小弟我是用VB6.0写的,连线的PLC是三菱Q系列的
用RS232连线.
MSComm设定是19200,E,7,2 交握协定是设定2-com RTSXonXoff
我最主要的需求就是将数值传送给寄存器D
以下是我的VB编程以及模组
Private Sub Command1_Click()
Call Word_Write(MSComm1, FindAddrWord("D151"), Text1.Text)
End Sub
Private Sub Command2_Click()
Call Word_Write(MSComm1, FindAddrWord("D231"), Text2.Text)
End Sub
Private Sub Command3_Click()
Call Word_Write(MSComm1, FindAddrWord("D151"), Text1.Text)
Call Word_Write(MSComm1, FindAddrWord("D231"), Text2.Text)
Call Word_Write(MSComm1, FindAddrWord("D141"), Text3.Text)
End Sub
Private Sub Command4_Click()
Text1.Text = ""
Text2.Text = ""
Text3.Text = ""
Text1.SetFocus
End Sub
Private Sub Command5_Click()
End
End Sub
Private Sub Command6_Click()
Call Word_Write(MSComm1, FindAddrWord("D141"), Text3.Text)
End Sub
Private Sub Timer1_Timer()
Text4.Text = Word_Read(MSComm1, FindAddrWord("D141"))
End Sub
模组1:
Public Function FindAddrWord(sName As String) As String
 Dim strTagType As String
 Dim strTmp As String
 strTagType = Left$(sName, 1)
 strTmp = Right$(sName, Len(sName) - 1)
 Select Case UCase(strTagType)
   Case "C"
     FindAddrWord = "0" + Hex(Val(strTmp) * 2 + 2560)
   Case "T"
     FindAddrWord = "0" + Hex(Val(strTmp) * 2 + 2048)
   Case "D"
     FindAddrWord = Hex(Val(strTmp) * 2 + 4096)
 End Select
 Exit Function
End Function
模组2:
Public Function Word_Read(Comm As MSComm, sAddr As String) As String
 Dim STX As String
 Dim Cmd As String
 Dim Addr As String
 Dim ByteNum As String
 Dim ETX As String
 Dim CheckString As String
 Dim CheckCode As String
 Dim CmdCode As String
 Dim Sum As Integer
 Dim n As Integer
 Dim tmp As String
 STX = Chr(2)
 Cmd = "0"
 Addr = sAddr
 ByteNum = "02"
 ETX = Chr(3)
 CheckString = Cmd + Addr + ByteNum + ETX
 For n = 1 To Len(CheckString)
   Sum = Sum + Asc(Mid$(CheckString, n, 1))
 Next n
 CheckCode = Right$(Hex(Sum), 2)
 
 CmdCode = STX + Cmd + Addr + ByteNum + ETX + CheckCode
 Comm.PortOpen = True
 Comm.Output = CmdCode
 Do While Len(tmp) < 8
    tmp = tmp + Comm.Input
    n = n + 1
    If n >= 3000 Then
       Comm.PortOpen = False
       Exit Function
    End If
 Loop
 tmp = Mid$(tmp, 2, 4)
 Word_Read = Hex2Dec(Right$(tmp, 2) + Left$(tmp, 2))
 Comm.PortOpen = False
End Function
Public Function Word_Write(Comm As MSComm, sAddr As String, sWriteData As Integer) As String
 Dim STX As String
 Dim Cmd As String
 Dim Addr As String
 Dim ByteNum As String
 Dim WriteData As String
 Dim ETX As String
 Dim CheckString As String
 Dim CheckCode As String
 Dim CmdCode As String
 Dim Sum As Integer
 Dim n As Integer
 Dim tmp As String
 STX = Chr(2)
 Cmd = "1"
 Addr = sAddr
 ByteNum = "02"
 WriteData = Hex(sWriteData)
 If Len(WriteData) < 4 Then
    Do While Len(WriteData) < 4
       WriteData = "0" + WriteData
    Loop
 Else
   WriteData = Right$(WriteData, 4)
 End If
 WriteData = Right$(WriteData, 2) + Left$(WriteData, 2)
 ETX = Chr(3)
 CheckString = Cmd + Addr + ByteNum + WriteData + ETX
 For n = 1 To Len(CheckString)
   Sum = Sum + Asc(Mid$(CheckString, n, 1))
 Next n
 CheckCode = Right$(Hex(Sum), 2)
 CmdCode = STX + Cmd + Addr + ByteNum + WriteData + ETX + CheckCode
 Comm.PortOpen = True
 Comm.Output = CmdCode
 Do While Len(tmp) < 1
    tmp = tmp + Comm.Input
    n = n + 1
    If n >= 3000 Then
       Comm.PortOpen = False
       Exit Function
    End If
 Loop
 Word_Write = Hex(Asc(tmp))
 Comm.PortOpen = False
End Function
模组3:
Public Function Hex2Dec(strHex As String) As Long
 Dim strTmp As String
 Dim longTmp As Long
 Dim longDec As Long
 Dim intLen As Integer
 Dim n1 As Integer
 intLen = Len(strHex)
 For n1 = 1 To intLen
   strTmp = Mid(strHex, n1, 1)
   
   Select Case Asc(strTmp)
   Case 48 To 57
     longTmp = Val(strTmp)
   Case 65 To 70
     longTmp = Asc(strTmp) - 55
   Case Else
     Hex2Dec = 0
     Exit Function
   End Select
 
   longDec = longDec + longTmp * 16 ^ (intLen - n1)
 Next n1
 Hex2Dec = longDec
End Function