Visu Value Change Handler Example

The sample project records variable value changes that were triggered by user input within the visualization.

Product description

All visualization elements that change the value of a variable by user input call the IValueChangedListener interface.
With this interface, the value changes can be recorded and then processed programmatically.

Sample project "VisuValueChangeHandler.project":

The function block FB_ValueChangedListener implements the interface IValueChangedListener.
In the PLC_PRG program, the function block is registered at ValueChangedListenerManager. When the value of a
visualization element changes, the ValueChanged method of the FB_ValueChangedListener function block is called.
In the sample project, all user inputs are written via the visualization to the log file of the device.
The corresponding visualization element can be selected using the input assistant.

System requirements and restrictions