''' <summary>
''' Adds the "custom" capability to the device capability collection.
''' </summary>
Public Shared Sub AddCustomDeviceCapability(device As Vintasoft.Twain.Device)
    ' open the device
    device.Open()

    Dim customCapId As System.UInt16 = 30000
    ' add the "custom" capability to the device capability collection
    device.Capabilities.Add(customCapId)

    ' get the "custom" capability
    Dim cap30000 As Vintasoft.Twain.DeviceCapability = device.Capabilities.Find(customCapId)
    Try
        ' set the current value of "custom" capability to True
        cap30000.SetValue(True)
    Catch ex As System.Exception
        System.Console.WriteLine(String.Format("Error: {0}", ex.Message))
    End Try
End Sub

/// <summary>
/// Adds the "custom" capability to the device capability collection.
/// </summary>
public static void AddCustomDeviceCapability(Vintasoft.Twain.Device device)
{
    // open the device
    device.Open();

    System.UInt16 customCapId = 30000;
    // add the "custom" capability to the device capability collection
    device.Capabilities.Add(customCapId);

    // get the "custom" capability
    Vintasoft.Twain.DeviceCapability cap30000 = device.Capabilities.Find(customCapId);
    try
    {
        // set the current value of "custom" capability to True
        cap30000.SetValue(true);
    }
    catch (System.Exception ex)
    {
        System.Console.WriteLine(string.Format("Error: {0}", ex.Message));
    }
}