CRC 有关问题高手帮看下

CRC 问题高手帮看下！
本人对CRC校验不是很了解！下面我把我的通讯协议发下，大家帮看看！我的这个程序怎么改！



读仪表当前累计

  STX地 址DTMCRCCRLF
  02 30 31 44 54 4d 32 38 0D 0A
其中：
STX — — 起始符， 02H
秤号 — — 地址2 位。如秤号为01 时， 即： 30H 31H
D — — 44H
T — — 54H
M — — 4DH
CRC — — 校验和，即其前面所有数值相加并转换为十进制， 然后取后两位并转为ASCII 码。（ 其中十位在前、个位在后;其他传输数据都是高位在前）
CR — — 回车 0DH
LF — — 换行 0AH


程序里这样用的：

 Call Lrc_Fun(SendStr, LRC_TMP, 5)  
  SendStr(6) = LRC_TMP(0)
  SendStr(7) = LRC_TMP(1)

定义的FUN:

Public Function Lrc_Fun(SendStr() As Byte, Lrc_data() As Byte, data_long As Byte)
  Dim Lrc_DD As Long
  Dim Lrc_byte As Byte
  Dim lRC_ll As Byte
  Dim Lrc_hl As Byte
  Lrc_DD = 0
  For i = 0 To data_long Step 2
  Lrc_DD = Lrc_DD + AsciiToDec(SendStr(i)) * 16 + AsciiToDec(SendStr(i + 1))
  Next i
  Lrc_byte = Lrc_DD Mod &H100
  Lrc_byte = Not Lrc_byte
  Lrc_byte = (Lrc_byte + 1) Mod &H100
  lRC_ll = Lrc_byte \ 16
  Lrc_hl = Lrc_byte Mod 16
  Lrc_data(0) = DecToAscii(lRC_ll)
  Lrc_data(1) = DecToAscii(Lrc_hl)
End Function


哪位帮我看看，问题出在哪里！！我试了！校验一直不对！！帮改改！非常感谢！

[解决办法]

VB code

Public Function Lrc_Fun(SendStr() As Byte, Lrc_data() As Byte, data_long As Byte)    Dim Lrc_DD As Long    Dim Lrc_byte As Byte    Dim lRC_ll As Byte    Dim Lrc_hl As Byte    Dim i As Long    Lrc_DD = 0    For i = 0 To data_long - 1 Step 2 '多算了一次'        Lrc_DD = Lrc_DD + AsciiToDec(SendStr(i)) * 16 + AsciiToDec(SendStr(i + 1))    Next i    '既然是按照十进制计算的……'    Lrc_byte = Lrc_DD Mod 100    lRC_ll = Lrc_byte \ 10    Lrc_hl = Lrc_byte Mod 10    Lrc_data(0) = DecToAscii(lRC_ll)    Lrc_data(1) = DecToAscii(Lrc_hl)End Function
[解决办法]
VB code
Private Sub Command1_Click()'初始化一个测试数据    Dim sendstr(10) As Byte    sendstr(0) = &H2    sendstr(1) = &H30    sendstr(2) = &H31    sendstr(3) = &H44    sendstr(4) = &H54    sendstr(5) = &H4D    sendstr(6) = 0    sendstr(7) = 0    sendstr(8) = &HD    sendstr(9) = &HA    '计算校验和    Call Lrc_Fun(sendstr, 5)End SubPublic Function Lrc_Fun(ByRef sendstr() As Byte, data_long As Byte)    Dim xx As Long, tmp As Long, tmp1 As Long    tmp = 0    tmp1 = 0        For xx = 0 To data_long        tmp = tmp + sendstr(xx)    Next    tmp = tmp Mod 100    tmp1 = tmp Mod 10    tmp = tmp \ 10        sendstr(data_long + 1) = 30 + tmp    sendstr(data_long + 2) = 30 + tmp1End Function