最近在研究VB跟欧姆龙CP1H的通信.了解到可以用串口进行HOSTLINK通信,还可以用以太网进行FANS通信.CP1H没有网口所以不可以用FANS通信吗?串口通信情况下,PLC处于运行时写入不了数据,只有当PLC是监控状态时才能写入.这怎么能达到随时写入的目的呢?

将PLC的运行模式改为监控模式就行了!

研究了几天,终于明白,FINS协议也可以通过串口和PLC通信上

      FINS通讯命令，0401可以让PLC进入运行/监控模式，0402可以让PLC进入停止模式。
      实测用0402让PLC停止后还可以用0101和0102对DM区进行读写。
      另：串口的hostlink模式FINS命令只能上位机控制PLC，PLC无法主动发数据给上位机。通过看w227文件，发现FINS帧格式自由度比较高，理论上来讲可以通过修改帧里面的命令符进行PLC通过串口对上位机发送数据，就好像用以太网发送一样。但是欧姆龙PLC说明书里面并没这方面的介绍。目前来说，PLC通过串口主动发数据给上位机发送数据要用无协议通讯。但是无协议通讯的话上位机无法控制PLC的开关状态。小弟刚学欧姆龙通讯，好多东西还不懂，望论坛各位前辈不吝赐教。

不用PLC发,上位机不断的读取就可以了.FINS协议是最好的.在运行时可以对PLC进行读,写操作.HOSTLINK在PLC运行时可以读,但要写入必须把PLC改成监控模式,太烦.

可以用FINS tcp/ip

Use for Fins TCP/IP.

Public Class OmronFins
    Dim WithEvents OmronPLC As New System.IO.Ports.SerialPort
    Dim WithEvents T1 As New Timer
    Dim MLog As New MyFB.RunErrLog


    ''' <summary>
    ''' PLC返回字符
    ''' </summary>
    ''' <remarks></remarks>
    Dim PLCRtString As String

    ''' <summary>
    ''' =True 等待RS返回信息
    ''' </summary>
    ''' <remarks></remarks>
    Dim PLCBusyBit As Boolean = False
    Dim PLCCommd As Integer = 0

    Dim RtValue(19) As String
    Dim RtErrValue(19) As String


    Sub RS232PortSet(ByVal PortNum As Integer)

        Try
            With OmronPLC
                .BaudRate = 38400
                .StopBits = 2
                .DataBits = 7
                .Parity = IO.Ports.Parity.Even
                .PortName = "COM" & PortNum
                .ReceivedBytesThreshold = 1
            End With

            If OmronPLC.IsOpen = False Then
                OmronPLC.Open()
            End If
        Catch ex As Exception
            MLog.LogErrWrite(ex.ToString)
        End Try



    End Sub

    Sub RS232PortClose()
        If OmronPLC.IsOpen = True Then
            OmronPLC.Close()
        End If
    End Sub

    Sub RS232SendMsg(ByVal SendString As String)
        Dim LenNum As Integer
        LenNum = SendString.Length
        If OmronPLC.IsOpen = True Then
            OmronPLC.Write(SendString)
        Else
            PLCBusyBit = False
        End If

    End Sub



    ''' <summary>
    ''' 20150525
    ''' Fins通讯计算校验码
    ''' </summary>
    ''' <param name="Value">传入需要校验内容</param>
    ''' <returns>返回Fins校验值</returns>
    ''' <remarks></remarks>
    Public Function FinsFcsCheck(ByVal Value As String) As String

        Dim CheckValue As Integer
        Dim CheckHex As String

        For i As Integer = 1 To Value.Length
            CheckValue = Asc(Mid(Value, i, 1)) Xor CheckValue
        Next
        CheckHex = Hex(CheckValue)
        If CheckHex.Length < 2 Then
            CheckHex = "0" & CheckHex
        End If

    
        Return CheckHex


    End Function
    ''' <summary>
    ''' 20150526
    ''' 写单个PLC值函数
    '''
    ''' </summary>
    ''' <param name="AddName"></param>
    ''' <param name="Value"></param>
    ''' <returns></returns>
    ''' <remarks></remarks>
    Public Function SetValue(ByVal AddName As String, ByVal AddNum As Integer, ByVal Value As Integer) As Integer

        Dim AddNumHexLen As Integer '地址16进制长度
        Dim HexAddNum As String     '地址值转到16进制
        Dim HCode As String = "@00FA000000000" '通讯表头
        Dim CommandCode As String = "0102"    '通讯命令代码
        Dim MemoryAreaCode As String          'PLC内存功能码
        Dim BitNum As String = "00"           '位写入需要写数值 0-15；字写如=0
        Dim WriteNum As String = "0001"        '写PLC地址个数；单个写入=0001
        Dim HexValue As String                '写入数值转换为16进制
        Dim FCSString As String               '需要校验的字符串
        Dim FCSValue As String                '命令校验码
        Dim EndCode As String = "*" & vbCr    '结束码
        Dim SenCode As String                 '发送到PLC字符串
        '*************************************************************************
        '修改版本20150526 新建
        '写入数值到D
        '通讯发送命令
        'HCode & CommandCode & MemoryAreaCode  & HEXADDNum & BitNum & WriteNum & Value & FCS & EndCode
        '*************************************************************************


        Try
            If PLCBusyBit = False And OmronPLC.IsOpen Then
                PLCCommd = 1
                PLCBusyBit = True
                '选择写入PLC地址类型
                Select Case AddName
                    Case "D"
                        MemoryAreaCode = "82"
                    Case Else
                        Return 1000
                        Exit Function
                End Select


                '写入地址转换为HEX，计算长度是否=4；长度不够补满
                HexAddNum = Hex(AddNum)
                AddNumHexLen = HexAddNum.Length
                Select Case AddNumHexLen
                    Case 1
                        HexAddNum = "000" & HexAddNum
                    Case 2
                        HexAddNum = "00" & HexAddNum
                    Case 3
                        HexAddNum = "0" & HexAddNum
                    Case 4
                        HexAddNum = HexAddNum
                    Case Else
                        Return 1001
                        Exit Function
                End Select

                '写入数值转换位16进制，计算长度=4；长度不够布满
                HexValue = Hex(Value)
                Select Case HexValue.Length
                    Case 1
                        HexValue = "000" & HexValue
                    Case 2
                        HexValue = "00" & HexValue
                    Case 3
                        HexValue = "0" & HexValue
                    Case 4
                        HexValue = HexValue
                    Case Else
                        Return 1002
                        Exit Function
                End Select

                FCSString = HCode & CommandCode & MemoryAreaCode & HexAddNum & BitNum & WriteNum & HexValue

                FCSValue = FinsFcsCheck(FCSString)

                SenCode = FCSString & FCSValue & EndCode
                RS232SendMsg(SenCode)
                ' Threading.Thread.Sleep(10)
                '***************************************************
                '20150608 返回结果处理

                Dim StartTick As Integer
                StartTick = Environment.TickCount
                Do
                    If (Environment.TickCount - StartTick) > 1500 Then
                        '超时报警
                        PLCBusyBit = False
                        Return 9001
                        Exit Do
                    End If

                    If PLCBusyBit = False Then

                        Exit Do
                    End If
                    Application.DoEvents()
                Loop

                If RtErrValue(0) = "1" Then
                    Return 1
                Else
                    '未知错误报警
                    Return 9002
                End If
            Else

                '通讯BUSY
                Return 9003
            End If
        Catch ex As Exception
            ' MsgBox(ex.Message)
            MLog.LogErrWrite(ex.ToString)
        End Try




    End Function

    Public Function GetValue(ByVal AddName As String, ByVal AddNum As Integer, ByRef RtV As Integer) As Integer

        Dim AddNumHexLen As Integer '地址16进制长度
        Dim HexAddNum As String     '地址值转到16进制
        Dim HCode As String = "@00FA000000000" '通讯表头
        Dim CommandCode As String = "0101"    '通讯命令代码
        Dim MemoryAreaCode As String          'PLC内存功能码
        Dim BitNum As String = "00"           '位读取需要写数值 0-15；字读入=0
        Dim ReadNum As String = "0001"        '读PLC地址个数；单个写入=0001
        'Dim HexValue As String                '写入数值转换为16进制
        Dim FCSString As String               '需要校验的字符串
        Dim FCSValue As String                '命令校验码
        Dim EndCode As String = "*" & vbCr    '结束码
        Dim SenCode As String                 '发送到PLC字符串
        '*************************************************************************
        '修改版本2015703 新建
        '读D数值
        '通讯发送命令
        'HCode & CommandCode & MemoryAreaCode  & HEXADDNum & BitNum & ReadNum  & FCS & EndCode
        '*************************************************************************


        Try
            If PLCBusyBit = False And OmronPLC.IsOpen Then
                PLCCommd = 1
                PLCBusyBit = True
                '选择读PLC地址类型
                Select Case AddName
                    Case "D"
                        MemoryAreaCode = "82"
                    Case Else
                        Return 1000
                        Exit Function
                End Select


                '读地址转换为HEX，计算长度是否=4；长度不够补满
                HexAddNum = Hex(AddNum)
                AddNumHexLen = HexAddNum.Length
                Select Case AddNumHexLen
                    Case 1
                        HexAddNum = "000" & HexAddNum
                    Case 2
                        HexAddNum = "00" & HexAddNum
                    Case 3
                        HexAddNum = "0" & HexAddNum
                    Case 4
                        HexAddNum = HexAddNum
                    Case Else
                        Return 1001
                        Exit Function
                End Select



                FCSString = HCode & CommandCode & MemoryAreaCode & HexAddNum & BitNum & ReadNum

                FCSValue = FinsFcsCheck(FCSString)

                SenCode = FCSString & FCSValue & EndCode
                RS232SendMsg(SenCode)
                ' Threading.Thread.Sleep(10)
                '***************************************************
                '20150608 返回结果处理

                Dim StartTick As Integer
                StartTick = Environment.TickCount
                Do
                    If (Environment.TickCount - StartTick) > 1500 Then
                        '超时报警
                        PLCBusyBit = False
                        Return 9001
                        Exit Do
                    End If

                    If PLCBusyBit = False Then

                        Exit Do
                    End If
                    Application.DoEvents()
                Loop

                If RtErrValue(0) = "1" Then
                    RtV = Convert.ToInt32(RtValue(0), 16)
                    Return 1
                Else
                    '未知错误报警
                    Return 9002
                End If
            Else

                '通讯BUSY
                Return 9003
            End If
        Catch ex As Exception
            ' MsgBox(ex.Message)
            MLog.LogErrWrite(ex.ToString)
        End Try




    End Function

    Private Sub OmronPLC_DataReceived(ByVal sender As Object, ByVal e As System.IO.Ports.SerialDataReceivedEventArgs) Handles OmronPLC.DataReceived
        Threading.Thread.Sleep(100)

        Dim ReadString As String
        If OmronPLC.IsOpen = True Then
            ReadString = OmronPLC.ReadExisting
            Call ReslutCount(ReadString)
        End If


        PLCBusyBit = False

    End Sub

    Sub ReslutCount(ByVal InputS As String)
        Dim FcsRead As String = String.Empty  '返回校验码
        Dim FcsCount As String = String.Empty '计算出校验码
        Dim RtCommand As String = String.Empty '返回命令
        Dim RtMsg As String = String.Empty '返回报警代码
        Dim OKMsg As String = "0000"        '返回正确代码
        Try
            If InputS.Length >= 25 Then
                If Mid(Microsoft.VisualBasic.Right(InputS, 2), 1, 1) = "*" Then
                    PLCRtString = Mid(InputS, 1, InputS.Length - 4)
                    FcsRead = Mid(InputS, InputS.Length - 3, 2)
                    FcsCount = FinsFcsCheck(PLCRtString)
                    RtCommand = Microsoft.VisualBasic.Mid(PLCRtString, 16, 4)
                End If

                If FcsCount = FcsRead Then

                    Select Case RtCommand
                        Case "0101"
                            RtMsg = Microsoft.VisualBasic.Mid(PLCRtString, 20, 4)
                            If RtMsg = OKMsg Then
                                '=1写入PLC值正常
                                RtValue(0) = Microsoft.VisualBasic.Mid(PLCRtString, 24, 4)
                                RtErrValue(0) = "1"
                                Exit Sub
                            End If

                        Case "0102"
                            RtMsg = Microsoft.VisualBasic.Mid(PLCRtString, 20, 4)
                            If RtMsg = OKMsg Then
                                '=1写入PLC值正常
                                RtErrValue(0) = "1"
                                Exit Sub
                            End If
                        Case Else
                            '不能识别通讯命令
                            RtErrValue(0) = "9002"
                            Exit Sub

                    End Select






                Else
                    '返回校验码不对报警
                    RtErrValue(0) = "9001"
                End If




            Else
                '返回字符串长度不够报警
                RtErrValue(0) = "9000"

            End If
        Catch ex As Exception
            MLog.LogErrWrite(ex.ToString)
        End Try
      



    End Sub

    Sub ResetErr()
        Try
            If OmronPLC.IsOpen = True Then
                OmronPLC.Close()
            End If


            If OmronPLC.IsOpen = False Then
                OmronPLC.Open()
            End If

            PLCBusyBit = False
        Catch ex As Exception
            MLog.LogErrWrite(ex.ToString)
            MsgBox(ex.Message)
        End Try

    End Sub


End Class

2015年一个项目写的 工控机 与OMRON CP1H串口通讯, 使用FAINS 能够稳定的读写数据；

      如果用HostLink通讯，FINS指令，上位机要等待PLC某些步骤准备好，就要上位机监控PLC某位是否是设定值，那就需要不断循环地发读指令，这时候串口一直在工作，上位机程序一直调用串口函数，这样会显得很繁忙，整个程序的资源都被串口收发给占用了，程序经常处在假死状态。这样的程序显然是有很大缺陷的。
      最好的解决办法当然是用中断来代替循环等待。然而，FINS指令无法让PLC主动发送就绪信号，无法提供这个中断。哪位高手有办法解决这个问题？

线程 批量读取

然而VB6是单线程的.