Option Explicit
 
Private Declare Function WideCharToMultiByte Lib "kernel32.dll" (ByVal CodePage _
  As Long, ByVal dwFlags As Long, lpWideCharStr As Any, ByVal cchWideChar As _
  Long, lpMultiByteStr As Any, ByVal cchMultiByte As Long, ByVal lpDefaultChar _
  As String, ByVal lpUsedDefaultChar As Long) As Long
 
Public Enum CRC16MODES
     CRC_CCITT = 1
     CRC_16 = 2
     CRC_XMODEM = 3
     CRC_ARC = 2
End Enum
 
Private CRCTbl(255) As Integer, Poly As Integer
Private bIndirect As Boolean, Init As Integer
Private Final As Integer, bReverseData As Boolean
Private bReverseCRC As Boolean, Mode As CRC16MODES
 
 
Private Sub Class_Initialize()
     CRCMode = CRC_CCITT
 
     ClacCRCTable Poly
End Sub
 
Public Property Get CRCMode() As CRC16MODES
     Mode = CRC16MODES
End Property
Public Property Let CRCMode(ByVal NewMode As CRC16MODES)
     Mode = NewMode
 
     Select Case NewMode
     Case CRC16MODES.CRC_CCITT
          Init = &HFFFF
          Poly = &H1021
          Final = &H0
          bReverseData = False
          bReverseCRC = False
          bIndirect = True
 
     Case CRC16MODES.CRC_XMODEM
          Init = &H0&
          Poly = &H8408
          Final = &H0
          bReverseData = True
          bReverseCRC = True
          bIndirect = True
 
     Case CRC16MODES.CRC_16
          Init = &H0&
          Poly = &H8005
          Final = &H0
          bReverseData = True
          bReverseCRC = True
          bIndirect = True
     End Select
End Property
 
Public Property Get Polynom() As Integer
     Polynom = Poly
End Property
Public Property Let Polynom(ByVal NewPoly As Integer)
     Poly = NewPoly
     ClacCRCTable Poly
End Property
 
Public Property Get IndirectInit() As Boolean
     IndirectInit = bIndirect
End Property
Public Property Let IndirectInit(ByVal bIndirectInit As Boolean)
     bIndirect = bIndirectInit
End Property
 
Public Property Get InitValue() As Integer
     InitValue = Init
End Property
Public Property Let InitValue(ByVal NewInitValue As Integer)
     Init = NewInitValue
End Property
 
Public Property Get FinalValue() As Integer
     FinalValue = Final
End Property
Public Property Let FinalValue(ByVal NewFinalValue As Integer)
     Final = NewFinalValue
End Property
 
Public Property Get ReverseData() As Boolean
     ReverseData = bReverseData
End Property
Public Property Let ReverseData(ByVal bReverseDataValue As Boolean)
     bReverseData = bReverseDataValue
End Property
 
Public Property Get ReverseCRC() As Boolean
     ReverseCRC = bReverseCRC
End Property
Public Property Let ReverseCRC(ByVal bReverseCRCValue As Boolean)
     bReverseCRC = bReverseCRCValue
End Property

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