Historical data


Historical data:

Down the sample project (HistoricalData_Hemelix.zip)

A Data Historian is a type of time-series database designed to efficiently collect and store process data from an automation system.

It allows operators and stakeholders to look at historical data for the plant. A Data Historian  is a software program that records and retrieves production and process data by time;

 Time series information is often displayed in a trend or as tabular data over a time range (ex. the last day, last 8 hours,

 last year). 

The historian data can then be used to display trends of process data on charts, create reports, or perform data analysis.

If we consider the historian as a whole software package then it can perform the following tasks:

=> Data collectors from the data sources such as a PLC, automation devices, OPC servers, etc.

=> The software processes the data and delivers the data to client applications. 

=> The software provides data for client applications for data reporting, charting, and analysis.


Historical data are data from earlier times that are stored in a database.

Arbitrary server symbols of the TwinCAT HMI (e.g. numerical values from the PLC) can be historized by the TcHmiSqliteHistorize extension. The extension saves the data in a ring buffer in an SQlite database. The interval at which the data are saved in the database can be defined for each symbol. The data are saved in the database only as long as the server is running. No historical data are written to the database if the server is terminated.


The historical data are displayed in an included control – the Trend Line Chart. The control enables the display of various historical data at the same time.

=>First add those Y-axis value which should be added to LineGraph

=>Then select LineGraphDescriptions


Next configure the LineGraphDescriptions

The tool bar is not shown by default, we need to tell to the framework.



Download the sample from the link given above.

See next our Linear Gauge example at https://www.hemelix.com/scada-hmi/twincat-hmi/hmi-localization/

Ask questions related to Hemelix sample code and design at Google group https://groups.google.com/g/hemelix