/// <summary>
/// <p>
/// Sends <paramref name="buf"/> byte array command to the PLC asynchronously.
/// </p>
/// <p>
/// This method returns immediately. When the response is received <paramref name="cb"/>
/// will be invoked.
/// </p>
/// </summary>
///
/// <example>
/// <code>
///
///private void ResponseHandler(IAsyncResult ar)
///{
/// PLC plc = (PLC)ar.AsyncState;
/// Response resp = plc.EndCmd(ar);
/// if (resp.String.Contains("OK!"))
/// {
/// MessageBox.Show("Run command succesfull");
/// }
/// else
/// {
/// MessageBox.Show("Run command failed");
/// }
///}
///
///private void runB_Click(object sender, EventArgs e)
///{
/// Object i = plcLB.SelectedItem;
/// if (i == null) return;
/// PLC plc = (PLC)i;
///
/// plc.BeginCmd(ASCIIEncoding.ASCII.GetBytes("run"), new AsyncCallback(ResponseHandler), plc);
///}
///
/// </code>
/// </example>
/// <param name="buf">
/// </param>/// <param name="cb">Callback to be called when the operation is complete.</param>
/// <param name="state">Any state to be passed to <paramref name="cb"/> when invoked, it's a good idea to use the PLC instance as state.</param>
/// <returns></returns>
public IAsyncResult BeginCmd(byte[] buf, AsyncCallback cb, object state)
{
log.Debug("BeginCmd");
CmdByteDelegate m_cmdFunc = Cmd;
return(m_cmdFunc.BeginInvoke(buf, cb, state));
}
/// <summary>
/// Ends a BeginCmd asynchronous call.
/// </summary>
/// <param name="ar"></param>
/// <returns>Response of the sent command</returns>
/// <seealso cref="BeginCmd"/>
public Response EndCmd(IAsyncResult ar)
{
log.Debug("EndCmd");
AsyncResult a = (AsyncResult)ar;
CmdByteDelegate d = (CmdByteDelegate)a.AsyncDelegate;
return(d.EndInvoke(ar));
}
