Trend

The Trend page allows you to analyze historical data from plant variables. It is intended for operators who need to perform diagnostics, auditing, and in-depth analysis.

Quick overview

What it's for

• View historical measurements from monitored plant variables
• Perform diagnostics, auditing, and in-depth data analysis over time
• Use a reusable, configurable component that can also be integrated into Dashboards

Key concepts

• Device Tree (Plant/Device): Logical structure of the plant. Select one or more nodes (plants or individual devices).
• Variable Tree: Populated dynamically based on device selection; choose one or more variables to track.
• Interactive Chart: Time-based display of selected variables within the chosen interval.
  • X-axis: Time interval
  • Y-axis: Variable values, with multiple axes for different units of measurement
• Summary Table: Below the chart, one row per variable with metrics and display settings.

Prerequisites

• System access and permissions to view historical plant data
• Devices/variables mapped in the system (correctly configured telemetry)
• Time window of interest (e.g., last day, week, month)

Step-by-step guide

Select the context

1. In the Device Tree, select one or more plants/devices
2. Wait for the Variable Tree to populate

Choose variables

1. In the Variable Tree, select one or more variables
2. Verify that units of measurement are correct (multiple Y-axes if needed)

Set the time period

1. Open the Calendar and set start/end date and time
2. Apply the interval: the chart updates with historical data

Analyze the chart

1. Use zoom (drag on chart) and pan (Shift + drag) to navigate through time
2. Hover for tooltips showing date/time and exact values

Use the summary table

For each variable, the table shows:

• Name and unit of measurement
• Value at the selected instant (click on a point)
• Average and Sum over the interval
• Pen style: color, type (line, bar, step...), stroke (solid/dashed)
• Show/Hide toggle to display the variable in the chart

Export data

• Image: Export chart as PNG/SVG (depending on configuration)
• CSV: Export data within the selected interval

Chart interactions

Freezing the tooltip

When you double-click on the chart:

• The tooltip is frozen at that specific timestamp
• A vertical plot line appears as a marker
• Values at that exact point are displayed in the summary table
• You can drag the pinned tooltip to reposition it within the chart area

Handling invalid data

• Invalid samples are shown as gaps (empty spaces)
• The first invalid occurrence is visually indicated (markers/tooltips, if enabled)
• Statistics (average/sum) exclude invalid samples

Summary table columns

Additional features

• Widget resizing: Panels (trees/chart/table) are resizable to optimize space
• Interval presets: Today, yesterday, last 7/30 days (if configured)
• Save view: Store preferred selections and layout (if enabled)
• Series reordering: Drag and drop rows in the table to reorder the chart legend

Chart type options

Each series can be displayed using one of the following chart types:

Line style options

You can customize the appearance of each series with different line styles:

Additional options include ShortDot, ShortDashDot, LongDashDot, and more.

Series customization

Each series in the chart can be customized with:

Common errors and solutions

No variable selected

Problem: No series to display. Solution: Select at least one variable in the tree.

Invalid interval

Problem: Start date/time ≥ end date or outside available range. Solution: Correct the period in the calendar.

No data available

Problem: No historical data in the period or wrong device. Solution: Verify device, variable, and interval; try a wider range.

Incompatible units on the same axis

Problem: Series with different units on the same axis. Solution: Assign separate Y-axes or deselect conflicting series.

Frequently asked questions

How do I compare multiple variables?

Select multiple variables from the Variable Tree. Each will be displayed as a separate series on the chart.

Can I export the data?

Yes. Use the export buttons to download the chart as an image (PNG) or the data as CSV. The CSV export includes date, series name, value, and any associated messages.

Why do I see gaps in the chart?

Gaps indicate invalid or missing data samples during those time periods. Invalid points are marked with magenta square markers.

How do I zoom into a specific time range?

Drag on the chart to select the area you want to zoom into. Use the reset button to restore the original view.

How do I pan (scroll) through time?

Hold Shift and drag horizontally on the chart to scroll through time without changing the zoom level.

How do I freeze the tooltip at a specific point?

Double-click on the chart to freeze the tooltip at that timestamp. A vertical plot line will mark the position.

Can I drag the tooltip around?

Yes. When the tooltip is pinned (after double-clicking), you can drag it to reposition it within the chart boundaries.

Are the statistics updated when I zoom?

Yes. Min, Max, Average, and Sum values in the summary table are recalculated dynamically based on the visible time range.

What chart types are available?

You can choose from Line, Column, Scatter, Area, Step Left, and Step Right for each series.

How do I change the appearance of a series?

In the summary table, you can modify the color, line type (chart type), line style (solid, dashed, etc.), and line width for each series.