Getting notified when a signal changes

This example provides information on how to show an Object (for example: GraphicComponent) based on Signal Change. When the signal goes high the selected Object is made visible. Similar approach could be followed if Object has to be hidden.

The steps that will be performed in this topic are:

  1. Add the property and signals to the SmartComponent's XML file.

  2. Add the property and signal's descriptions to the XML resource file.

  3. Modify the code in the CodeBehind.cs file.

This example provides snippets of XML and C# that could be used within the smart component project. An active station is required for this example.

The topic considers that a SmartComponent project created from Visual Studio exists. Refer to topic Creating a SmartComponent on how to create it.

Note

The code in this topic can be tested using the default RobotStudio Smart Component template.

Solution

  1. Open the SmartComponent1.xml file. Declare one property and two signals, as shown below:

    <Properties>
    <DynamicProperty name="Object" valueType="ABB.Robotics.RobotStudio.ProjectObject"/>
</Properties>
<Signals>
    <IOSignal name="Execute" signalType="DigitalInput" autoReset="true"/>
    <IOSignal name="Executed" signalType="DigitalOutput" autoReset="true"/>
</Signals>

  2. Open the SmartComponent1.en.xml file. Provide descriptions for the component, its properties, and the signal.

    <SmartComponent name="SmartComponent1" description="Makes an object visible in the graphics">
    <DynamicProperty name="Object" description="The object to show"/>
    <IOSignal name="Execute" description="Set to high (1) to show the object"/>
    <IOSignal name="Executed" description="Goes high (1) when the operation is complete"/>
</SmartComponent>

  3. Open the CodeBehind.cs file and modify OnIOSignalValueChanged. When Signal changes, OnIOSignalValueChanged(SmartComponent, IOSignal) gets triggered. The Execute method is called to show the object in the graphics. Here are code snippets used to achieve the aforementioned task:

    • Get the signal object "Executed".
    IOSignal executed = component.IOSignals["Executed"];
    • Set the visible property to True and Pulse and signal.
    if (Execute(component))
{
   if (executed != null) 
      executed.Pulse();
}

Example

Open CodeBehind.cs file and edit OnIOSignalValueChanged to look like the following code.

public override void OnIOSignalValueChanged(SmartComponent component, IOSignal changedSignal)
{
    if (changedSignal.Name == "Execute" && (int)changedSignal.Value != 0)
    {
        IOSignal executed = component.IOSignals["Executed"];

        if (Execute(component))
        {
            if (executed != null) 
                executed.Pulse();
        }
    }
}

Add the method Execute to CodeBehind. The method gets the corresponding ProjectObject and sets the Visible property to true. In this example, reflection is used to get access to the properties.

protected bool Execute(SmartComponent component)
{
    ProjectObject obj = component.Properties["Object"].Value as ProjectObject;
    if (obj == null) return false;

    foreach (ProjectObject pObject in SmartComponent.GetCollectionObjects(obj))
    {
        System.Reflection.PropertyInfo pInfo = pObject.GetType().GetProperty("Visible");
        if (pInfo == null)
            return false;
        pInfo.SetValue(pObject, true, null);

    }
    return true;
}

Compiling the Code

Note

In order for the Library Compiler to find the code behind assembly asset it needs to be located in the same directory as the Library XML file. The template project contains the following Post-Build Event, that copies the assembly to the right place.

copy /y "$(TargetPath)" "$(ProjectDir)"

The LibraryCompiler.exe is executed as a Post-Build Event, which means it is executed after the C# project has been built, and the code behind asset has been created.

"%ProgramFiles(X86)%\ABB\RobotStudio {version}\bin\LibraryCompiler.exe" "$(ProjectDir)\SmartComponent1.xml" "$(ProjectDir)\"

Required Namespaces

ABB.Robotics.RobotStudio

ABB.Robotics.RobotStudio.Stations

See Also