Filling History Gaps for History Transport Managers

To fill history gaps which occurred for a history transfer process which is overlooked by a History Transfer Manager, a second history transfer process is needed. While in general no History Transporter objects should be created directly (but only through History Transfer Controller or History Transport Manager objects), backfilling is an exception to this rule.

Creating a History Transporter Object

To create a new History Transporter Object …​

1 Connect DataStudio to the Core on the "Transferring" machine.

2 In the I/O Model, right-click the Connector object for the "Source Historian" and select Admin  New  History  History Transporter.

3 In the Create Object wizard, enter a Name.
In this example the object is called Backfill History Transporter.

4 Click Create to close the Create Object wizard and create the new History Transporter object in the I/O Model. It should be a sibling object of the History Transfer Controller or History Transport Manager for which it should backfill the history gap.

5 For the next steps, select the newly created History Transporter object in the I/O Model to display its properties in the Properties Panel.

Matching the Alternative Interface Configuration

If the original History Transport Mangager object has any properties of the Alternative Interface property compound configured, set these properties on the "Backfill" History Transporter object to the same settings.

Tag Specification

The tags for which history gaps should be filled, need to be specified in the Tag Configuration table property in the Common property compound of the "Backfill" History Transporter object.

The objects representing the tags have been created automatically by the original History Transport Manager. They are located underneath this History Transport Manager object, inside the path specified in the Folder Hierarchy property.

Whenever the data of a tag object changes, it’s automatically forwarded ot the GTSB and therefore to the Target Historian.

To specify the tags for which historical data is to be filled …​

1 Locate the tags which have been created by the regular history transfer process in the I/O Model.

2 Select the parent object of the tags, right-click and select Copy full path from the context menu.

3 In the I/O Model, select the Backfill History Transporter Object.

4 In the Property Panel, click on the table icon for the Tag Configuration property to open the TableGrid Display.

5 For each relevant tag …​

  1. In the NodeName colum, paste the previously copied Full Path to the tag’s parent object.

  2. In the ExternalID column, enter the Object Name of the tag object, since the value for the Object Name property was automatically set, based on the tag ID on the Source Historian system.

  3. In the ObjectName column, also enter the Object Name of the tag object.

6 Click OK to close the table.

Timespan Specification

The timespan for which datapoints are to be transferred for the specified tags is defined in the Depth property in the Common section of the "backfill" history transporter object.

Starttime and endtime are separated by a colon and both points in time are specified in relation to <now> which is symbolized by '*'. For example, a Depth of '*-1d2h :*-23h' would mean the three hours from 26 hours ago to 23 hours ago.

Disabling the Transfer of Up-To-Date Data

Since up-to-date data is not relevant for filling gaps in the historical data, unselect the checkbox for the Transfer UTD property.

Starting the Backfill Process

To start the backfill history transfer, set the Processing Mode property of the the History Transporter object to Continuous and click Apply for the Property Panel.

Expand the Diagnostics property compount of the Backfill History Transporter object to see the backfill at work. As soon as the History Progress bar shows 100% all data points for the specified tags and timespan have been sent to the target historian.

The backfill history transfer will transfer all datapoints which exist on the Source Historian system for the specified tags and in the specified timespan. This may result in duplicate data on the Target Historian system unless it provides some functionality to prevent this.

Finishing the Backfill Process

When the backfill history transfer process has finished, set the Processing Mode property of the the History Transporter object to Configuration and click Apply for the Property Panel.

Optimization Options

The History Transporter object offers a lot of options which can be used to optimize the efficiency of the backfill history transfer process as well as to control the burden this process creates for the system. These options are addressed in detail on the page regarding the Advanced History Transporter Options.

As for history transfer processes using History Transport Manager objects all changes for the configured tags are automatically written to the GTSB and therefore to the Target Historian system, no Refetching process is needed to deploy the backfilled data to the Target Historian.