VB COMM通信

Private Sub MSC_OnComm()

  With MSC

  Select Case .CommEvent ′判断通信事件

  Case comEvReceive: ′收到Rthreshold个字节产生的接收事件

  If Out(1) = 2 Then ′判断是否为数据的开始标志

  .RThreshold = 0 ′关闭OnComm事件接收

  End If

  Do

  DoEvents

  Loop Until .InBufferCount >= 3 ′循环等待接收缓冲区>=3个字节

  Text1.Text = LTrim(Text1.Text)

  Text2.Text = Text2.Text & CStr(nRece)

  .RThreshold = 1 ′打开MSComm事件接收

  Case Else

′ .PortOpen = False

  End Select

  End With

End Sub


帮分析下接收流程

http://download.csdn.net/detail/veron_04/1262066