急切求助！松下FP0的通讯问题

本人用松下FP0的PLC传输数据，但用VB却读不出数据来，十分着急！哪位高人看看我的程序，帮帮忙，小弟不胜感激！以下是我的代码
模块：
Option Explicit
----------------------------------------------------------------------------------------
Public Function CalBCC(ByVal CC$) As String
   Dim i As Integer
   Dim tempresult As Byte
   
   CC$ = LTrim(RTrim(CC$))
   tempresult = 0
   For i = 1 To Len(CC$)
    tempresult = tempresult Xor Asc(Mid$(CC$, i, 1))
    Next i
    CalBCC = Right$("0" + Hex$(tempresult), 2)

End Function
----------------------------------------------------------------------------------------------
Public Function Form_Command(ByVal CC$) As String
   Form_Command = LTrim(RTrim(CC$)) + CalBCC(CC$) + Chr$(&HD)

End Function
--------------------------------------------------------------------------------------------
Public Function Decimalstr(ByVal id_str) As Long
   Dim str As String
   Dim d As Integer
   str = Mid$(id_str, 3, 2) + Mid$(id_str, 1, 2)
   Dim i As Integer
   Dim comp As Long
   comp = 0
   For i = 1 To 4 Step 1
    If Mid$(str, i, 1) = "A" Then
    d = 10
   ElseIf Mid$(str, i, 1) = "B" Then
   d = 11
   ElseIf Mid$(str, i, 1) = "C" Then
   d = 12
   ElseIf Mid$(str, i, 1) = "D" Then
   d = 13
   ElseIf Mid$(str, i, 1) = "E" Then
   d = 14
   ElseIf Mid$(str, i, 1) = "F" Then
   d = 15
   Else
   d = Val(Mid$(str, i, 1))
   End If
   comp = comp + d * 16 ^ (4 - i)
   Next i
   Decimalstr = comp
End Function

窗体程序：
   Dim i As Integer
   Dim comm As String
   Dim comm1 As String
   Dim str As String
   Dim bcc As Byte
-----------------------------------------------------------
Private Sub Command1_Click() '打开端口
   MSComm2.PortOpen = True
End Sub
------------------------------------------------------------
Private Sub Command2_Click() '写数据
   If MSComm2.PortOpen = False Then
       MsgBox "端口没有打开！正在打开"
       MSComm2.PortOpen = True
   End If
   comm = "%01#WDD00101002001234"
   MSComm2.Output = Form_Command(comm)
End Sub
-----------------------------------------------------------
Private Sub Command3_Click()
   Unload Me
End Sub
--------------------------------------------------------------------
Private Sub Command4_Click() '读数据
   comm1 = "%01#RDD0010100200"
   MSComm2.Output = Form_Command(comm1)
   leng = MSComm2.InBufferCount
   str = MSComm2.Input
   Text1.Text = Decimalstr(str)
End Sub

谢谢，我对PLC也不熟，我学计算机的。
一共接入四个模拟量：V0、I0、V2、I2、V4、I4、V6、I6
再次感谢你！

急死了急死了，哥哥快一点！！！

松下PLC是16位的
不知道什么原因还是没有读出数据

上山下乡：
我已经把串口设置为9600.o.8.1
但是读出的数据不正确，都是4096