Function readData(ByRef objStream As NetworkStream, ByRef objTcpClient As TcpClient) As String
        Dim objStreamReader As New System.IO.StreamReader(objStream) 'streamreader per la lettura dei caratteri da un flusso di byte
        Dim sBuffer As String = Nothing

        objStream.ReadTimeout = 2000

        Try
            sBuffer = objStreamReader.ReadToEnd
            'write_Log("[iIntRead]: " + iIntRead.ToString + vbNewLine)
        Catch ex As IOException 'cattura dell'eccezione di tipo IOException
            'write_Log("[Errore] : timeout scaduto" + vbNewLine)
        End Try

        objStreamReader.Dispose() ' rilascio delle risorse
        objStreamReader.Close() ' chiusura dello streamreader
        Return sBuffer
    End Function