public bool Zero(int milliSenconds) { int timeout = 0; if (ANDserial == null) { return(false); } ANDserial.SendMessage("R\r\n"); while (String.IsNullOrEmpty(ANDserial.SendBackMessageIntime("Q\r\n", 100)) && timeout < milliSenconds / 100) { Thread.Sleep(5); timeout++; } if (timeout >= milliSenconds / 100) { return(false); } else { return(true); } }