RS-232 通訊讀取

對一個初學者來說, RS-232 通訊是一件苦差事. 從最早的 MSCOMM 到 .Net FrameWork 之後, 語法變更十分巨大. 因此如果您也是從組合語言起家的. 那進入 .Net FrameWork 之後, 你會完全不知道該怎麼辦. 下面的程式. 為基本 RS-232 通訊, 並與台灣 TCBUS 連接的範例. 程式碼如下. 其實, 最大的分別點只有. "當COM PORT 傳回資料時" 進行讀取, 使用"委派" 讓程式得以在多工下執行. 並沒有什麼其他的困難點, 而 TCBUS 最後的結尾字元為 0x13h 所以只需要大方的. serialPort.WriteLine(cmd) 就完事了. 如果通訊方式非以換行字元為主, 那請參考前部落格的方式. 以陣列方式填入即可. Imports System Imports System.ComponentModel Imports System.Threading Imports System.Windows.Forms Imports System.Net.Sockets Imports System.Net Imports System.Text Public Class Form1 Public Shared ports As String() = IO.Ports.SerialPort.GetPortNames() Public Shared myport As String Public read_flag As Boolean Public mystring As String Public m_length As Integer Public m_arRxBfx(25) As Byte Public buffer_string As String Public m_arTxBfx(25) As Byte Delegate Sub PrintToText(ByVal InputString As String) Private Sub ShowText(ByVal strReceive As String) If Me.response.InvokeRequired Then Dim d As New PrintToText(AddressOf ShowText) Me.Invoke(d, New Object() {strReceive}) Else Me.response.Text += mystring End If End Sub Delegate Sub findport(ByVal InputString As String) Public Shared Sub showport(ByVal strReceive As String) If Form1.response.InvokeRequired Then Dim d As New findport(AddressOf showport) Form1.Invoke(d, New Object() {strReceive}) Else For Each port In ports ' listBox1.Items.Add("Item " & x.ToString()) Form1.PortUsed.Items.Add(port) myport = port Next Form1.PortUsed.SelectedIndex = 0 End If 'Form1.PortUsed.SetSelected(1, True) End Sub Private WithEvents serialPort As New IO.Ports.SerialPort Dim sent_string(24) As Array Dim register As Byte Dim command As Byte Dim station As Byte Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click Call P_learn() End Sub Public Sub Connect(ByVal PortNo As String) If PortNo = "" Then PortNo = myport End If If serialPort.IsOpen Then serialPort.Close() End If Try With serialPort .PortName = PortNo .BaudRate = 38400 .Parity = IO.Ports.Parity.None .DataBits = 8 .StopBits = IO.Ports.StopBits.One .Handshake = IO.Ports.Handshake.None End With serialPort.Open() Catch ex As Exception End Try End Sub Private Sub mySerialPort_DataReceived(ByVal sender As Object, _ ByVal e As System.IO.Ports.SerialDataReceivedEventArgs) _ Handles serialPort.DataReceived read_flag = True mystring = "" m_length = serialPort.BytesToRead If m_length Mod 25 = 0 Then mystring = serialPort.ReadExisting + Chr(10) ShowText("OK") Else Thread.Sleep(1000) End If read_flag = False End Sub Private Sub P_learn(ByVal cmd As String) Connect(myport) serialPort.WriteLine(cmd) End Sub Private Sub P_send(ByVal cmd As String) Connect(myport) serialPort.WriteLine(cmd) End Sub Private Sub Button2_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button2.Click P_send() End Sub Private Sub CircuitName_SelectedIndexChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles CircuitName.HandleCreated Dim count As String For i = 0 To 99 If i < 10 Then count = "0" + i.ToString Else count = i.ToString End If CircuitName.Items.Add(count) Next End Sub Protected Overrides Sub OnLoad(ByVal e As EventArgs) showport("OK") End Sub Private Sub P_learn() MsgBox("沒有字串") End Sub Private Sub P_send() MsgBox("沒有字串") End Sub Private Sub Button3_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles ReadAll.Click Dim cmd As String = "*C0009FEFF00FF0200000000" response.Text = "" RSCommand.Text = cmd P_send(cmd) End Sub Private Sub SendCommand_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles SendCommand.Click Dim cmd As String cmd = RSCommand.Text P_send(cmd) End Sub Private Sub Attrib_TextChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Attrib.HandleCreated If Attrib.Text = "" Then Attrib.Text = "0" End If End Sub Private Sub PlusAttrib_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles PlusAttrib.Click Dim a As Integer a = Attrib.Text a = a + 1 Attrib.Text = a End Sub Private Sub MinusAttrib_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MinusAttrib.Click Dim a As Integer a = Attrib.Text a = a - 1 Attrib.Text = a End Sub Private Sub OnCmd_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles OnCmd.Click Dim st As Integer Dim c As Integer Dim precmd As String = "*C00190E0100" Dim midcmd As String = "01" Dim endcmd As String = "000000A" Dim st_string As String st = StationName.SelectedItem c = Attrib.Text st_string = Hex(st) If st_string.Length = 1 Then st_string = "0" + st_string End If st_string = precmd + st_string + midcmd + c.ToString + endcmd RSCommand.Text = st_string End Sub Private Sub StationName_init(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles StationName.HandleCreated For i = 10 To 99 StationName.Items.Add(i) Next StationName.SelectedIndex = 0 End Sub End Class