/// <summary>
/// Acquires images from the automatic document feeder (ADF) of eSCL device.
/// </summary>
public void AcquireImagesFromDocumentFeederOfEsclDevice()
{
    // create eSCL device manager
    using (Vintasoft.EsclImageScanning.EsclDeviceManager deviceManager = new Vintasoft.EsclImageScanning.EsclDeviceManager())
    {
        // open eSCL device manager
        deviceManager.Open();

        // wait while the eSCL device manager searches for eSCL devices
        System.Threading.Thread.Sleep(deviceManager.DeviceSearchTimeout);
        // get count of eSCL devices
        int deviceCount = deviceManager.Devices.Count;
        if (deviceCount == 0)
        {
            System.Console.WriteLine("Devices are not found.");
            return;
        }

        // select the first eSCL device
        Vintasoft.EsclImageScanning.EsclDevice device = deviceManager.Devices[0];

        // open eSCL device
        device.Open();

        // if device does not have the automatic document feeder
        if (!device.HasFeeder)
        {
            System.Console.WriteLine("Device does not have the automatic document feeder.");
            return;
        }
        // enable the automatic document feeder
        device.IsFeederEnabled = true;
        // if the automatic document feeder can work in duplex mode
        if (device.HasDuplex)
        {
            // enable the duplex mode for the automatic document feeder
            device.IsDuplexEnabled = true;
        }

        Vintasoft.EsclImageScanning.EsclAcquiredImage acquiredImage;
        do
        {
            try
            {
                // acquire image from eSCL device
                acquiredImage = device.AcquireImageSync();
                // if image is received
                if (acquiredImage != null)
                {
                    System.Console.WriteLine("Image is acquired.");
                }
                // if image is not received
                else
                {
                    System.Console.WriteLine("Scan is completed.");
                    break;
                }
            }
            catch (System.Exception ex)
            {
                System.Console.WriteLine(string.Format("Scan is failed: {0}", ex.Message));
                break;
            }
        }
        // while image is acquired
        while (acquiredImage != null);

        // close eSCL device
        device.Close();

        // close eSCL device manager
        deviceManager.Close();
    }

    System.Console.ReadLine();
}

''' <summary>
''' Acquires images from the automatic document feeder (ADF) of eSCL device.
''' </summary>
Public Sub AcquireImagesFromDocumentFeederOfEsclDevice()
    ' create eSCL device manager
    Using deviceManager As New Vintasoft.EsclImageScanning.EsclDeviceManager()
        ' open eSCL device manager
        deviceManager.Open()

        ' wait while the eSCL device manager searches for eSCL devices
        System.Threading.Thread.Sleep(deviceManager.DeviceSearchTimeout)
        ' get count of eSCL devices
        Dim deviceCount As Integer = deviceManager.Devices.Count
        If deviceCount = 0 Then
            System.Console.WriteLine("Devices are not found.")
            Return
        End If

        ' select the first eSCL device
        Dim device As Vintasoft.EsclImageScanning.EsclDevice = deviceManager.Devices(0)

        ' open eSCL device
        device.Open()

        ' if device does Not have the automatic document feeder
        If device.HasFeeder = False Then
            System.Console.WriteLine("Device does not have the automatic document feeder.")
            Return
        End If
        ' enable the automatic document feeder
        device.IsFeederEnabled = True
        ' if the automatic document feeder can work in duplex mode
        If device.HasDuplex = True Then
            ' enable the duplex mode for the automatic document feeder
            device.IsDuplexEnabled = True
        End If

        Dim acquiredImage As Vintasoft.EsclImageScanning.EsclAcquiredImage
        Do
            Try
                ' acquire image from eSCL device
                acquiredImage = device.AcquireImageSync()
                ' if image is received
                If acquiredImage IsNot Nothing Then
                    System.Console.WriteLine("Image is acquired.")
                Else
                    ' if image is not received
                    System.Console.WriteLine("Scan is completed.")
                    Exit Try
                End If
            Catch ex As System.Exception
                System.Console.WriteLine(String.Format("Scan is failed: {0}", ex.Message))
                Exit Try
            End Try
            ' while image is acquired
        Loop While acquiredImage IsNot Nothing

        ' close eSCL device
        device.Close()

        ' close eSCL device manager
        deviceManager.Close()
    End Using

    System.Console.ReadLine()
End Sub