Imports System.Runtime.InteropServices
Imports System.Text
Imports System.Threading

#Region "RS232"
Public Class Rs232
'===================================================
	'												?002 Corrado Cavalli All rights reserved
	'
	'	Module				:	Rs232
	'	Description		:	Class for handling RS232 comunication with VB.Net
	'	Created				:	10/08/2001 - 8:45:25
	'	Author				:	Corrado Cavalli
	'
	'	Notes					:	
	'-----------------------------------------------------------------------------------------------
	'																		Revisions
	'	Rev.1	(28.02.2002)
	'	1.	Added ResetDev, SetBreak and ClearBreak to the EscapeCommFunction constants
	'	2.	Added the overloaded Open routine.
	'	3.	Added the modem status routines, properties and enum.
	'	4.	If a read times out, it now returns a EndOfStreamException (instead of a simple Exception).
	'
	'  Above modification suggested by:
	'	Richard J. Kucia
	'	Kucia Associates
	'	rjkucia@worldnet.att.net

	'	Rev.2	(01.02.2002)
	'	Added Async support
	'===================================================


	'// Class Members		
	Private mhRS As Int32 = -1	  '// Handle to Com Port									
	Private miPort As Integer = 1	  '//  Default is COM1	
	Private miTimeout As Int32 = 70	  '// Timeout in ms
	Private miBaudRate As Int32 = 9600
	Private meParity As DataParity = 0
	Private meStopBit As DataStopBit = 0
	Private miDataBit As Int32 = 8
	Private miBufferSize As Int32 = 512	  '// Buffers size default to 512 bytes
	Private mabtRxBuf As Byte()	  '//  Receive buffer	
	Private meMode As Mode	 '//  Class working mode	
	Private mbWaitOnRead As Boolean
	Private mbWaitOnWrite As Boolean
	Private mbWriteErr As Boolean
	Private muOverlapped As OVERLAPPED
	Private muOverlappedW As OVERLAPPED
	Private muOverlappedE As OVERLAPPED
	Private mabtTmpTxBuf As Byte()		'// Temporary buffer used by Async Tx
	Private moThreadTx As Thread
	Private moThreadRx As Thread
	Private miTmpBytes2Read As Int32
	Private meMask As EventMasks
	'----------------------------------------------------------------------------------------

#Region "Enums"
	'// Parity Data
	Public Enum DataParity
		Parity_None = 0
		Pariti_Odd
		Parity_Even
		Parity_Mark
	End Enum
	'// StopBit Data
	Public Enum DataStopBit
		StopBit_1 = 1
		StopBit_2
	End Enum
	Private Enum PurgeBuffers
		RXAbort = &H2
		RXClear = &H8
		TxAbort = &H1
		TxClear = &H4
	End Enum
	Private Enum Lines
		SetRts = 3
		ClearRts = 4
		SetDtr = 5
		ClearDtr = 6
		ResetDev = 7		 '	// Reset device if possible
		SetBreak = 8		 '	// Set the device break line.
		ClearBreak = 9		 '	// Clear the device break line.
	End Enum
	'// Modem Status
	<Flags()> Public Enum ModemStatusBits
		ClearToSendOn = &H10
		DataSetReadyOn = &H20
		RingIndicatorOn = &H40
		CarrierDetect = &H80
	End Enum
	'// Working mode
	Public Enum Mode
		NonOverlapped
		Overlapped
	End Enum
	'// Comm Masks
	<Flags()> Public Enum EventMasks
		RxChar = &H1
		RXFlag = &H2
		TxBufferEmpty = &H4
		ClearToSend = &H8
		DataSetReady = &H10
		ReceiveLine = &H20
		Break = &H40
		StatusError = &H80
		Ring = &H100
	End Enum
#End Region
#Region "Structures"
	<StructLayout(LayoutKind.Sequential, Pack:=1)> Private Structure DCB
		Private DCBlength As Int32
		Private BaudRate As Int32
		Private Bits1 As Int32
		Private wReserved As Int16
		Private XonLim As Int16
		Private XoffLim As Int16
		Private ByteSize As Byte
		Private Parity As Byte
		Private StopBits As Byte
		Private XonChar As Byte
		Private XoffChar As Byte
		Private ErrorChar As Byte
		Private EofChar As Byte
		Private EvtChar As Byte
		Private wReserved2 As Int16
	End Structure
	<StructLayout(LayoutKind.Sequential, Pack:=1)> Private Structure COMMTIMEOUTS
		Public ReadIntervalTimeout As Int32
		Public ReadTotalTimeoutMultiplier As Int32
		Public ReadTotalTimeoutConstant As Int32
		Public WriteTotalTimeoutMultiplier As Int32
		Public WriteTotalTimeoutConstant As Int32
	End Structure
	<StructLayout(LayoutKind.Sequential, Pack:=1)> Private Structure COMMCONFIG
		Private dwSize As Int32
		Private wVersion As Int16
		Private wReserved As Int16
		Private dcbx As DCB
		Private dwProviderSubType As Int32
		Private dwProviderOffset As Int32
		Private dwProviderSize As Int32
		Private wcProviderData As Byte
	End Structure
	<StructLayout(LayoutKind.Sequential, Pack:=1)> Public Structure OVERLAPPED
		Public Internal As Int32
		Public InternalHigh As Int32
		Public Offset As Int32
		Public OffsetHigh As Int32
		Public hEvent As Int32
	End Structure
#End Region
#Region "Constants"
	Private Const PURGE_RXABORT As Integer = &H2
	Private Const PURGE_RXCLEAR As Integer = &H8
	Private Const PURGE_TXABORT As Integer = &H1
	Private Const PURGE_TXCLEAR As Integer = &H4
	Private Const GENERIC_READ As Integer = &H80000000
	Private Const GENERIC_WRITE As Integer = &H40000000
	Private Const OPEN_EXISTING As Integer = 3
	Private Const INVALID_HANDLE_VALUE As Integer = -1
	Private Const IO_BUFFER_SIZE As Integer = 1024
	Private Const FILE_FLAG_OVERLAPPED As Int32 = &H40000000
	Private Const ERROR_IO_PENDING As Int32 = 997
	Private Const WAIT_OBJECT_0 As Int32 = 0
	Private Const ERROR_IO_INCOMPLETE As Int32 = 996
	Private Const WAIT_TIMEOUT As Int32 = &H102&
	Private Const INFINITE As Int32 = &HFFFFFFFF


#End Region

#Region "Win32API"
	'// Win32 API
	<DllImport("kernel32.dll")> Private Shared Function SetCommState(ByVal hCommDev As Int32, ByRef lpDCB As DCB) As Int32
	End Function
	<DllImport("kernel32.dll")> Private Shared Function GetCommState(ByVal hCommDev As Int32, ByRef lpDCB As DCB) As Int32
	End Function
	<DllImport("kernel32.dll", CharSet:=CharSet.Auto)> Private Shared Function BuildCommDCB(<MarshalAs(UnmanagedType.LPStr)> ByVal lpDef As String, ByRef lpDCB As DCB) As Int32
	End Function
	<DllImport("kernel32.dll")> Private Shared Function SetupComm(ByVal hFile As Int32, ByVal dwInQueue As Int32, ByVal dwOutQueue As Int32) As Int32
	End Function
	<DllImport("kernel32.dll")> Private Shared Function SetCommTimeouts(ByVal hFile As Int32, ByRef lpCommTimeouts As COMMTIMEOUTS) As Int32
	End Function
	<DllImport("kernel32.dll")> Private Shared Function GetCommTimeouts(ByVal hFile As Int32, ByRef lpCommTimeouts As COMMTIMEOUTS) As Int32
	End Function
	<DllImport("kernel32.dll")> Private Shared Function ClearCommError(ByVal hFile As Int32, ByVal lpErrors As Int32, ByVal l As Int32) As Int32
	End Function
	<DllImport("kernel32.dll")> Private Shared Function PurgeComm(ByVal hFile As Int32, ByVal dwFlags As Int32) As Int32
	End Function
	<DllImport("kernel32.dll")> Private Shared Function EscapeCommFunction(ByVal hFile As Integer, ByVal ifunc As Long) As Boolean
	End Function
	<DllImport("kernel32.dll")> Private Shared Function WaitCommEvent(ByVal hFile As Integer, ByRef Mask As EventMasks, ByRef lpOverlap As OVERLAPPED) As Int32
	End Function
	<DllImport("kernel32.dll")> Private Shared Function WriteFile(ByVal hFile As Integer, ByVal Buffer As Byte(), ByVal nNumberOfBytesToWrite As Integer, ByRef lpNumberOfBytesWritten As Integer, ByRef lpOverlapped As OVERLAPPED) As Integer
	End Function
	<DllImport("kernel32.dll")> Private Shared Function ReadFile(ByVal hFile As Integer, ByVal Buffer As Byte(), ByVal nNumberOfBytesToRead As Integer, ByRef lpNumberOfBytesRead As Integer, ByRef lpOverlapped As OVERLAPPED) As Integer
	End Function
	<DllImport("kernel32.dll")> Private Shared Function CreateFile(<MarshalAs(UnmanagedType.LPStr)> ByVal lpFileName As String, ByVal dwDesiredAccess As Integer, ByVal dwShareMode As Integer, ByVal lpSecurityAttributes As Integer, ByVal dwCreationDisposition As Integer, ByVal dwFlagsAndAttributes As Integer, ByVal hTemplateFile As Integer) As Integer
	End Function
	<DllImport("kernel32.dll")> Private Shared Function CloseHandle(ByVal hObject As Integer) As Integer
	End Function
	<DllImport("kernel32.dll")> Private Shared Function FormatMessage(ByVal dwFlags As Integer, ByVal lpSource As Integer, ByVal dwMessageId As Integer, ByVal dwLanguageId As Integer, <MarshalAs(UnmanagedType.LPStr)> ByVal lpBuffer As String, ByVal nSize As Integer, ByVal Arguments As Integer) As Integer
	End Function
	<DllImport("kernel32.dll")> Public Shared Function GetCommModemStatus(ByVal hFile As Int32, ByRef lpModemStatus As Int32) As Boolean
	End Function
	<DllImport("kernel32.dll")> Private Shared Function CreateEvent(ByVal lpEventAttributes As Int32, ByVal bManualReset As Int32, ByVal bInitialState As Int32, <MarshalAs(UnmanagedType.LPStr)> ByVal lpName As String) As Int32

	End Function
	<DllImport("kernel32.dll")> Private Shared Function GetLastError() As Int32


	End Function
	<DllImport("kernel32.dll")> Private Shared Function WaitForSingleObject(ByVal hHandle As Int32, ByVal dwMilliseconds As Int32) As Int32
	End Function
	<DllImport("kernel32.dll")> Private Shared Function GetOverlappedResult(ByVal hFile As Int32, ByRef lpOverlapped As OVERLAPPED, ByRef lpNumberOfBytesTransferred As Int32, ByVal bWait As Int32) As Int32

	End Function
	<DllImport("kernel32.dll")> Private Shared Function SetCommMask(ByVal hFile As Int32, ByVal lpEvtMask As Int32) As Int32
	End Function


	Private Declare Function FormatMessage Lib "kernel32" Alias _
	 "FormatMessageA" (ByVal dwFlags As Int32, ByVal lpSource As Int32, _
	 ByVal dwMessageId As Int32, ByVal dwLanguageId As Int32, _
	 ByVal lpBuffer As StringBuilder, ByVal nSize As Int32, ByVal Arguments As Int32) _
	 As Int32





#End Region
#Region "Events"
	Public Event DataReceived(ByVal Source As Rs232, ByVal DataBuffer() As Byte)
	Public Event TxCompleted(ByVal Source As Rs232)
	Public Event CommEvent(ByVal Source As Rs232, ByVal Mask As EventMasks)
#End Region

	Public Property Port() As Integer
		'===================================================
		'												?001 Corrado Cavalli All rights reserved
		'
		'		Description:		Comunication Port
		'		Created			:		21/09/2001 - 11:25:49
		'		Author				:		Corrado Cavalli
		'
		'												*Parameters Info*
		'
		'		Notes				:
		'===================================================
		Get
			Return miPort
		End Get
		Set(ByVal Value As Integer)
			miPort = Value
		End Set
	End Property
	Public Overridable Property Timeout() As Integer
		'===================================================
		'												?001 Corrado Cavalli All rights reserved
		'
		'		Description:		Comunication timeout in seconds
		'		Created			:		21/09/2001 - 11:26:50
		'		Author				:		Corrado Cavalli
		'
		'												*Parameters Info*
		'
		'		Notes				:
		'===================================================
		Get
			Return miTimeout
		End Get
		Set(ByVal Value As Integer)
			miTimeout = CInt(IIf(Value = 0, 500, Value))
			'// If Port is open updates it on the fly
			pSetTimeout()
		End Set
	End Property
	Public Property Parity() As DataParity
		'===================================================
		'												?001 Corrado Cavalli All rights reserved
		'
		'		Description:		Comunication parity
		'		Created			:		21/09/2001 - 11:27:15
		'		Author				:		Corrado Cavalli
		'
		'												*Parameters Info*
		'
		'		Notes				:
		'===================================================
		Get
			Return meParity
		End Get
		Set(ByVal Value As DataParity)
			meParity = Value
		End Set
	End Property
	Public Property StopBit() As DataStopBit
		'===================================================
		'												?001 Corrado Cavalli All rights reserved
		'
		'		Description:		Comunication StopBit
		'		Created			:		21/09/2001 - 11:27:37
		'		Author				:		Corrado Cavalli
		'
		'												*Parameters Info*
		'
		'		Notes				:
		'===================================================
		Get
			Return meStopBit
		End Get
		Set(ByVal Value As DataStopBit)
			meStopBit = Value
		End Set
	End Property
	Public Property BaudRate() As Integer
		'===================================================
		'												?001 Corrado Cavalli All rights reserved
		'
		'		Description:		Comunication BaudRate
		'		Created			:		21/09/2001 - 11:28:00
		'		Author				:		Corrado Cavalli
		'
		'												*Parameters Info*
		'
		'		Notes				:
		'===================================================
		Get
			Return miBaudRate
		End Get
		Set(ByVal Value As Integer)
			miBaudRate = Value
		End Set
	End Property
	Public Property DataBit() As Integer
		'===================================================
		'												?001 Corrado Cavalli All rights reserved
		'
		'		Description:		Comunication DataBit
		'		Created			:		21/09/2001 - 11:28:20
		'		Author				:		Corrado Cavalli
		'
		'												*Parameters Info*
		'
		'		Notes				:
		'===================================================
		Get