從連接了USB-> RS232的終端接收數據

Question

我正在開發一個Java應用程序，該應用程序需要與通過usb-to-rs232轉換器連接的終端進行通信！！

現在，我可以連接設備並發送數據了！ 我可以確定終端接收到了發送的數據，因為當終端接收到某些東西時，LED會發光！

我正在使用JSSC （鏈接： https : //code.google.com/p/java-simple-serial-connector/wiki/jSSC_examples ）...但是由於某些原因，我從來沒有從終端接收過任何數據。

我的代碼（JSSC代碼）：

public class Main
{

    static SerialPort serialPort;

    public static void main(String[] args) throws InterruptedException
    {
        serialPort = new SerialPort("COM7"); 
        try
        {
             serialPort.openPort();//Open port
             serialPort.setParams(9600, 8, 1, 0);//Set params
             int mask = SerialPort.MASK_RXCHAR + SerialPort.MASK_CTS + SerialPort.MASK_DSR;//Prepare mask
             serialPort.setEventsMask(mask);//Set mask
             serialPort.addEventListener(new SerialPortReader());//Add SerialPortEventListener

             serialPort.writeByte( (byte)0x02 );

             TimeUnit.SECONDS.sleep( 10 );

             byte[] b = serialPort.readBytes();
             System.out.println( "bytes " + b );
        }
        catch (SerialPortException ex)
        {
             System.out.println(ex);
        }
}

/*
 * In this class must implement the method serialEvent, through it we learn about 
 * events that happened to our port. But we will not report on all events but only 
 * those that we put in the mask. In this case the arrival of the data and change the 
 * status lines CTS and DSR
 */
static class SerialPortReader implements SerialPortEventListener
{
    public void serialEvent(SerialPortEvent event)
    {
         System.out.println( "Event raised!" );
         if(event.isRXCHAR())
         {//If data is available
              if(event.getEventValue() == 10)
              {//Check bytes count in the input buffer
              //Read data, if 10 bytes available 
                   try
                   {
                        byte buffer[] = serialPort.readBytes(10);
                   }
                   catch (SerialPortException ex)
                   {
                        System.out.println(ex);
                   }
              }
         }
         else if(event.isCTS())
         {//If CTS line has changed state
              if(event.getEventValue() == 1)
              {//If line is ON
                  System.out.println("CTS - ON");
              }
              else
              {
                   System.out.println("CTS - OFF");
              }
         }
         else if(event.isDSR())
         {///If DSR line has changed state
              if(event.getEventValue() == 1)
              {//If line is ON
                  System.out.println("DSR - ON");
              }
              else
              {
                   System.out.println("DSR - OFF");
              }
         }
    }
}
}

誰能幫我解決這個問題？

Answer 1

您打算將硬件流控制與USB-UART一起使用嗎？ 如果是，請嘗試先設置DTR，再設置RTS。 這告訴第一端第二端已准備好進行通信。 此外，沒有接收到10個字節或根本沒有接收到數據。 還要考慮另一個串行端口通信庫，例如scm http://www.embeddedunveiled.com/