serial port

While(!islabelprinted|| !isendofbatch)
{}
islabelprinted = false;
isendofbatch = false;

1Begin **********05:52:50.468
05:52:50.484DO Write() 1
05:52:50.531 Write() 1
05:52:50.765 DataReceived: Label printed
05:52:50.781 DataReceived: batch end
05:52:50.781 I=1 Получили ответ :time1=0,2499968sec; islabelprinted=True; isendofbatch=True
1End**********05:52:50.781 Total = 0,3124992sec;
2Begin **********05:52:50.781
05:52:50.781DO Write() 2
05:52:50.828 Write() 2
05:52:51.46 DataReceived: Label printed
05:52:51.62 DataReceived: batch end
05:52:51.62 I=2 Получили ответ :time1=0,2343808sec; islabelprinted=True; isendofbatch=True
2End**********05:52:51.62 Total = 0,2812544sec;
3Begin **********05:52:51.62
05:52:51.62DO Write() 3
05:52:51.93 Write() 3
05:52:51.328 DataReceived: Label printed
05:52:51.328 DataReceived: batch end
05:52:51.328 I=3 Получили ответ :time1=0,2343808sec; islabelprinted=True; isendofbatch=True
3End**********05:52:51.328 Total = 0,2656256sec;

            port = new SerialPort("COM1", 38400, Parity.None, 8, StopBits.One);
            port.Handshake = Handshake.RequestToSend;
            port.Encoding = System.Text.Encoding.GetEncoding(1251);
            port.DataReceived += new SerialDataReceivedEventHandler(SerialPort_DataReceived);
            if (!port.IsOpen)
                port.Open();
 
 
        void SerialPort_DataReceived(object sender, SerialDataReceivedEventArgs e)
        {
                string s = port.ReadExisting();
                if (s.IndexOf((char)30) != -1)
                {
                    islabelprinted = true;
                    Console.WriteLine(DateTime.Now.ToString("hh:mm:ss") + "." + DateTime.Now.Millisecond.ToString() + " DataReceived: Label printed");
                }
                if (s.IndexOf((char)31) != -1)
                {
                    isendofbatch = true;
                    Console.WriteLine(DateTime.Now.ToString("hh:mm:ss") + "." + DateTime.Now.Millisecond.ToString() + " DataReceived: batch end");
                }
        }

20  9:52:10 WindowsFormsApp IOCTL_SERIAL_SET_BAUD_RATE  Serial0 SUCCESS Rate: 38400 
21  9:52:10 WindowsFormsApp IOCTL_SERIAL_CLR_DTR    Serial0 SUCCESS     
22  9:52:10 WindowsFormsApp IOCTL_SERIAL_SET_LINE_CONTROL   Serial0 SUCCESS StopBits: 1 Parity: NONE WordLength: 8  
23  9:52:10 WindowsFormsApp IOCTL_SERIAL_SET_CHAR   Serial0 SUCCESS EOF:1a ERR:0 BRK:0 EVT:1a XON:11 XOFF:13    
24  9:52:10 WindowsFormsApp IOCTL_SERIAL_SET_HANDFLOW   Serial0 SUCCESS Shake:8 Replace:80 XonLimit:1024 XoffLimit:1024 
25  9:52:10 WindowsFormsApp IOCTL_SERIAL_CLR_DTR    Serial0 SUCCESS     
26  9:52:10 WindowsFormsApp IOCTL_SERIAL_SET_TIMEOUTS   Serial0 SUCCESS RI:-1 RM:-1 RC:-2 WM:0 WC:0 
27  9:52:10 WindowsFormsApp IOCTL_SERIAL_SET_WAIT_MASK  Serial0 SUCCESS Mask: RXCHAR RXFLAG CTS DSR RLSD BRK ERR RING   
28  9:52:10 WindowsFormsApp IOCTL_SERIAL_SET_QUEUE_SIZE Serial0 SUCCESS InSize: 4096 OutSize: 2048  
29  9:52:10 WindowsFormsApp IOCTL_SERIAL_WAIT_ON_MASK   Serial0

5   0.00000168  DelphiApp.exe   IOCTL_SERIAL_GET_HANDFLOW   Serial0 SUCCESS     
6   0.00000922  DelphiApp.exe   IOCTL_SERIAL_SET_BAUD_RATE  Serial0 SUCCESS Rate: 38400 
7   0.00000447  DelphiApp.exe   IOCTL_SERIAL_CLR_DTR    Serial0 SUCCESS     
8   0.00000307  DelphiApp.exe   IOCTL_SERIAL_SET_LINE_CONTROL   Serial0 SUCCESS StopBits: 1 Parity: NONE WordLength: 8  
9   0.00000168  DelphiApp.exe   IOCTL_SERIAL_SET_CHAR   Serial0 SUCCESS EOF:1 ERR:40 BRK:40 EVT:0 XON:11 XOFF:13    
10  0.00000978  DelphiApp.exe   IOCTL_SERIAL_SET_HANDFLOW   Serial0 SUCCESS Shake:8 Replace:80 XonLimit:1024 XoffLimit:1024 
11  0.00000140  DelphiApp.exe   IOCTL_SERIAL_SET_TIMEOUTS   Serial0 SUCCESS RI:-1 RM:0 RC:0 WM:100 WC:1000  
12  0.00000503  DelphiApp.exe   IOCTL_SERIAL_SET_WAIT_MASK  Serial0 SUCCESS Mask: RXCHAR RXFLAG TXEMPTY CTS DSR RLSD BRK ERR RING RX80FULL