||
+ | |||
+ | == INTERP == | ||
+ | |||
+ | Groups the raw data for a tag into buckets using the specified sample interval and interpolates a value at each bucket start and/or end time using the values from the previous and current buckets. | ||
+ | |||
+ | == MIN == | ||
+ | |||
+ | Groups the raw data for a tag into buckets using the specified sample interval and returns the minimum value from each bucket. Note that the original raw samples are returned, so the values are the " | ||
+ | |||
+ | == MAX == | ||
+ | |||
+ | Groups the raw data for a tag into buckets using the specified sample interval and returns the maximum value from each bucket. Note that the original raw samples are returned, so the values are the " | ||
+ | |||
+ | == PERCENTBAD == | ||
+ | |||
+ | Groups the raw data for a tag into buckets using the specified sample interval and computes the percentage of raw samples in each bucket that have a quality flag set to " | ||
+ | |||
+ | == PERCENTGOOD == | ||
+ | |||
+ | Groups the raw data for a tag into buckets using the specified sample interval and computes the percentage of raw samples in each bucket that have a quality flag set to " | ||
+ | |||
+ | == RANGE == | ||
+ | |||
+ | Groups the raw data for a tag into buckets using the specified sample interval and returns the absolute difference between the first and last raw samples in each bucket. | ||
+ | |||
+ | == STDDEV == | ||
+ | Groups the raw data for a tag into buckets using the specified sample interval and returns the standard deviation for each bucket. | ||
- | =====Historical Vs. Snapshot===== | + | == TAVG == |
+ | Calculates a time-based rolling average for a tag. | ||
- | =====Functions and Aggregations===== | + | == VARIANCE |
- | ==== SNAPSHOT ==== | + | Groups the raw data for a tag into buckets using the specified sample interval and returns the variance for each bucket. |
- | Snapshot queries are used to request the current value of an instrument (or instruments). For example, you might have a digital thermometer that you can poll to find out what the current temperature is. When you perform a snapshot query, you don't need to specify any parameters other than the names of the instruments that you want to poll. | ||
- | ==== AVG ==== | + | ==== Annotations |
- | Returns the average value at interavals defined by the query interval ie adds up all values | + | IP Historian allows annotations to be recorded against tags at specific points in time. Annotations can be used to track or highlight events a tag value exceeding an operating limit, an action taken as part of a workflow, |
- | ==== MIN ==== | + | |
- | Returns the minimum value for each interval (the lowest value observed in that time) | ||
- | note, with the two filters applied - there is no loss in resolution of the minimum value, that minimum is still recorded and delivered. | ||
- | ==== MAX ==== | ||
- | Returns the maximum value for each interval - as above this is the maximum observed value in that interval | + | ==== Specifying Query Time Ranges ==== |
- | ==== STDDEV ==== | + | As part of the Data Core data connectivity layer, IP Historian can accept query time ranges specified as both absolute timestamps (using standard ISO 8601 formatting), |
- | Returns the standard deviation of the values in each interval | ||
- | ==== INTERP | + | ===== Archiving Model ===== |
- | returns an interpolated value for the exact time of the interval (taking the value recorded before and after the interval) - if interp is used at a simliar rate to the original | + | IP Historian supports multiple indexing models depending on the requirements |
- | ==== PLOT ==== | + | |
- | Plot is a special type of function that returns the minimum number of data points (for a given set of parameters) required to graphically plot an accurate time-series trend. This will be up to 4 points per interval where the values are: Max, Min, First, Last. | + | * "One Big Index" - optimised |
+ | * "Index per Day/ | ||
- | Consider | + | When recording process data, we normally recommend "Index per Month" as the optimal indexing period. |
- | {{ : | ||
+ | ===== Backing Up ===== | ||
- | ==== RAW ==== | + | Indexes can be backed up and restored on another IP Historian instance. |
- | A raw query returns the unprocessed data for a tag. That is, the actual data points persisted in the historian. Note that this is unlikely to be same as the rate at which a sensor data emits readings as a correctly configured historian will be exercising Compression and Exception (see above). | ||
- | Raw queries are generally not advised as they are likely to return a bulky result-set that may well be cropped by size constraints. If connecting to a Process Data Historian, it is far more efficient to request “Get Processed Data” with an “INTERP” function instead. | + | ===== System Requirements ===== |
+ | See [[app_store_connect: | ||
- | =====Specifying Date-Ranges===== | + | However, note the system requirements should be adjusted for the particular use-case of the historian. If you intend to support historization of large data volumes and intensive data queries, a more powerful spec is required. Please consult with the Intelligent Plant support team for detailed guidance. |
- | Historical data queries will expect a date-range. | + | ===== Configuration Best Practice ===== |
- | For '' | + | Details |
- | Relative values can be specified using '' | ||
- | =====Archiving Model===== | ||
- | =====Backing Up===== | + | ===== Licensing |
+ | When connecting IP Historian to the Industrial App Store, there is no licensing cost. An initial 1000 tag licence is supplied, but can be increased free of charge by client request. | ||
- | =====System Requirements===== | + | IP Historian deployments that are not directly connected to the Industrial App Store (e.g. deployments on a PIN or PCN) require a paid-for licence that is issued in 1000 tag increments. |
- | =====Licensing===== | + | =====IPHist - IPHist replication===== |
+ | Connections can be setup in datacore to provide reslient transfer of historical data between IPHist instances. this means that a loss in connectivity will not result in a permanent loss of data on the remote IPHist to the datasource. that data will be back filled, and consistent. | ||
+ | For further information regarding replication and data resilience, contact support@intelligentplant.com. | ||
+ | =====Other historian - IPHist replication, |
iphist/index.txt · Last modified: 2022/08/29 12:05 by su