Overview
The Historian module uses the classical table system to organize data. With the Historian Tables, you can define generic characteristics that will apply to all Tags linked to each table. Thus, you can customize settings such as table name, data type, and data lifespan, providing advantages in potential database architectural migrations.
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Understanding Historian Tables
With the Historian Tables, you can configure settings to specify the Tag's Archive Location and define how and when the associated Tags will be archived.
In order to streamline the table creation process across different database types, it is feasible to define generic characteristics. These characteristics will subsequently be employed for table creation in the selected database, designated as ArchiveLocation. This procedure can also be independently conducted directly within the Database Management System (DBMS) in use. The introduction of this abstraction layer enables users to customize settings such as table name, data type, data lifespan, and so forth. This not only facilitates the automatic creation of the table but also provides numerous advantages from the perspective of potential database architectural migrations.
Historian Tables encompass the organization of tags read from Historian archives, arranging them systematically into Logical tables. These tables play a defining role by specifying the Target Archive database and settings, dictating when and how a specific group of tags is archived.
Definition
Historian Tables constitute a structured organization of tags from Historian archives, logically arranged into tables with defined settings for archiving within a specified Target Archive database.
Purpose
Provide user convenience with a configuration interface that encompasses all databases supported by the software.
Function
Automate the process of creating Historian tables in the database and define how and when groups of tags and properties will have their values recorded.
Operation
In operation, Historian Tables define the criteria for archiving, including the Target Archive database and specific settings, establishing a comprehensive framework for the storage and retrieval of tagged data.
Application
Historian Tables find application in the structured organization and storage of tagged data within the Historian system.
Usage
To use Historian TablesOn this page:
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Historian Tables Configuration
The Historian module creates a default HistorianTable using Dataset-TagHistorian SQL as the Target Database, with an additional HistorianTable being created if the Canary Historian is enabled. This setup offers a range of flexible options to choose from when selecting and configuring the target database for your solution's specific needs.
The HistorianTable settings allow you to define rules for saving the tags connected with it. You can set triggers such as a time deadband, specifying the minimum interval between saves, and a lifetime value, determining how long saved tag values will be retained. Note that certain options may be unavailable depending on the target database selected, so it's important to carefully consider your options.
Storing only the necessary data at the required frequency is a good practice to follow. You can use features such as deadbands, OnTagChange or Trigger events to organize your storage and save only what's required without overloading the system or slowing down data recovery.
HistorianTable configuration fields
New HistorianTables can be create with the NEW button, on Historian → Historian Tags, or editing the table on Historian → Historian Tables.
To modify History Tables, on Historian → Historian Tags, select the Table in the ComboBox and Config button, or editing the datagrid on Historian → Historian Tables.
Either using the Dialog view or datagrid view, the HistorianTable has the following configuration fields:
HistorianTable configuration properties | |||||||||||||
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Field | Description | ||||||||||||
TargetDB | Defines the Historian TargetDB. By default, SQL. Can only be changed while creating the HistorianTable. According to the Target option, some other fields on the configuration may be disabled | ||||||||||||
Table Name | Name of the HistorianTable object. For SQL databases, this name is also the table name inside the SQL DB. For other databases, this name is used as a logical grouping name.. | ||||||||||||
Auto Create | When checked, Historian module will check if this table is already created in your SQL DB. If not, a new one will be created. | ||||||||||||
Save on Change | When checked, whenever your Tags value has changed, the event to archive the tag is generated. | ||||||||||||
Trigger | Here you can define the event that triggers the archiving of all the tags in the HistorianTable group to the database. The trigger can be any tag, or any object or property from the objects namespaces. When you click on "…" ellipses button, a window will appear listing your Tags, Objects and Properties, allowing to select which one will act as a Trigger. | ||||||||||||
TimeDeadband | Enter the minimum logging interval. You must define in this format HH:MM:SS:MS (Hours, minutes, seconds, milliseconds). If left with zeros, this setting is not used. This is how long the system must wait after storing one value of a tag, before storing a new value. This field is used in conjunction with SaveOnChange option to avoid creating too many records in the database. Consider that you have a 5 seconds Deadband, the Deadband count will start when your Tag value changes. When Deadband count starts, any changes in Tag value in this range will not be saved on your DB if the time dead-end has not elapsed yet.. Your Tag’s value will only be saved in DB after TimeDeadband ends.
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Life Time | Here you can set in days how long the records will be stay on the Target Database. Every day, if the Historian Modules find data on the HistorianTables older than the lifetime, that data is automatically deleted. If its the value is 0 or blank, no automatic data deletion is executed. Data is no longer automatically deleted. | ||||||||||||
Save Quality | When checked, a column in your SQL DB store the Quality property of the Tag argon with the value. The quality level defines how much reliable is the Tag value and it follows the OPC standard specification. | ||||||||||||
Normalized | When checked, uses the Normalize table schema for SQL database, or the Standard schema otherwise. For more information on SQL database schemes refer to Archiving Process. | ||||||||||||
Value Columns Type | Select the Type for Value Columns used to store the tag values in the SQL database. This field can be edited ONLY when first creating the HistorianTable. Options:
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GetSamples Method | Name of a method defined on Script → Class to allow customization when retrieving data from this tables. | ||||||||||||
Description | Description for this HistorianTable object. | ||||||||||||
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