Question

我有一个简单的vb.net程序，我正在尝试发送FINS命令并使用UDP接收响应。我一直在使用以下问题作为参考点FINS Commands C#，但我相信我的数据包出了问题，或者我可能没有完全正确的事情。

我当前的程序有4个文本框（TBIP，TBPORT，TBSEND，TBReceive）。当我运行程序时，我输入要发送的IP，端口，数据包信息，然后单击一个按钮。我希望发生的是收到TBReceive的信息。

我的表单加载代码如下所示：

Dim publisher As New Sockets.UdpClient(0)
Dim Subsriber As New Sockets.UdpClient(9600)

Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load

        Subsriber.Client.ReceiveTimeout = 5000
        Subsriber.Client.Blocking = False


    End Sub

我的按钮点击：

Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
        publisher.Connect(TBIP.Text, TBPort.Text)
        Dim Sendbytes() As Byte = ASCII.GetBytes(TBSend.Text)
        publisher.Send(Sendbytes, Sendbytes.Length)

        Subsriber.Client.Blocking = True


        Timer1.Start()

    End Sub

我的计时器：

Private Sub Timer1_Tick(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Timer1.Tick
        Try
            Dim ep As IPEndPoint = New IPEndPoint(IPAddress.Any, 0)
            Dim rcvbytes As [Byte]() = Subsriber.Receive(ep)
            Dim returndata As String = ASCII.GetString(rcvbytes)

            TBReceive.Text = returndata.ToString

        Catch ex As Exception
            MsgBox(ex.Message)
        End Try
    End Sub
End Class

在欧姆龙PLC上，我正在尝试读取CIO 100.我的IP地址是10.0.1.91所以我的字符串在下面。（5B是最后一个八位字节）：

80 00 02 01 02 00 01 5B 00 12 01 01 00 00 12 34

我在HEX位之间添加了空格，以便于阅读。

第一个问题可能是我转换为或尝试将信息作为ASCII发送？任何帮助将不胜感激。

Answer 1

Hex适用于人类，您的PLC将需要二进制数据。您需要在要在TextBox中输入的“800002010200015B0012010100001234”十六进制字符串和PLC喜欢的二进制字节之间进行转换。您可以使用的示例代码：

Module HexConversions
    Public Function HexToBinary(hex As String) As Byte()
        hex = hex.Replace(" ", "")
        If hex.Length mod 2 <> 0 then Throw New FormatException 
        Dim bytes = hex.Length \ 2 - 1
        Dim bin(bytes) As Byte
        For ix As Integer = 0 to bytes
            bin(ix) = Byte.Parse(hex.Substring(ix * 2, 2), Globalization.NumberStyles.HexNumber)
        Next
        Return bin
    End Function

    Public Function BinaryToHex(bytes() As Byte, Optional usespace As Boolean = False) As String
        Dim hex = BitConverter.ToString(bytes)
        Return hex.Replace("-", IIf(usespace, " ", ""))
    End Function
End Module

您在现有代码中使用的内容如下：

    Try         
        Dim Sendbytes() As Byte = HexConverter.HexToBinary(TBSend.Text)
        publisher.Send(Sendbytes, Sendbytes.Length)
    Catch ex As FormatException
        MessageBox.Show("Please enter a valid hex string")
        TBSend.Focus()
        TBSend.SelectAll()
    End Try

和

    Dim rcvbytes() As Byte = Subsriber.Receive(ep)
    TBReceive.Text = HexConverter.BinaryToHex(rcvbytes, True)

从VB.net向PLC发送FINS命令

1 个答案: