Trend Chart Functions
This topic describes the tasks you can perform on a trend chart.
The following image shows an example of a trend chart.
Task | Procedure |
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Access the properties used in a trend chart. | The properties used in a trend chart appear in the Legend section. |
Show/Hide the plotted data | To display this option, select a property from the trend chart legend. Use to show or hide the data on the chart. |
Remove a property from the trend chart. | To delete plotted data from the trend chart, select the respective property from the legend, then select . |
Increase the area of a trend chart. |
|
Pause the data flow of a trend chart. | This option is available only for the live mode.
|
View the delta value between two data points. | The delta values for the trend is displayed in the
Legend section. On the toolbar, select , and select the two data points whose delta value you want to view. |
View the real-time value and units display in Live Mode | In Live mode, the legend displays the current value and Engineering Units (EGU). As updates are received from the data subscription, these values are dynamically updated in the legend. This allows you to see real-time updates of the current value and its corresponding units as they change over time. |
Display units on the Y-axis | If a source tag has engineering units, then the unit information
appears on the chart's y-axis, legend, and tooltip. Units do not appear on a single y-axis. If you opted for a single y-axis configuration, the units appear only on the chart's legend and tooltip. |
Drill down a trend chart. | On the toolbar, select to drill down or zoom into a trend chart for more granular information.
To zoom out, select .
If you want to zoom in or zoom out a single axis, select the axis in the drop-down list box next to . If you want to enlarge an area on the chart, select , and then select the area on the chart. Data is re-fetched only in historical mode when zoomed in/out (changes chart start time/duration) of a chart. For example, consider trending 500 samples from 1-2pm, then zoom in to 1:00 - 1:10pm to request 500 samples data for that 10 minute span. |
Pan across a trend chart. | You must zoom in/out of a chart to be able to pan across a trend chart.
The pan icon is enabled when you perform the zoom operation. The pan icon is visible only in the Live mode.
In Historical mode:
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Mark a trend chart view as favorite. It is an easy way to view the trend chart for commonly used configuration settings. | On the toolbar, select , enter a name for the
view, and then select Add. Important: Special characters To load a
favorite view, select the view from the drop-down list box next to .
? / \ # ; % are not
supported. Do not include them in your favorite name.You can also access the list of saved favorites while creating application pages in Operation Hub. Under Trend Card widget properties, select a favorite chart view from Select Favorite drop-down list. The selected view loads by default when you launch the trend chart at runtime. |
View the statistics of tags plotted on a trend chart. | On the toolbar, select to show/hide the statistical data for Historian
tags used in the trend chart. The statistics appear below the chart. In historical mode, tag statistics are re-fetched on zooming in/out (changes chart start time/duration) of a chart. |
Trend Card | This is the default chart type. There are three chart types:
You can access other chart types from the trend chart toolbar. |
Stacked Y-axis | On the toolbar, select Stacked Y-Axis to stack
multiple charts. For example, if you choose to trend four tags, the chart
appears with a common x-axis and a stacked y-axis. With a stacked y-axis,
you can:
Note:
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Tabular View | On the toolbar, select Tabular View to display
data in a table format.
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Export the trend chart data. | The trend chart data is exported and saved as a CSV file. On the
toolbar, select ,
then select to export
data. |
Print a trend chart. | On the toolbar, select , then select . You have the option to provide a title that
appears above the trend chart. |
Reset the trend chart options. | On the toolbar, select , then select . Any changes you have made to the duration, start time, axis preferences, and properties are reverted. |
Scroll through the historical data. | Select and to move back and forth
in the chart, and access historical data. Scrolling back and forth changes
the start time for the chart. For example, if you are currently viewing trends during 1-2pm, you can scroll back in time to view 12:45-1:45pm, then return to current view. |
Use tag groups for flexible trending. | You can dynamically choose which tags to include in the trend chart
without having to rely on pre-set favorites. Imagine you have an application with a chart that shows trends over time. The chart can display information about historical data, data from iFIX, CIMPLICITY, or a mix of sources. Instead of manually selecting each specific set of data every time, you can use buttons in the app to quickly switch between different sets of data. |
Trend Chart Guidelines
- When you add a trend chart to a page using the page designer, use separate containers for the breadcrumb and the chart. For the trend chart, set the height to 100%.
- When accessing a trend chart on a mobile device:
- Use a device with medium to high resolution.
- Use the device in landscape mode.
- To print a trend chart using an Android device, use the screen capture feature rather than selecting .
- Configure the trend chart using a desktop rather than an Android device. This is because when you attempt to search for an asset or a Historian tag on an Android device, the in-built keyboard of the device appears, which may not allow you to enter the search criteria.
- When you view the delta between two data points, the value may not be clearly readable on a mobile device with low to medium resolution. Therefore, we recommend that you view the delta value on a desktop or a mobile device with high resolution.
- When you view statistical data, the trend chart area may be limited. To avoid this issue, plot up to two properties on the trend chart.
- To pan across the trend chart or drill down the trend chart on an iPad, use the Zoom feature of the iPad rather than selecting , , or , respectively.