/// <summary>
/// Closes and destroys the com port.
/// </summary>
protected void Destroy()
{
// Cancel I/O, kill receiver & close port.
if(this.portOpen)
{
this.port.Cancel();
if(this.rxThread != null)
{
this.rxThread.Abort();
this.rxThread = null;
}
this.port.Close();
this.portOpen = false;
}
// Reinit resources.
this.dcb = null;
this.port = null;
this.stats = null;
this.props = null;
this.tmout = null;
this.rxOvr = null;
this.txOvr = null;
this.escape = null;
this.writeEvent = null;
this.recvrEvent = null;
return;
}
/// <summary>
/// Create & opens the com port and configures it with the required settings.
/// </summary>
/// <param name="cfg">Reference to port user config.</param>
/// <returns>True if port opened successfully.</returns>
protected bool Create(SerialCnfg cfg)
{
// If port already open, return.
if(portOpen)
{
this.CommError("Com Port Already Open.");
return false;
}
// Init members.
this.fault = "";
this.rxThread = null;
this.writeEvent = new ManualResetEvent(false);
this.recvrEvent = new ManualResetEvent(false);
// Copy config to DCB.
this.dcb = new Win32DCB(cfg);
// Create handle to comm port.
this.port = new Win32Com();
if((this.portOpen = this.port.Open(cfg.PortName, true)) == false)
{
this.CommError(this.port.Fault);
return false;
}
this.portName = cfg.PortName;
// Instantiate support classes.
this.stats = new Win32Status();
this.tmout = new Win32Tmout();
this.props = new Win32Props();
this.escape = new Win32Escape(port.Handle);
// Set read/write timeouts.
this.tmout.WriteConstant = cfg.TxTmoConst;
this.tmout.WriteMultiplier = cfg.TxTmoMulti;
if(this.tmout.Set(this.port.Handle) == false)
{
this.Destroy();
this.CommError(this.tmout.Fault);
return false;
}
// Overide OS default queue sizes.
if((cfg.RxQueLen != 0) || (cfg.TxQueLen != 0))
{
if(this.props.Set(this.port.Handle, (uint)cfg.RxQueLen, (uint)cfg.TxQueLen) == false)
{
this.Destroy();
this.CommError(this.props.Fault);
return false;
}
}
// Get the current properties.
if(this.props.Get(this.port.Handle) == false)
{
this.Destroy();
this.CommError(this.props.Fault);
return false;
}
// Set flow control limits.
this.dcb.Limits(cfg, this.props.RxCurSize);
// Update the port settings.
if(this.dcb.Set(this.port.Handle) == false)
{
this.Destroy();
this.CommError(this.dcb.Fault);
return false;
}
// XON/OFF extended functionality.
this.escape.XOFFavailable = true;
// RTS extended functionality.
if(cfg.RtsControl == PinState.Disable)
this.escape.RTS = false;
else if(cfg.RtsControl == PinState.Enable)
this.escape.RTS = true;
else if(cfg.RtsControl == PinState.Handshake)
this.escape.RTSavailable = false;
// DTR extended functionality.
if(cfg.DtrControl == PinState.Disable)
this.escape.DTR = false;
else if(cfg.DtrControl == PinState.Enable)
this.escape.DTR = true;
else if(cfg.DtrControl == PinState.Toggle)
this.escape.DTR = false;
else if(cfg.DtrControl == PinState.Handshake)
this.escape.DTRavailable = false;
// Create TX overlap memory pointer.
this.txOvr = new Win32Ovrlap(this.port.Handle, this.writeEvent.Handle);
// Set the receiver mode.
this.immediate = cfg.ReceiveMode;
// Start the receiver thread.
this.rxThread = new Thread(new ThreadStart(ReceiveThread));
this.rxThread.Name = "COMReceiver";
this.rxThread.Priority = ThreadPriority.AboveNormal;
this.rxThread.Start();
// Wait for receive thread to start.
this.recvrEvent.WaitOne(500, false);
// Port opened OK.
return true;
}