Chart Options for Trends

The chart object of a TrendWorX64 Viewer is where most of the properties of the viewer are configured. It sets visual properties such as the background color and axis titles, and also controls how data is retrieved.

The Chart tab contains general properties about the chart, such as the colors for the background, plot area, and grid. This tab is also where you can customize the context menu and configure commands on events.

This table describes some of the settings on this tab:

Setting name

Description

Alternate Plot Area

When a color is chosen, the plot area will alternate between this color and the plot area color. The alternations will happen between major x-axis grid lines. Learn more

Context Menu

Enables and configures the chart and pen context menus. Learn more

Commands on Events

Enables and configures commands that can be executed on events such as double-click or pen added. Learn more about commands

The Pens tab contains general settings about how pens are handled, such as how to treat uncertain or bad quality samples and default settings for newly added pens.

This table describes some of the settings on this tab:

Setting name

Description

Uncertain quality plot mode

Sets how uncertain quality samples are handled. The options are:

  • Leave gap - The line will end before the uncertain sample and resume at the next non-uncertain sample.
  • Plot - The uncertain sample will be plotted like good quality samples.
  • Span over - The samples before and after the uncertain samples will be connected as if the uncertain samples between them did not exist.

Bad quality plot mode

Same as uncertain quality plot mode, but for bad quality samples.

Maximum buffer size

The maximum amount of samples that can be buffered per pen in this chart. This limit prevents a pen with too many samples from using too much memory.

Show disabled pens

When checked, disabled pens are shown in the legend. When unchecked, they are hidden completely. (Disabled pens are never shown in the chart.)

Show invalid pens

When checked, pens with an invalid data source are shown in the legend and chart. When unchecked, they are hidden completely.

Runtime pen settings

The settings in this section set the properties for a pen added in runtime, such as via drag-and-drop or the add pen command. Learn more

Unique pens

If enabled, the viewer will not allow the same data source to be added as a pen more than once.

Color style

Defines the palette of colors used when pens are added in runtime.

The Data tab contains settings for how data is sampled, time values are displayed, and how the data and statistics export reports are configured.

This table describes some of the settings on this tab:

Setting name

Description

Sampling Method

This setting determines how the data is sampled and how often a sample is drawn on the viewer for each pen. The options are:

  • Interval - Samples will be collected at the given interval. This is recommended for viewers where the operator will not be zooming or changing the range. Expanding the range in runtime while using interval could result in an unexpectedly large number of samples and decreased performance.
  • Count - The sampling rate will be automatically determined from the range to ensure this number of samples per pen. For example, if your range is 1 hour and the count is 60, historical data will be sampled at a rate of 1 minute.
  • Auto - This is used with the automatic time alignment setting on the X Axis tab. It will automatically pick a sample rate to match the major tick marks configured in the time alignment. The maximum sampling interval is for this option is 1 hour.

For best performance, if you expect your operators to be zooming or changing the range, choose count. This will ensure consistent memory usage no matter the zoom level or range. A sampling method of interval can cause a decrease in performance if the viewer is zoomed out or the range is expanded significantly.

Different pen types use the sampling interval differently as described below:

  • Real-time pens - As a data collection rate
  • Historical aggregated pens - The historical sampling interval
  • Historical raw pens - Not used

General time settings > Custom format

When enabled, allows you to use an expression to customize your date and time format. Use the {{@@timestamp}} placeholder to represent the time being formatted.

The default expression is: x=tostring({{@@timestamp}})

This format applies to the legend and tooltip.

Use UTC time stamps

When checked, timestamps are displayed in UTC. When unchecked, timestamps are displayed in the client's local time zone.

Time zones alignment

Enables time zone alignment. To learn more about time zone alignment, click here.

The Range tab contains settings for the range and period of the chart, animation and history read rates, and settings related to freeze mode.

This table describes some of the settings on this tab:

Setting name

Description

Trend Range and Period

The period of time covered by the chart, ending with the current time.

Trend Period Toolbar

When checked, adds a series of buttons to the bottom of the chart that can be used to quickly change the trend period in runtime. Select the Configure button to customize the buttons on this toolbar. Learn more

Animation Speed

The speed at which the viewer is animated when not in freeze mode.

The faster the animation speed, the more resources will be required.

History Read Rate

The rate at which historical reads are made. If Optimize History Read rate is enabled, this becomes the minimum allowed history refresh rate.

This rate should not be faster than the sampling interval on the Data tab for aggregated historical data, or the data collection rate configured in the historian for raw historical data.

This does not affect real-time data sources.

Optimize History Read

When checked, the viewer will automatically choose an optimal history read rate, based on the sampling interval.

We recommend leaving this enabled for best performance.

Read range

When checked, the viewer will read the value in data source and change the chart range to match. This only applies when the viewer is in freeze mode.

Write range

When checked, the viewer will write its range to the data source point whenever the range is updated.

Data Source

The data source to use when reading or writing the viewer's range. You can enter a tag name manually or choose one of these options:

  • Browse - Use the tag browser to choose a tag, global alias, local variable, or expression.
  • Current range - The hard-coded value of the current range. This option is useful to see the syntax that will be used for the tag value, however leaving it configured with a hard-coded value like this is not recommended.
  • Default - Set it back to the default tag of: {{localsim::_timerange:String}}

The X Axis tab contains settings relating to the chart's x-axis. This is sometimes referred to as the "time axis".

This table describes some of the settings on this tab:

Setting name

Description

Automatic Time Alignment

When checked, the time labels on the x-axis will be automatically aligned with even or rounded timestamps. The exact timestamps will be determined from the viewer's range. For example, if your range is 5 hours, the times on the axis will be exact hours, such as 8:00:00 AM, 9:00:00 AM, etc.

To adjust the time alignment settings manually, disable Automatic Time Alignment and enable Time Alignment.

Style

The settings in this button determine the visual style for the x-axis, including its color, font, title, and the length in pixels of the major and minor tick marks. Learn more

Custom Format

When enabled, allows you to use an expression to customize your date and time format. Use the {{@@timestamp}} placeholder to represent the time being formatted.

The default expression is: x=tostring({{@@timestamp}})

Time Alignment

When checked, the time labels on the x-axis will be aligned with the given settings. For example, if time alignment is configured for 1 hour with a base alignment of 00:45:00 then the labels on the x-axis will show 45 minutes after each hour, such as 8:45:00 AM, 9:45:00 AM, etc..

Automatic Time Alignment must be unchecked to use this feature.

When Time Alignment and Automatic Time Alignment are both disabled, the time labels will be based on the left time of the viewer, and may be uneven, such as 8:05:32 AM.

The Y Axis tab contains settings relating to the chart's y-axis. This is sometimes referred to as the "value axis".

This table describes some of the settings on this tab:

Setting name

Description

Shared Value Axis

When enabled, all pens in the chart can share y-axes. These shared axes can be configured using the Configure button. Learn more
When disabled, each pen will have its own y-axis.

Pen axis range selection

When enabled, the user can change what range is displayed next to the chart in runtime by selecting a pen in the legend.

This option is only available if shared value axis is disabled.

Axis sorting

Sets how the y-axes are resorted when a pen is selected, based on these options:

  • Shift - The relative order of the axes is preserved, but they are rotated or shifted so the selected pen is closest to the chart.
  • Stack - The axis of the selected pen is taken out of the existing order and moved closest to the chart.

This option is only available if shared value axis is disabled.

Visible ranges

When shared axes are not in use, this sets the number of visible y-axes. If you have more pens than this value, the y-axes for the extra pens will be hidden.

The Cursors tab contains settings for cursors in freeze mode and real-time mode.

This table describes some of the settings on this tab:

Setting name

Description

Enable cursor user input

When enabled, allows the user to move the cursor with the mouse, touch, or keyboard.

Use mouse click or tap to move cursors

When enabled, the user can move the cursor to a new position by clicking or tapping the chart in that position.

Move cursors by mouse hover

When enabled, the cursor will follow the mouse cursor when it is moved over the chart.

This setting cannot be used when the second cursor is enabled.

Enabling this setting disables the ability to zoom using the mouse.

Read cursor position

When enabled, cursors will move to the position indicated by their data source when the data source is updated.

Write cursor position

When enabled, the position of the cursors will be written to their data source when the cursor is moved.

Sample Selection

Determines which sample is selected by the cursor. It can have one of these values:

  • Previous sample - The closest sample to the cursor in the past.
  • Closest sample - The closest sample to the cursor in either direction.
  • Next sample - The closest sample to the cursor in the future.
  • Interpolate - Interpolate the value and time from the samples on both sides of the cursor.

First Cursor > Data Source

The data source used for reading and writing for the first cursor.

This field is only enabled if either read cursor position or write cursor position are enabled.

Second Cursor > Data Source

The data source used for reading and writing for the second cursor.

This field is only enabled if second cursor and either read cursor position or write cursor position are enabled.

Read cursor tooltip visibility

When enabled, the cursor tooltip's visibility is read from the data source when the data source is updated.

Write cursor tooltip visibility

When enabled, the cursor tooltip's visibility is written to the data source when the visibility changes.

Show cursor tooltips > Data Source

The data source used for reading and writing the tooltip visibility.

This field is only enabled if either read cursor tooltip visibility or write cursor tooltip visibility are enabled.

The Summary tab contains settings for the chart's summary view.

This table describes some of the settings on this tab:

Setting name

Description

Size

The height of the summary view in pixels.

Cursor Fill

The color to use when shading the area between the cursors in summary view.

In GraphWorX64 runtime, this color is used to shade the area outside the cursors.

Time Aligned Cursors

If time alignment is enabled on the X Axis tab, enabling this will ensure moving the summary cursors results in a time-aligned window.

Snap Mode

When in snap mode, summary view behaves as follows:

  • Cursors cannot be freely moved but instead snap to the nearest axis tick mark.
  • The time range cannot be changed - the cursors cannot be moved further or closer to each other.
  • The selected area can be moved with a single mouse click.

Summary Period

The period covered by the summary view.

Custom Format

When enabled, allows you to use an expression to customize your date and time format. Use the {{@@timestamp}} placeholder to represent the time being formatted.

The default expression is: x=tostring({{@@timestamp}})

The Legend tab contains settings for the chart's legend.

This table describes some of the settings on this tab:

Setting name

Description

Context Menu

When enabled, provides a context menu for the legend. Use the configure button to customize the menu. Learn more

Colored Details

When enabled, colors the text of each legend row to match the pen color. When disabled, the text uses the row text color.

Available Columns

Columns that are available to be added to the legend. Use the > button to add them.

Selected Columns

Columns that will be displayed in the legend. Use the < button to remove them and the Up and Down buttons to rearrange them.

See TrendWorX64 Viewer Chart Advanced Tab