Why SerialEvent.RI doesn't work?

Question

Hi, I have two computers running this code:

import java.io.; import java.util.; import gnu.io.*;

public class Deb implements SerialPortEventListener, Runnable{

public static final int TIMEOUTSECONDS = 30;
public static final int BAUD = 9600;

static String telefono;
static Boolean llamar = false;

CommPortIdentifier cpiModem = null;
SerialPort modem;

BufferedReader is;
PrintStream os;

Thread hiloMarcado;

int nConnects = 0;

boolean flag = false;
String line;

public static void main(String argv[]) throws PortInUseException, UnsupportedCommOperationException, IOException, InterruptedException, TooManyListenersException {

 if (argv.length>0) {
  telefono = argv[0];
  llamar = true;
 }
 new Deb();  
}

public Deb() throws PortInUseException, UnsupportedCommOperationException, IOException, InterruptedException, TooManyListenersException{  

 Enumeration pList = CommPortIdentifier.getPortIdentifiers();
 while (pList.hasMoreElements()) {

  CommPortIdentifier cpi = (CommPortIdentifier)pList.nextElement();

  if (cpi.getPortType()==CommPortIdentifier.PORT_SERIAL) {

   SerialPort puertoSerie = (SerialPort) cpi.open("DEB", TIMEOUTSECONDS * 1000);
   puertoSerie.setSerialPortParams(BAUD, SerialPort.DATABITS_8, SerialPort.STOPBITS_1, SerialPort.PARITY_NONE);
   puertoSerie.setFlowControlMode(SerialPort.FLOWCONTROL_RTSCTS_IN & SerialPort.FLOWCONTROL_RTSCTS_OUT);

   BufferedReader is = new BufferedReader(new InputStreamReader(puertoSerie.getInputStream()));
   PrintStream os = new PrintStream(puertoSerie.getOutputStream(), true);

   os.println("AT");
   Thread.sleep(TIMEOUTSECONDS * 50);
   if (!is.ready()) {
    System.out.println("No hay un modem en " + cpi.getName());
   } else {
    System.out.println("Hay un modem en " + cpi.getName());
    cpiModem = cpi;
   }   
   puertoSerie.close();
  }   
 }

 modem = (SerialPort) cpiModem.open("DEBita", TIMEOUTSECONDS * 1000);
 modem.setSerialPortParams(BAUD, SerialPort.DATABITS_8, SerialPort.STOPBITS_1, SerialPort.PARITY_NONE);
 modem.setFlowControlMode(SerialPort.FLOWCONTROL_RTSCTS_IN & SerialPort.FLOWCONTROL_RTSCTS_OUT);

 is = new BufferedReader(new InputStreamReader(modem.getInputStream()));
 os = new PrintStream(modem.getOutputStream(), true);  

 modem.addEventListener(this);

 modem.notifyOnDataAvailable(true);
 modem.notifyOnCarrierDetect(true);
 modem.notifyOnBreakInterrupt(true);
 modem.notifyOnCTS(true);
 modem.notifyOnDSR(true);
 modem.notifyOnFramingError(true);
 modem.notifyOnOutputEmpty(true);
 modem.notifyOnOverrunError(true);
 modem.notifyOnParityError(true);
 modem.notifyOnRingIndicator(true);

 /*System.out.println(is.read());*/ 

 if (llamar) {   
  hiloMarcado = new Thread(this);
  hiloMarcado.start();
 }

}

public void serialEvent(SerialPortEvent event) {
 switch (event.getEventType()) {
 case SerialPortEvent.OE:
 case SerialPortEvent.FE:
 case SerialPortEvent.PE:
 case SerialPortEvent.DSR:
  System.out.println("Data Set Ready.");
  break;
 case SerialPortEvent.OUTPUT_BUFFER_EMPTY:
  System.out.println("Ignored event");
  break;

 case SerialPortEvent.BI:
  System.out.println("Break Interrupt");
  break;

 case SerialPortEvent.CTS:
  System.out.println("Clear to send");
  break;

 case SerialPortEvent.RI:
  System.out.println("Pick up the receiver.");
  if( event.getNewValue() ) 
  {
   System.out.println("Ring Indicator On");
  }
  else 
  {
   System.out.println("Ring Indicator Off");
  }
  break;


 case SerialPortEvent.CD:
  if (event.getNewValue()) {
   System.out.println("Connected");
   nConnects = nConnects + 1;   
  } else {
   System.out.println("Disconnected");
  }
  break;

 case SerialPortEvent.DATA_AVAILABLE: 
  handleData();
  break;
 }
}


public void run() {
 while (true) {
  if (nConnects == 0) {
   try {
    if (!modem.isCD()) {      
     System.err.println("Estamos llamando  ...");
     os.println("ATDT" + telefono);
    }
    Thread.sleep(TIMEOUTSECONDS * 2000);

   } catch (Exception ex) {
    System.err.println("Failed to write message");
   }
  }
 }
}

public void handleData() {
 try {
  int avail = modem.getInputStream().available();
  byte[] response = new byte[avail];
  StringBuffer strbuf = new StringBuffer();
  modem.getInputStream().read(response, 0, avail);


   if (!flag) {
    modem.getInputStream().read(response, 0, avail);
    for (int i = 0; i < avail; i++) {
     Thread.sleep(5);
     os.write((char) response[i]);
     System.out.print((char) response[i]);
    }
   }
 } catch (IOException ie1) {
  System.out.println("File " + ie1);
 } catch (InterruptedException in) {
  System.out.println("Interrupt " + in);
 }

}

}

It isn't the final version, I'm only seeing how it works. The thing is that when I use this code to dial to a phone number, for example, my mobile phone, it works, but it doesn't work the other way round; that is, calling from my number and acting the programme as a listener. I tried also with 2 computers, neither of them get the calls from the other end. Am I doing something wrong? I would appreciate any help.

Answer 1

I already detected the problem, it is the modem. It's an old modem I have to use while the new ones don't arrive. I tried the laptop modem on the same telephone line and everything works correctly, it detects the RI event. I suppose there is something wrong in the configuration of the modem... but I'm not sure, because it works well when receiving a fax, or when other computers phones this one using hyperterminal or simmilar programs... Does anyone know any at command that I could use to get my modem to detect RI events? Or is any other thing the problem?

Thanks

Answer 2

AT-compatible modems should send a “RING” over the data line to notify you of an incoming ring event. Maybe you could listen for that?