最近在研究VB跟歐姆龍CP1H的通信.了解到可以用串口進行HOSTLINK通信,還可以用以太網(wǎng)進行FANS通信.CP1H沒有網(wǎng)口所以不可以用FANS通信嗎?串口通信情況下,PLC處于運行時寫入不了數(shù)據(jù),只有當PLC是監(jiān)控狀態(tài)時才能寫入.這怎么能達到隨時寫入的目的呢?

將PLC的運行模式改為監(jiān)控模式就行了!

研究了幾天,終于明白,FINS協(xié)議也可以通過串口和PLC通信上

      FINS通訊命令，0401可以讓PLC進入運行/監(jiān)控模式，0402可以讓PLC進入停止模式。
      實測用0402讓PLC停止后還可以用0101和0102對DM區(qū)進行讀寫。
      另：串口的hostlink模式FINS命令只能上位機控制PLC，PLC無法主動發(fā)數(shù)據(jù)給上位機。通過看w227文件，發(fā)現(xiàn)FINS幀格式自由度比較高，理論上來講可以通過修改幀里面的命令符進行PLC通過串口對上位機發(fā)送數(shù)據(jù)，就好像用以太網(wǎng)發(fā)送一樣。但是歐姆龍PLC說明書里面并沒這方面的介紹。目前來說，PLC通過串口主動發(fā)數(shù)據(jù)給上位機發(fā)送數(shù)據(jù)要用無協(xié)議通訊。但是無協(xié)議通訊的話上位機無法控制PLC的開關狀態(tài)。小弟剛學歐姆龍通訊，好多東西還不懂，望論壇各位前輩不吝賜教。

不用PLC發(fā),上位機不斷的讀取就可以了.FINS協(xié)議是最好的.在運行時可以對PLC進行讀,寫操作.HOSTLINK在PLC運行時可以讀,但要寫入必須把PLC改成監(jiān)控模式,太煩.

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通訊計算校驗碼
    ''' </summary>
    ''' <param name="Value">傳入需要校驗內容</param>
    ''' <returns>返回Fins校驗值</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
    ''' 寫單個PLC值函數(shù)
    '''
    ''' </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進制長度
        Dim HexAddNum As String     '地址值轉到16進制
        Dim HCode As String = "@00FA000000000" '通訊表頭
        Dim CommandCode As String = "0102"    '通訊命令代碼
        Dim MemoryAreaCode As String          'PLC內存功能碼
        Dim BitNum As String = "00"           '位寫入需要寫數(shù)值 0-15；字寫如=0
        Dim WriteNum As String = "0001"        '寫PLC地址個數(shù)；單個寫入=0001
        Dim HexValue As String                '寫入數(shù)值轉換為16進制
        Dim FCSString As String               '需要校驗的字符串
        Dim FCSValue As String                '命令校驗碼
        Dim EndCode As String = "*" & vbCr    '結束碼
        Dim SenCode As String                 '發(fā)送到PLC字符串
        '*************************************************************************
        '修改版本20150526 新建
        '寫入數(shù)值到D
        '通訊發(fā)送命令
        'HCode & CommandCode & MemoryAreaCode  & HEXADDNum & BitNum & WriteNum & Value & FCS & EndCode
        '*************************************************************************


        Try
            If PLCBusyBit = False And OmronPLC.IsOpen Then
                PLCCommd = 1
                PLCBusyBit = True
                '選擇寫入PLC地址類型
                Select Case AddName
                    Case "D"
                        MemoryAreaCode = "82"
                    Case Else
                        Return 1000
                        Exit Function
                End Select


                '寫入地址轉換為HEX，計算長度是否=4；長度不夠補滿
                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

                '寫入數(shù)值轉換位16進制，計算長度=4；長度不夠布滿
                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 返回結果處理

                Dim StartTick As Integer
                StartTick = Environment.TickCount
                Do
                    If (Environment.TickCount - StartTick) > 1500 Then
                        '超時報警
                        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
                    '未知錯誤報警
                    Return 9002
                End If
            Else

                '通訊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進制長度
        Dim HexAddNum As String     '地址值轉到16進制
        Dim HCode As String = "@00FA000000000" '通訊表頭
        Dim CommandCode As String = "0101"    '通訊命令代碼
        Dim MemoryAreaCode As String          'PLC內存功能碼
        Dim BitNum As String = "00"           '位讀取需要寫數(shù)值 0-15；字讀入=0
        Dim ReadNum As String = "0001"        '讀PLC地址個數(shù)；單個寫入=0001
        'Dim HexValue As String                '寫入數(shù)值轉換為16進制
        Dim FCSString As String               '需要校驗的字符串
        Dim FCSValue As String                '命令校驗碼
        Dim EndCode As String = "*" & vbCr    '結束碼
        Dim SenCode As String                 '發(fā)送到PLC字符串
        '*************************************************************************
        '修改版本2015703 新建
        '讀D數(shù)值
        '通訊發(fā)送命令
        'HCode & CommandCode & MemoryAreaCode  & HEXADDNum & BitNum & ReadNum  & FCS & EndCode
        '*************************************************************************


        Try
            If PLCBusyBit = False And OmronPLC.IsOpen Then
                PLCCommd = 1
                PLCBusyBit = True
                '選擇讀PLC地址類型
                Select Case AddName
                    Case "D"
                        MemoryAreaCode = "82"
                    Case Else
                        Return 1000
                        Exit Function
                End Select


                '讀地址轉換為HEX，計算長度是否=4；長度不夠補滿
                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 返回結果處理

                Dim StartTick As Integer
                StartTick = Environment.TickCount
                Do
                    If (Environment.TickCount - StartTick) > 1500 Then
                        '超時報警
                        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
                    '未知錯誤報警
                    Return 9002
                End If
            Else

                '通訊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  '返回校驗碼
        Dim FcsCount As String = String.Empty '計算出校驗碼
        Dim RtCommand As String = String.Empty '返回命令
        Dim RtMsg As String = String.Empty '返回報警代碼
        Dim OKMsg As String = "0000"        '返回正確代碼
        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寫入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寫入PLC值正常
                                RtErrValue(0) = "1"
                                Exit Sub
                            End If
                        Case Else
                            '不能識別通訊命令
                            RtErrValue(0) = "9002"
                            Exit Sub

                    End Select






                Else
                    '返回校驗碼不對報警
                    RtErrValue(0) = "9001"
                End If




            Else
                '返回字符串長度不夠報警
                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年一個項目寫的 工控機 與OMRON CP1H串口通訊, 使用FAINS 能夠穩(wěn)定的讀寫數(shù)據(jù)；

      如果用HostLink通訊，F(xiàn)INS指令，上位機要等待PLC某些步驟準備好，就要上位機監(jiān)控PLC某位是否是設定值，那就需要不斷循環(huán)地發(fā)讀指令，這時候串口一直在工作，上位機程序一直調用串口函數(shù)，這樣會顯得很繁忙，整個程序的資源都被串口收發(fā)給占用了，程序經(jīng)常處在假死狀態(tài)。這樣的程序顯然是有很大缺陷的。
      最好的解決辦法當然是用中斷來代替循環(huán)等待。然而，F(xiàn)INS指令無法讓PLC主動發(fā)送就緒信號，無法提供這個中斷。哪位高手有辦法解決這個問題？

線程 批量讀取

然而VB6是單線程的.