Trend worksheet

The Trend folder enables you to configure history groups that store trend curves. You can use the Trend worksheet to declare which tags must have their values stored on disk, and to create history files for trend graphs. The project stores the samples in a binary history file (*.hst), and shows both history and on-line samples in a screen trend graph.

The Trend worksheet is executed by the Background Task module (see Execution Tasks). It handles the saving of trend data to the history, but it does not display that data to the operator; the Trend Control screen object, available on the Graphics tab of the ribbon, must be created and configured in a screen in order to display trend data.

To create a new Trend worksheet, do one of the following:

To edit an existing Trend worksheet, double-click it in the Project Explorer.

Figure 1. Trend worksheet

The Trend worksheet is divided into two areas:
Use the Header parameters on this worksheet as follows:
Use the Body parameters on this worksheet as follows:
Note: The Trend task can accept only up to 240 tags in a single worksheet. If you manually configure more than 240 tags in the same worksheet, then the Trend task will generate an error when you run the finished project.
See also: