繁体   English   中英

从连接了USB-> RS232的终端接收数据

[英]Receiving data from Terminal connected with USB->RS232

我正在开发一个Java应用程序,该应用程序需要与通过usb-to-rs232转换器连接的终端进行通信!!

现在,我可以连接设备并发送数据了! 我可以确定终端接收到了发送的数据,因为当终端接收到某些东西时,LED会发光!

我正在使用JSSC (链接: https : //code.google.com/p/java-simple-serial-connector/wiki/jSSC_examples )...但是由于某些原因,我从来没有从终端接收过任何数据。

我的代码(JSSC代码):

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");
              }
         }
    }
}
}

谁能帮我解决这个问题?

您打算将硬件流控制与USB-UART一起使用吗? 如果是,请尝试先设置DTR,再设置RTS。 这告诉第一端第二端已准备好进行通信。 此外,没有接收到10个字节或根本没有接收到数据。 还要考虑另一个串行端口通信库,例如scm http://www.embeddedunveiled.com/

暂无
暂无

声明:本站的技术帖子网页,遵循CC BY-SA 4.0协议,如果您需要转载,请注明本站网址或者原文地址。任何问题请咨询:yoyou2525@163.com.

 
粤ICP备18138465号  © 2020-2024 STACKOOM.COM