Working with the History Grid
In this How To section, we will cover working with data in a History Grid Display and introduce some of the features of the display.
To work through this example and to use the History Grid Display, you must first have archived data to work with. You can use history data from an I/O Item from an OPC Server or the Generic, Action or Data Holder Items that were created as part of the Infrastructure Hands On examples. For any of these items, the Value Storage Strategy, under the Archive Options, needs to be set to Raw History by selecting the checkbox in the Object Properties Panel.
Open a History Grid Display by right-clicking on a data item in the I/O Model tree and selecting Add item to… > History Grid > Last 10 Minutes.
The History Grid should look similar to the example shown below:
There are various ways to add more items to the same History Grid display:
Using the context menu of objects in the I/O Model panel: Right-click on the I/O object and select Add item to … > History Grid. The display that is currently visible is always the first option in the context sub-menu. Alternatively, use the Alt+Enter shortcut.
Drag and drop items into the History Grid Display: Select the desired item from the I/O Model and drag it into the History Grid Display, then release the mouse button.
To remove items, click on the drop-down menu in the menu bar for the History Grid Display and select the delete icon on the relevant item.
The time period displayed in a History Grid Display can be chosen when opening the display from a preset list (for example, the last 10 minutes or the last hour). However, an exact time period can also be specified and displayed at any point using the time period dialogue.
Click on the Select Time Period icon in the menu bar of the History Grid Display to open the Time Period Setting dialog.
Using this dialog, the following time settings for the History Grid Display can be changed:
Start Time - Absolute or Relative
End Time - Absolute or Relative
Interval - Length of Intervals to be fetched from the archive
Times can be entered into the Start and End time fields as absolute or relative values. To toggle between the two, click on the ←| icon above the respective fields. Click on the down arrow to set the time to "Now".
The total time period is displayed in the box between the two fields and can be altered to a value from the preset list.
system:inmation always retrieves intervals of data from the archive, and returns the requested aggregate based on the specified or calculated interval length.
The interval length can be specified in the Time Settings using the options in the central part of the dialogue:
Length Specify the length of each interval from preset list (1 sec, 1 hour, 1 day etc)
Count Specify the number of requested intervals, the length of the interval will then be calculated
Advanced Specify interval length in exact time units, number of requested intervals will be calculated
Default Interval length will automatically be selected based on the requested time period
Maximum Resolution Interval length will automatically be calculated based on requested time period and available numbers of pixels in the History Grid Display area
To configure the settings of a History Grid Display, click in the menu bar of the display.
For information on the General Settings section of the History Grid Settings configuration dialog, see History Grid Settings.
The History Source section of the settings dialog is used to specify the type of value which will be displayed as well as the Data Store used to store the historized data.
The History Source column is used to specify the historized item value or property value which will be displayed. By default, when an object is added to the History Grid, the historized Item Values (the V in VQT) are retrieved from the archive and displayed for the defined time period. Use the drop-down menu in this column to change the History Source to the historized values of other properties (for which the Historization Capability is enabled).
The drop-down menu for the Data Store column contains all data stores that are accessible to the Core. To access data stored in a remote Custom Data Store, use the drop-down menu in this column to select the relevant data store. Remote queries will only occur if a remote data store is selected. For more information on remote queries, see Query Routing.
When selecting a data store to query, only Custom Data Stores which the user has
LIST permissions for, will be displayed. For more information on permissions, see the Permissions section.
|Adjusting the settings in an individual History Grid Display will only affect the configuration of that specific display. To change the default settings for all History Grid Displays, go to the General Settings (shortcut F10). Alternatively, select the Save as Default checkbox at the bottom of the History Grid Settings window to save the configuration for new History Grid Displays. Enabling this checkbox will not change the configuration of pre-existing History Grid Displays.
|To view modified history data in a History Grid Display, the data must be stored in a local Custom Time Series Data Store v2. Modified history data will not be displayed for remote queries.
To configure the display of modified history data in a History Grid Display, enable 'Query Modified History' in the History Grid settings. In the menu bar of the History Grid Display, set the Aggregate Type to 'Raw Data'. Entries with modified history will be highlighted in the History Grid Display.
Hovering over any of the highlighted entries will display the modified history data at that timestamp in a table. This table can be moved around and pinned to the display.
The contents of the modified history table can also be exported as a CSV, a MS Excel file or a JSON.