PLC与PC机通讯的VB源程序

PLC与PC机通讯的VB源程序大体如下：我采用的是FX232BD通讯模块，协议就是FX通讯协议。

强制PLC为RUN

Private Sub command1_Click()
   Dim dat As String
   commli.OutBufferCount = 0
    commli.InBufferCount = 0
           dat = "01FFRR0"
    commli.Output = Chr$(5) + dat + SumChk(dat)
   
End Sub

强制PLC为STOP

Private Sub command2_Click()
   Dim dat As String
   commli.OutBufferCount = 0
   commli.InBufferCount = 0
   dat = "01FFRS0"
   commli.Output = Chr$(5) + dat + SumChk(dat)
   
End Sub

强制Y0为1

Private Sub command3_Click()
   Dim dat As String
   commli.OutBufferCount = 0
   commli.InBufferCount = 0
   commli.Output = “01FFBW0Y001011”
   
End Sub

强制Y0为0

Private Sub command3_Click()
   Dim dat As String
   commli.OutBufferCount = 0
   commli.InBufferCount = 0
   commli.Output = “01FFBW0Y001010”
   
End Sub

设置电脑通信参数

Private Sub Commlis()
  
    If commli.PortOpen = True Then
        commli.PortOpen = False
    End If
    If Not commli.PortOpen Then
        commli.CommPort = 1 ''通信口
        commli.Settings = "9600,N,8,1"
        commli.Handshaking = 0
        commli.InputLen = 0
        commli.OutBufferCount = 0
        commli.InBufferCount = 0
        commli.PortOpen = True
    End If
    Exit Sub

   
End Sub
Private Function SumChk(Dats$) As String
    Dim i&
    Dim CHK&
    For i = 1 To Len(Dats)
        CHK = CHK + Asc(Mid(Dats, i, 1))
    Next i
 
    SumChk = Right(Hex$(CHK), 2)
End Function