the i/o operation has been aborted because of either a thread exit or an application request. serial

Private Sub SerialPort1_DataReceived(sender As Object, e As System.IO.Ports.SerialDataReceivedEventArgs) Handles SerialPort1.DataReceived

        Dim bytRxBuff(CurrentUserRqst.iRcvLength) As Byte


        Dim iRcvdLength As Integer = SerialPort1.Read(bytRxBuff, 0, CurrentUserRqst.iRcvLength)

        SerialPort1.DiscardInBuffer()
        SerialPort1.DiscardOutBuffer()


        'Debug.EvaluateStatement(iRcvdLength)

        'Cls_Error.WriteToErrorLog(iRcvdLength.ToString, iRcvdLength.ToString, "Error")

        ProcessFrame(bytRxBuff, iRcvdLength)

    End Sub

    Private Sub Send_Frame(ByVal bytFrame As Byte(), ByVal iRcvLength As Integer)
   

 
            If bytFrame(1) = &HC Then
                SerialPort1.ReceivedBytesThreshold = 7
            Else
                SerialPort1.ReceivedBytesThreshold = iRcvLength
            End If


         
            If SerialPort1.IsOpen Then
                SerialPort1.Write(bytFrame, 0, bytFrame.Length)
            End If


            System.Threading.Thread.Sleep(100)

      
    End Sub


    Private Sub LatestDownload_FormClosed(sender As Object, e As System.Windows.Forms.FormClosedEventArgs) Handles Me.FormClosed


        If SerialPort1.IsOpen Then
            'SerialPort1.DataReceived -= Receive
            SerialPort1.DiscardInBuffer()
            SerialPort1.DiscardOutBuffer()
            SerialPort1.Close()
        End If

    End Sub