请教各位。下面是本人写的程序，为何得不到正确的结果？？？

请教各位。下面是本人写的程序，为何得不到正确的结果？？？

Private Sub Command1_Click()
  测试PLC是否接收到计算机发送的信息，并返回相应的响应。
Dim inputStr As String
Dim a As String，b As String，c As String，d As String
Dim e As String，f As String，g As String，h As String
Dim i As String，k As String，l As String，m As String
MSComm1.OutBufferCount = 0
MSComm1.InBufferCount = 0
DeviceDat = "00FFBW0Y000101"  或者是：DeviceDat = "00FFBW0X000102"，
                               DeviceDat = "00FFBW0T000101"等等。
MSComm1.Output = Chr(5) + DeviceDat + SumCheck(DeviceDat) + Chr(13)
TimeDelay 100  时间延迟函数
inputStr = MSComm1.Input
a = Mid(inputStr, 1, 1)：b = Mid(inputStr, 2, 1)
c = Mid(inputStr, 3, 1)：d = Mid(inputStr, 4, 1)
e = Mid(inputStr, 5, 1)：f = Mid(inputStr, 6, 1)
g = Mid(inputStr, 7, 1)：h = Mid(inputStr, 8, 1)
i = Mid(inputStr, 9, 1)：k = Mid(inputStr, 10, 1)
l = Mid(inputStr, 11, 1)：m = Mid(inputStr, 12, 1)
然后用一个文本框显示接收的字符串相应的字符码
Text1.Text = Text1.Text + "  " + CStr(Asc(a)) + "  " + CStr(Asc(b)) + "  " + CStr(Asc(c)) + "  " + CStr(Asc(d)) + "  " + CStr(Asc(e)) + "  " + CStr(Asc(f)) _
  + "  " + CStr(Asc(g)) + "  " + CStr(Asc(h)) + "  " + CStr(Asc(i)) ' + "  " + CStr(Asc(k))   '+ "  " + CStr(asc(l)) + "  " + CStr(asc(m))
但接收文本框的结果是：6  -27243  -27243  -27243  -27243  -27243  -27243  -27243  -27243
从实际运行中观察，当计算机向PLC发送MSComm1.Output 时，PLC的LED灯亮，接收
的字符码里也有6，说明PLC能接收到计算机发来的请求信息，并能响应，但为什么
其他返回的字符码却不正确（如用字符显示是同一个汉字。）


下面代码是如果PLC能正确返回PLC中的Y1点输出，就使相应的SHAPE1控件显红色
。但结果都是出现“返回错误”
'If inputStr = Chr(2) + "00FF1" + Chr(3) Then
'Shape1.FillColor = vbRed
'Else
'MsgBox "返回错误"
'End If


如复我信箱，那就理谢谢了(lj-000@163.net)。