纯代码实现浮点计算实际上对浮点算法的再实践。IEEE浮点表示法是Modbus RTU协议至今还在用的传送编码，更是WITS 1记录标准的基础。以往实现 MKI、CVI，MKL、CVL，MKS、CVS，MKD、CVD在高级语言里封装了现成的语句，现在PowerBasic和FreeBasic也可以将这些语句封闭到 DLL 中供其它语言调用。不过还是重编代码，对算法的演练更到位。

1. MKI/CVI

要点：对输入数据取整，判断正负，正数直接转换，负数加上65536后转换。输入数据分成高低各16位数据，范围在 &H0000 - &HFFFF之间。

Function MKI(ByVal iData As Integer) As String
    'MKI 16bits &HFFFF -32768 to 32767 8000-7fff
    Dim inData As Long
    Dim HiByte As Long, LoByte As Long
    
    inData = Fix(iData)
    If inData < 0 Then inData = inData + 65536
    
    LoByte = inData And &HFF
    HiByte = (inData \ 2 ^ 8) And &HFF
    
    MKI = Right$(("0" + Hex$(HiByte)), 2) + Right$(("0" + Hex$(LoByte)), 2)
End Function

2. MKL/CVl

MKL实现方法与MKI类似，它是32位的，因此输入的数据分成四个8位数据，在VB6中用Currency类型变量表示更便于计算。

Function MKL(ByVal lData As Long) As String
    Dim Phi4 As Currency, Phi3 As Currency, Phi2 As Currency, Phi1 As Currency
    Dim inData As Currency
    inData = Fix(lData)
    Phi4 = inData And &HFF
    Phi3 = (inData \ 2 ^ 8) And &HFF
    Phi2 = (inData \ 2 ^ 16) And &HFF
    Phi1 = (inData \ 2 ^ 24) And &HFF
    MKL = Right$(("0" + Hex$(Phi1)), 2) + Right$(("0" + Hex$(Phi2)), 2) + Right$(("0" + Hex$(Phi3)), 2) + Right$(("0" + Hex$(Phi4)), 2)
End Function

3. MKS/CVS

右移位求得整数部分二进制串，小数部分乘2取整形成小数二进制串，合并二进制串左移或右移小数点位置并舍去高位的 1 ，移位值加上127形成 exp 指数， 正负符号用0或1表示，结果是 s+exp+余下的小数。

    OffSetBits = 8
    AcuFactor = 32: OffSet = 127

    inData = sData
    
    inDataSingn = 0
    If inData < 0 Then inDataSingn = 1
    
    inData = Abs(inData)    'ignore singn
    ipart = Int(inData): fpart = (inData - ipart)
    
    If inData = 0 Then
        CaseID = 0
    Else
        'Convert ipart, the integer part, into byte array TempData1 MSB to LSB
        tipart = ipart: TempString = ""
        For I = 1 To AcuFactor
            TempString = Right$(Str$(tipart And &H1), 1) + TempString
            tipart = tipart \ 2 ^ 1
        Next I
        For I = 1 To AcuFactor
            If Mid$(TempString, I, 1) = "1" Then Exit For
            Mid$(TempString, I, 1) = " "
        Next I
            IntiStr = Trim(TempString)
    
        'Convert fpart, the fraction part, into byte array TempData2
        tfpart = fpart: TempString = ""
        For I = 1 To AcuFactor
            If tfpart = 0 Then Exit For
            tfpart = tfpart * 2
            tnpart = Int(tfpart): tfpart = tfpart - tnpart
            TempString = TempString + Right$(Str$(tnpart And &H1), 1)
        Next I
            FracStr = TempString
            
        If ipart > 0 Then CaseID = 1
        If ipart = 0 Then CaseID = 2
    End If

4. MKD/CVD

与MKS类同，只是exp由8位增加至11位，偏移值由127变为1023

    OffSetBits = 11
    AcuFactor = 64: OffSet = 1023

    inData = sData
    
    inDataSingn = 0
    If inData < 0 Then inDataSingn = 1
    
    inData = Abs(inData)    'ignore singn
    ipart = Int(inData): fpart = (inData - ipart)
    
    If inData = 0 Then
        CaseID = 0
    Else
        'Convert ipart, the integer part, into byte array TempData1 MSB to LSB
        tipart = ipart: TempString = ""
        For I = 1 To AcuFactor
            TempString = Right$(Str$(tipart And &H1), 1) + TempString
            tipart = tipart \ 2 ^ 1
        Next I
        For I = 1 To AcuFactor
            If Mid$(TempString, I, 1) = "1" Then Exit For
            Mid$(TempString, I, 1) = " "
        Next I
            IntiStr = Trim(TempString)
    
        'Convert fpart, the fraction part, into byte array TempData2
        tfpart = fpart: TempString = ""
        For I = 1 To AcuFactor
            If tfpart = 0 Then Exit For
            tfpart = tfpart * 2
            tnpart = Int(tfpart): tfpart = tfpart - tnpart
            TempString = TempString + Right$(Str$(tnpart And &H1), 1)
        Next I
            FracStr = TempString
            
        If ipart > 0 Then CaseID = 1
        If ipart = 0 Then CaseID = 2
    End If

最后的结果都要变成十六进制字符，以便传送和文件存储。

源代码下载：

https://download.csdn.net/download/weixin_45707491/88232263?spm=1001.2014.3001.5503