vb.net - 串口读取包括vb.net中已经写入的内容

Question

因此，我尝试使用 AT 命令与 gsm 调制解调器通信，我尝试进行基本测试，通过发送命令 AT 并接收 OK 来确保调制解调器正常。问题是我收到“AT Blank Line OK”，有什么方法可以让我发送 AT 时只读取 OK 吗？

Imports System.IO.Ports

Public Class GUI
Dim Device As New System.IO.Ports.SerialPort()
Private Sub GUI_Load(ByVal sender As System.Object, ByVal e As System.EventArgs)         Handles MyBase.Load
    Port.Text = "Select Port"
    For Each item As String In IO.Ports.SerialPort.GetPortNames
        Port.Items.Add(item)
    Next
    Device.BaudRate = 9600
    Device.Parity = Parity.None
    Device.StopBits = StopBits.One
    Device.DataBits = 8
    Device.Handshake = Handshake.RequestToSend
    Device.DtrEnable = True
    Device.RtsEnable = True
    Device.NewLine = vbCrLf
    Device.WriteTimeout = 5000
End Sub

Private Sub Port_SelectedIndexChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Port.SelectedIndexChanged
    Device.PortName = Port.SelectedItem.ToString
End Sub

Private Sub Send_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Send.Click
    Try
        Device.Open()
        Dim msg As String
        msg = Message.Text
        Device.DiscardInBuffer()
        Device.DiscardOutBuffer()
        Device.Write("AT" & vbCrLf)
        MsgBox(Device.ReadExisting())
    Catch ex As Exception
        MsgBox("Error!")
    End Try
    Device.Close()
End Sub
End Class

Answer 1

听起来调制解调器已设置为回显命令。要关闭此功能，请先尝试发送 E0。

More info here