Historian Module (Concept)

The Historian Module stores tag values with timestamps in SQL or time-series databases, enabling historical data analysis, trending, and reporting for industrial processes.



On this page:



Historian → Tutorial | Concept | How-to Guide | Reference


Understanding Industrial Data Historians

Industrial processes generate continuous data streams that require storage and analysis. The Historian Module captures this time-series data for:

  • Trend Analysis - Visualize patterns and anomalies over time
  • Performance Optimization - Compare current vs historical operation
  • Regulatory Compliance - Maintain required data retention
  • Root Cause Analysis - Investigate past events and issues
  • Reporting - Generate production and quality reports

Key Concepts

  • HistorianTag: Tag configured for historical data storage with specific collection rules
  • HistorianTable: Group of tags with shared storage settings (sampling rate, retention, triggers)
  • StorageLocation: Database destination for each historian table (SQL, external historians, custom)
  • Trigger: Condition that determines when to store data (on change, periodic, event-based)
  • Deadband: Filtering to prevent storage of insignificant changes
  • Store and Forward: Buffering system ensuring no data loss during connection failures

What It Does

The Historian Module provides comprehensive data archiving:

  • Stores time-series data from any tag in the system
  • Connects to multiple databases simultaneously
  • Provides data retrieval for trends, reports, and analytics
  • Manages data retention and automatic purging
  • Handles store-and-forward during database outages
  • Supports both SQL and specialized historian databases

Configuration Workflow

Historian Module Configuration Workflow

Step

Action

Description

Select Database

Choose storage destination

Default SQLite or external database (PI, Canary, InfluxDB)

Create HistorianTables

Define storage groups

Set sampling rates, triggers, and retention policies

Add HistorianTags

Assign tags to tables

Map tags to appropriate storage groups

Configure Triggers

Set storage conditions

On change, periodic, or condition-based storage


Runtime Behavior

Data Collection

The module subscribes to all configured historian tags and evaluates trigger conditions. Data is stored to designated locations based on table settings, with automatic buffering if databases are temporarily unavailable.

Data Retrieval

Scripts, displays, and reports request historical data through the Historian module's query interface. The TrendChart component provides built-in visualization of time-series data.

eature Highlights

  • Native Integration - Canary, OSIsoft PI, InfluxDB, and other major historians
  • Store and Forward - No data loss during network interruptions
  • Timezone Handling - Automatic timezone and daylight saving time management
  • Built-in SQL Engine - Embedded historian for SQL databases
  • Web Monitoring - Browser-based historian status and trending
  • Flexible Schemas - Standard or normalized table structures
  • Compression Options - Deadbands and deviation filtering


In this section...