Historian
(Time-Series Data)
Introduction to the Historian Module
The Historian Module enables the storage of tag values and their corresponding timestamps in SQL databases or third-party time-series databases. This module is designed to streamline the collection and storage of data in its time context.
The Historian Module provides an out-of-the-box solution for archiving historical data without programming requirements. Although custom data logging procedures can be included in your solution using Scripts (.NET programming) and Datasets (SQL storage), the standard configuration tools of the Historian Module can fulfill most typical data logging needs.
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Key Concepts and Terms
HistorianTag
Tags whose values are stored in a HistorianTable, including dynamic references to external data.
HistorianTables
Groups Tags for historical archiving, defining settings for storage and retention.
StorageLocation
Defines where historian variables will be archived or read for charts and calculations.
Understanding the Historian Module
Module Features
- Embedded Canary Historian includes 100 free Canary historian tags with any license.
- The Historian Module works with the industry's major players (OSISoftPI, InfluxDB).
- Store and Forward function ensures your data will not be lost if the database is unavailable.
- Universal Time and Daylight Saving
Technical Overview
- You can define a Tag representing any data point you want to track over time.
- You can then add this Tag to a HistorianTable and configure settings like:
- How often to sample and store data (e.g., every second, every minute)
- Conditions to store the data (e.g., only when the value changes)
- Data retention policies (e.g., keep data for 1 year)
- The HistorianTable is associated with a StorageLocation, determining where the data will reside.
- The Historian Module regularly samples the tag's value and writes the time-series data to the designated StorageLocation according to the settings in the Historian Table.
Configuring the Historian Module
Configuration Workflow
Historian Module Configuration Workflow | ||
|---|---|---|
Action | Where | Comments |
Define the default TagHistorian SQL Database | Historian → Storage Location | By default, TagHistorian maps to a SQLite database named and located the same as the Solution itself, followed by the proper FileExtension. Learn more at Historian Storage Locations. |
If using Canary, modify the default target to the the Canary Historian | Historian → Storage Location | If using Canary, a connection with the local embedded Canary Historian is already included in the new solution. You can use that connection or modify it to connect to an external Canary System. Learn more at Historian Storage Locations. |
If necessary, add other Target Databases | Historian → Storage Location | If archiving or retrieving data from other Historian tools is necessary, add the connection in the Tag Providers. Mark the "Set as Historian Server" checkbox when creating the provider. Learn more at Historian Storage Locations. |
Create and Edit HistorianTables | Historian → Historian Tables | Add or modify HistorianTables, organizing how the Tags will be grouped for archiving and the Target Databases. Learn more at Historian Tables. |
Add Tags to the HistorianTables | Historian → Historian Tags | Connect Tags to the HistorianTables. Either by typing, browsing, pasting or any of the available import methods. Learn more at Historian Tags. |
Default Storage Location
When you create a new solution, the default database (Dataset.DB.TagHistorian) uses the embedded SQLite database provided in the Datasets Module. However, you can change the default option at any moment. Our platform lets you choose from various Historian options, including SQL databases, Canary Historian, or any available TagProvider powered by Historian tools. For a large quantity of tags, you can create HistorianTables to organize the storage into groups. Data is saved to a SQLite database by default. You can customize this to save in any other SQL database or external storage.
You can use multiple Historian system with the same solution. One, already pre-defined, its the platform built-in Historian using SQL databases. Additionally, you can other Historian engines to solution, using the TagProviders to Historian packages, or using Script extensions.
The table below describes the options available.
Database Option | Description |
|---|---|
SQLDatabase | You can use any SQL-style database defined in the object HistorianTag available on Datasets → DBs. |
Canary Historian | The platform includes an embedded Canary Labs Historian, and you can also use it with external Canary systems. Read more information on the Canary Labs page. |
TagProviders for Historians (InfluxDB, others) | The TatProviders feature allows you to seamlessly integrate with third-party products, which can act as native and fully integrated historian repositories. This feature enables you to use current interfaces or additional products, which can be incorporated using the driver toolkit. See the list of Historian TagProvider at the page UNS TagProvider Connections. |
Custom | There is a programming Interface that allows a class within the Script Module to act as the Historian repository, the call to archive and retrieved data are directly to that Script Class, and your solution has the complete freedom on customizing the responses to those requests. |
Using SQLite or other SQL databases
By default, the SQLite is selected when creating new solution, but our built-in SQL Historian can work with any other SQL database.
See at Dataset Module configuration how to set a different SQL Database for the TagHistorian connection.
For other TagProvider Historian targets, please refer to the UNS TagProvider Connections configuration to define and configure their use.
Working with the Historian Module
Runtime Execution
You can control the Historian module execution while running your solution. To Run, Pause, or Stop the Historian module directly from the platform, go to Access Runtime → Runtime Diagnostics to control the module.
When the Solution runs, the Historian Module operates in an isolated process on the server computer. The main procedures executed by the module include:
- Checking if a request to store from a HistorianTable was generated (by the Trigger or OnTagChange events).
- Archiving the data as needed.
- Synchronizing with remote archives if store and forward or redundancy is enabled.
- Replying to requests from displays and scripts on querying the archived data.
For deeper and advanced understanding of the execution see Historian Advanced Topics / Archiving Process
Monitoring the Historian Module Execution
When the solution is in runtime, the Historian Monitor menu provides a way to monitor real-time information related to the Historian Module operation.
→ Read more about the Historian Monitor.
Displaying TrendCharts
It is possible to display charts to analyze and compare historical and real-time data.
That is accomplished on displays using the TrendChart Control.
Querying Data on Scripts
This enables querying and retrieving data from variables and historical tables through scripts.
That is accomplish by using directly the methods and properties available on the Historian Runtime Attributes.
Historian Advanced Topics
Archiving Process
The Archiving Process is the process of receiving new data from Tags and storing it in databases defined by the StorageLocation. You can define different configurations to trigger storing actions based on your needs and database restrictions.
→ Read more about the Archiving Process.
Historian Runtime Attributes
Best Practices and Troubleshooting
Common Issues and Solutions
Data Not Being Stored
Check the HistorianTable configuration, Trigger or TagChange settings, and Target Database. Ensure the settings are correctly set up, and the database connection is valid.
Incomplete data
Ensure that the Historian module is started (IsStarted flag) and the archiving process is functioning correctly. Check for any error messages in the OpenStatusMessage string.
#Slow data retrieval
Enable the caching feature (EnableCache) to optimize performance when requesting large amounts of data.
Store and Forward Not Working
Verify if the Store and Forward feature is enabled and configured correctly. Check the local database and target database connections.
Database Connection Error
Check the database connection settings and ensure that the database is reachable.
Best Practices and Recommendations
To ensure the smooth operation of the Historian module, follow these best practices:
Use Descriptive Names for Historian Objects
Use clear and descriptive names for HistorianTables, tags, and other related objects.
Optimize Data Retrieval
Optimize data retrieval by enabling caching when working with large datasets.
Ensure Data Integrity with Store and Forward
Use Store and Forward to ensure data integrity in case of temporary database connection issues.
Plan Your Data Storage Strategy
Determine how much data you want to store and for how long you want to store it. It is important to plan your data storage strategy in advance so that you can optimize the historian module for your specific requirements.
Document Your Historians Configurations
Document your historian module configuration to make it easier to manage and maintain. This includes documenting data sources, data types, sampling rates, storage options, and performance optimizations.
Use Security Best Practices
Protect the historian module from unauthorized access by implementing security best practices such as user authentication, access control, and data encryption.
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