串行端口在带有打包消息的VB.NET中发送数据

Question

我有《编程手册》协议的手册，但是在编写代码时，vb.net返回错误消息。

以下是字节数组的表结构

位置1 2 3 4 5 6 7 8

名称SOH LEN SEQ CMD DATA后同步码BCC ETX

长度/字节1 1 1 1 0-200 1 4 1

值（01h）（20h-FFh）（20h-FFh）（20h-FFh）（20h-FFh）（05h）（30h-3Fh）（03h）

缩略语：

“ SOH” -（标题开始）打包消息的开始

“ LEN” -从位置2到位置6的字节总数，加上20h的固定偏移量。

“ SEQ” -数据包的序列号。 SLAVE在回复消息中放置相同的“ SEQ”。 如果SLAVE接收到的消息与上次正确接收的消息一样具有相同的“ SEQ”和“ CMD”，则设备将忽略该消息并重复发送到主机的最后一个数据包。

“ CMD” –命令代码

“ DATA” -数据，根据命令。 如果没有数据，则长度字段为零。

“ BCC” –控制和（0000h-FFFFh）。 从位置2到位置6的数据字节总和。控制总和以ASCІІ类型传输（12АВ作为31h 32h3Аh3Вh传输）。

“ ETX” –（TeXt的结尾）打包消息的结尾。

代码示例：

公开课表格1

Private WithEvents sp As System.IO.Ports.SerialPort

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

    For Each y As String In System.IO.Ports.SerialPort.GetPortNames
        Me.ComboBox1.Items.Add(y)
    Next
    sp = New IO.Ports.SerialPort("COM4")
    sp.StopBits = IO.Ports.StopBits.One
    sp.BaudRate = 9600
    sp.DataBits = 8
    sp.Parity = IO.Ports.Parity.None
    sp.Handshake = IO.Ports.Handshake.None

    sp.Open()
    Dim by As Byte = &H20

    ' MsgBox(&H20)
End Sub

Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
    Try
        Dim By(9) As Byte
        By(0) = 1
        By(1) = &H2 + &H20
        By(2) = &H58
        By(3) = &H45
        By(4) = &H5
        Dim S As String = Hex(&H58 Xor &H45)
        '  MsgBox(S)
        By(5) = &H30
        By(6) = &H30
        By(7) = &H31
        By(8) = &H3D
        By(9) = &H3

        sp.Write(By, 0, By.Length - 1)
       ' MsgBox(sp.ReadByte)
    Catch ex As Exception
        MsgBox(ex.Message)
    End Try
End Sub

Private Sub sp_DataReceived(ByVal sender As Object, ByVal e As System.IO.Ports.SerialDataReceivedEventArgs) Handles sp.DataReceived
    Dim rec As System.IO.Ports.SerialPort = sender
    MsgBox(Hex(rec.ReadByte))
End Sub

末级

Answer 1

Annael您可以通过调用更新功能并提供500ms的延迟来做到这一点。 现在，在接收数据时，您可以接收输入数据

Dim inputData As String = ""// Declare this as a global variable in the program
    Private WithEvents sp As System.IO.Ports.SerialPort

    Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
   For Each y As String In System.IO.Ports.SerialPort.GetPortNames
            Me.ComboBox1.Items.Add(y)//the code you have written to add Serial ports

SerialPort1.PortName = ComboBox1.Text//this will access your com port as your button
        Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
        Dim by As Byte = &H20    
                By(0) = 1
                By(1) = &H2 + &H20
                By(2) = &H58
                By(3) = &H45
                By(4) = &H5
                Dim S As String = Hex(&H58 Xor &H45)
                '  MsgBox(S)
                By(5) = &H30
                By(6) = &H30
                By(7) = &H31
                By(8) = &H3D
                By(9) = &H3
            SerialPort1.BaudRate = 115200
            SerialPort1.Open()
            SerialPort1.Write(By)
        Private Sub SerialPort1_DataReceived(sender As System.Object, e As System.IO.Ports.SerialDataReceivedEventArgs) Handles SerialPort1.DataReceived

            Threading.Thread.Sleep(500) ' 500ms delay induced to receive the email
            inputData = SerialPort1.ReadExisting 'or SerialPort1.ReadLine


            Me.Invoke(New EventHandler(AddressOf DoUpdate))

    Public Sub DoUpdate()

                MsgBox(inputData)