Getting Started with Trend Visualization

When you execute a trend, it is best to proceed with user guidance and the help of the trend wizard.

Procedure. Development of a visualization with trend

Create an empty standard project and program at least one variable into PLC_PRG.
PLC_PRG is declared and implemented
Add the Visualization object to the device tree below Application.
An empty visualization appears.
Open ToolBox → Special Controls.
Drag the Trend element to the visualization
The Trend Recording dialog with the Record Settings opens.
Select the task in which the trend recording will be executed.
Tip
In general the trend recording runs in the same task as the main program, i.e. PLC_PRG.
Therefore, select MainTask.
Add a trend variable with Add Variable and assign an IEC variable from PLC_PRG to the trend variable.
Click OK to close the Trend Configuration.
There is a recently created "Trend Recording" object below the Trend Recording Manager. The active visualization contains a Trend element that is selected.
Click Visualization → Insert elements for controlling trend elements.
The Trend Wizard dialog opens.
By default, all three controls are activated in the dialog. Click OK to exit the dialog.
The active visualization contains a trend with controls.
Set the application containing the trend objects to active.
Compile the application with F11.
Execute the Online → Login command.
Start the application with F5.
The target visualization appears. The visualization contains the trend diagram with the value curve of the variable. The controls enable user inputs.

Example 16. Visualization of the sinusoidal trend of an IEC variable

. The following objects are implemented in the project:

PLC_PRG
Visualization_Trend1
VisuWithTrend

The PLC_PRG program runs as part of the application on the controller.

PROGRAM PLC_PRG
VAR
    iVar : INT;
    rSin : REAL;
    rVar : REAL;
END_VAR
iVar := iVar + 1;
iVar := iVar MOD 33;
rVar := rVar + 0.1;
rSin := 30 * SIN(rVar);

Example 17. Visualization_Trend1

Visualization_Trend1 is the object that contains the configuration of the trend recording.

Example 18. VisuWithTrend

VisuWithTrend is the object that displays the trend.

The visualization contains four elements: one Trend and three controls. The properties of the trend are defined as follows.

Properties	Value
Trend recording	Visualization_Trend1
Show cursor
Show tooltip
Show frame
Date Range Picker	: Trend1DateRangeSelector
Time Picker	: Trend1TimeSelector
Legend	: Trend1Legend

VisuWithTrend at runtime