12.1 Orientation: The Historical Data Viewer Page

VTS Tutorial Lessons > Lesson 12: Logging and Plotting Tag Data

12.1 Orientation: The Historical Data Viewer Page

VTS automatically generates a Historical Data Viewer page when you create any new standard application. This Historical Data Viewer page enables you to plot both live and historical data for multiple tags on its graphs, making it easy for you or the operators of your system to review it and see trends over time. Figure 157 shows a labeled example of the Historical Data Viewer page.

Figure 157

The elements of the Historical Data Viewer page are described in detail below.

Pens

The term "pen" is used to describe the distinctly colored lines that plot data on the graph. Pens can be configured to display either live data in real-time or historical data that has been logged to disk. The tool bar contains a series of tools that enable you to manipulate the span of data being plotted.

Pen Legend

The pen legend is the vertical window appearing on the far left of the Historical Data Viewer page. This window displays information about each pen that is plotting data on the graph including details such as:

• The type of each tag (e.g. analog vs. digital).

• The name of each tag.

• The description of each tag.

• The color in which each tag's data is being plotted.

• The value for each tag.

The data displayed in the pen legend is modifiable; you can turn any of the above parameters on or off to expand or condense the amount of data displayed for a selected pen. This feature will be explored in 12.9 Modify Pen Data in the Pen Legend.

View Tabs

The view tabs on the Historical Data Viewer page enable you to toggle the page's display between the graph view (PlotView tab) and the tabular view (GridView tab).

Analog Plotting Area

The Historical Data Viewer page is comprised of two separate graphs; one for digital plots, and the other for analog plots. The analog plotting area appears at the top of the Historical Data Viewer page when one or more analog pens have been added to the pen legend. The y-axis for the analog plotting area displays the low and high scale ranges for each pen. The x-axis displays the configured time scale.

Digital Plotting Area

The digital plotting area appears at the bottom of the Historical Data Viewer page when one or more digital pens have been added to the pen legend. The y-axis for the digital plotting area displays the low and high scale ranges for each pen. The x-axis displays the configured time scale.

Figure 158 illustrates the positioning of the analog and digital plotting areas.

Figure 158

Tool Bar

Along the top of the Historical Data Viewer page is a tool bar featuring a series of tools that enable you to manipulate the way in which tag data is displayed on the graphs.

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The tool bar features the following tools (from left to right):

Pen Group Selector: The pen group selector drop-down list displays the names of the pen groups that have been configured for your application, and enables you to load a pen group simply by selecting it.

Tag Selector: The Tag Selector button opens the Tag Selector dialog from which you can choose the tags whose data you wish to plot.

Specifically, the Tag Selector enables you to perform the following tasks:

• Add pens to the graph.

• Remove pens from the graph.

• Save pen groups.

• Delete pen groups.

• Edit the parameters for a selected pen.

• Preview the expanded tag list.

• Filter available tags by a variety of different criteria.

Export Wizard: The Export Wizard button launches the Export Wizard that facilitates the exportation of data for the tags currently being plotted on the Historical Data Viewer page to an ODBC-compliant database, or to a comma-separated value (CSV) file.

Duration Selector: The duration selector drop-down list allows you to select from a variety of preset time periods or durations for the data being plotted on the graphs. These durations apply to all pens plotting data on both the analog and digital graphs. You may choose a preset duration ranging from 2 minutes to 5 years.

Select Start Date: The Select Start Date button launches a calendar that enables you to select a month and day on which you wish to see historical data for the pens currently plotting data on the graph.

Zoom In X-axis: The Zoom In X-axis button enables you to change the time scale on the x-axis to display a shorter duration on the graph(s).

Zoom Out X-axis: The Zoom Out X-axis button enables you to change the time scale on the x-axis to display a longer duration on the graph(s).

Zoom In Y-axis (Analogs Only): The Zoom In Y-axis (Analogs Only) button enables you to change the y-axis to display a lower minimum scale range on the analog graph.

Zoom Out Y-axis (Analogs Only): The Zoom Out Y-axis (Analogs Only) button enables you to change the y-axis to display a higher maximum scale range on the analog graph.

Shift Y-axis (Analogs Only): The Shift Y-axis (Analogs Only) button enables you to shift the position of a selected analog pen on the graph so that it is not obscured by (or does not obscure) the other plots on the graph.

Reset Y-axis (Analogs Only): The Reset Y-axis (Analogs Only) button enables you to reset shifted scale ranges and zoomed analog scale ranges to their original state.

Add Note: The Add Note button enables you to add a note to a notebook selected in the pen legend.

Time Scale

The time scale appears along the x-axis of the graph(s), and indicates the duration of data currently being plotted.

Date/Time Scroll Bar

The date/time scroll bar enables you to scroll backward and forward through the historical data being plotted on the graph.

Now that you are familiar with the layout of the Historical Data Viewer page, we shall explore its functionality in greater detail in the exercises that follow.