modibus脚本
'crc16校验代码
Public Function CRC16(ByVal SendStr As String) As String
Dim CRC16Lo As Byte, CRC16Hi As Byte 'CRC寄存器
Dim CL As Byte, CH As Byte '多项式码&HA001
Dim SaveHi As Byte, SaveLo As Byte
Dim i As Integer, j As Integer
Dim Flag As Integer
Dim StrLen As Integer
Dim TempStr As String
Dim Check() As Byte
If (SendStr = "") Then Exit Function
TempStr = ""
For i = 1 To Len(SendStr)
TempStr = Mid(Replace(SendStr, " ", ""), i, 1) '将字符串中的空格去掉
Next i
StrLen = Len(SendStr)
If (StrLen Mod 2) > 0 Then Exit Function '2个字母或数字为一个字节
StrLen = StrLen / 2 - 1
ReDim Check(StrLen)
For i = 0 To StrLen
Check(i) = Val("&H" + Mid(SendStr, i * 2 + 1, 2) + "&")
Next i
CRC16Lo = &HFF
CRC16Hi = &HFF
CL = &H1
CH = &HA0
For i = 0 To UBound(Check)
CRC16Lo = CRC16Lo Xor Check(i) '每一个数据与CRC寄存器进行异或
For Flag = 0 To 7
SaveHi = CRC16Hi
SaveLo = CRC16Lo
CRC16Hi = CRC16Hi \ 2 '高位右移一位
CRC16Lo = CRC16Lo \ 2 '低位右移一位
If ((SaveHi And &H1) = &H1) Then '如果高位字节最后一位为1
CRC16Lo = CRC16Lo Or &H80 '则低位字节右移后前面补1
End If '否则自动补0
If ((SaveLo And &H1) = &H1) Then '如果LSB为1，则与多项式码进行异或
CRC16Hi = CRC16Hi Xor CH
CRC16Lo = CRC16Lo Xor CL
End If
Next Flag
Next i
Dim ReturnData(1) As Byte
ReturnData(0) = CRC16Lo 'CRC低位
ReturnData(1) = CRC16Hi 'CRC高位
CRC16 = SendStr & Hex(ReturnData(0)) & Hex(ReturnData(1))
End Function
