/// <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();

        System.DateTime startTime = System.DateTime.Now;
        // while eSCL devices are not found
        while (deviceManager.Devices.Count == 0 && System.DateTime.Now.Subtract(startTime).Microseconds < 5000)
        {
            System.Threading.Thread.Sleep(10);
        }
        // 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();


        // get names of supported scan input sources
        Vintasoft.EsclImageScanning.EsclScanInputSource[] supportedScanInputSources = device.GetSupportedScanInputSources();
        foreach (Vintasoft.EsclImageScanning.EsclScanInputSource supportedScanSource in supportedScanInputSources)
        {
            if (supportedScanSource == Vintasoft.EsclImageScanning.EsclScanInputSource.FeederWithoutDuplex ||
                supportedScanSource == Vintasoft.EsclImageScanning.EsclScanInputSource.FeederWithDuplex)
            {
                // specify that images must be acquired from automatic document feeder of eSCL device
                device.ScanInputSource = supportedScanSource;
                break;
            }
        }


        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()

        Dim startTime As System.DateTime = System.DateTime.Now
        ' while eSCL devices are not found
        While deviceManager.Devices.Count = 0 AndAlso System.DateTime.Now.Subtract(startTime).Microseconds < 5000
            System.Threading.Thread.Sleep(10)
        End While
        ' 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()


        ' get names of supported scan input sources
        Dim supportedScanInputSources As Vintasoft.EsclImageScanning.EsclScanInputSource() = device.GetSupportedScanInputSources()
        For Each supportedScanSource As Vintasoft.EsclImageScanning.EsclScanInputSource In supportedScanInputSources
            If supportedScanSource = Vintasoft.EsclImageScanning.EsclScanInputSource.FeederWithoutDuplex OrElse supportedScanSource = Vintasoft.EsclImageScanning.EsclScanInputSource.FeederWithDuplex Then
                ' specify that images must be acquired from automatic document feeder of eSCL device
                device.ScanInputSource = supportedScanSource
                Exit For
            End If
        Next


        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