c++ - Wince 6.0 串口配置

Question

我正在使用 WinCE 6.0 设备进行串行通信。它有4个串口，我用的是2个，一个是RS232的，一个是RS485的。配置为 RS232 的串口工作正常，但 RS485 通信不工作 下面是代码，

int MbusSerialSlaveProtocol::startupServer(int slaveAddr,
                                       const TCHAR * const portName,
                                       long baudRate, int dataBits,
                                       int stopBits, int parity)
{
   int result;

   TRACELOG2("Open port: %d \n", portName);
   TRACELOG5("Parameters: %d, %d, %d, %d\n",
             baudRate, dataBits, stopBits, parity);
   TRACELOG2("Configuration: %d\n", timeOut);

   if (isStarted())
      return (FTALK_ILLEGAL_STATE_ERROR);

   if ((slaveAddr <= 0) || (slaveAddr > 255))
      return (FTALK_ILLEGAL_ARGUMENT_ERROR);
   this->slaveAddr = slaveAddr;

   if ((dataBits != SerialPort::SER_DATABITS_7) &&
       (dataBits != SerialPort::SER_DATABITS_8))
      return(FTALK_ILLEGAL_ARGUMENT_ERROR);

   // Close an existing connection
   if (serialPort.isOpen())
      serialPort.closePort();

   result = serialPort.openPort(portName);
   if (result == SerialPort::SER_PORT_NO_ACCESS)
      return(FTALK_PORT_NO_ACCESS);
   if (result == SerialPort::SER_ALREADY_OPEN)
      return(FTALK_PORT_ALREADY_OPEN);
   if (result != SerialPort::SER_SUCCESS)
      return(FTALK_OPEN_ERR);
   result = serialPort.config(baudRate, dataBits,
                              stopBits, parity,
                              SerialPort::SER_HANDSHAKE_NONE);
   if (result != SerialPort::SER_SUCCESS)
   {
      serialPort.closePort();
      return(FTALK_ILLEGAL_ARGUMENT_ERROR);
   }
   if (serialMode == SER_RS485)
      serialPort.clearRts();
   return (FTALK_SUCCESS);
}
int main()
{

    protocol = new ModbusSerialSlave(dataTable);
        int test = atce_uart_set_interface(6, 485);
        //result = 

    ((ModbusSerialSlave*)protocol)->startupServer(01,_T("COM6:"),19200,8,1,0);
            ((ModbusSerialSlave*)protocol)->enableRs485Mode(10);
            result = ((ModbusSerialSlave*)protocol)->startupServer(01,_T("COM6:"),port.nBaudRate,port.nDataBit,port.nStopBit,port.nParity);
while(1)
{
protocol->serverLoop();
}

}

////////////////////////////////////////////////////////////////////我将 RTS 信号更改为切换状态，但仍然无法正常工作。我将 RTS 延迟增加到 1000，尝试发送数据设备但没有得到结果。端口打开或参数设置没有错误，我通过将错误消息写入文件来监视它们。这是端口打开和配置的代码。

int SerialPort::openPort(const TCHAR * const portName)
{
ofstream config_file(TEST_FILE_NAME3);

   if (isOpen())
   {
       config_file.write("open1",5);
      closePort();
   }
   port = CreateFile(portName, GENERIC_READ | GENERIC_WRITE, 0, NULL,
                     OPEN_EXISTING, 0, NULL);
   if (port == INVALID_HANDLE_VALUE)
   {
      switch (GetLastError())
      {
         case ERROR_FILE_NOT_FOUND:
             {
                 config_file.write("open2",5);
         return (SER_PORT_NOT_FOUND);
             }
         case ERROR_ACCESS_DENIED:
             {
                 config_file.write("open3",5);
         return (SER_ALREADY_OPEN);
             }
         default:
             {
                 config_file.write("open4",5);
         return (SER_API_ERROR);
             }
      }
   }
//  SetupComm(port, 256, 256); //ttt
   // Save current device control block
   if (!GetCommState(port, &savedDevCtrlBlock))
   {
       config_file.write("open5",5);
      return (SER_API_ERROR);
   }
   this->flush(); // Needed on QNX 6 to clear a filled buffer
   config_file.write("open6",5);

   return (config(19200, SER_DATABITS_8, SER_STOPBITS_1,
           SER_PARITY_NONE, SER_HANDSHAKE_NONE));
}



int SerialPort::config(long baudRate, int dataBits,
                       int stopBits, int parity, int flowControl)
{
   DCB devCtrlBlock;
 ofstream config_file(TEST_FILE_NAME);
   if (!isOpen())
   {
        config_file.write("Line1",5);
      return (SER_NOT_OPEN);
   }

   //
   // Retrieve current device control block
   //
   if (!GetCommState(port, &devCtrlBlock))
   {
        config_file.write("Line2",5);
      return (SER_API_ERROR);
   }

   //
   // Modify device control block
   //
   devCtrlBlock.BaudRate = baudRate;
   switch (dataBits)
   {
      case SER_DATABITS_7:
         devCtrlBlock.ByteSize = 7;
      break;
      case SER_DATABITS_8:
         devCtrlBlock.ByteSize = 8;
      break;
      default:
          {
               config_file.write("Line3",5);
                return (SER_INVALID_PARAMETER);
          }
   }
   switch (stopBits)
   {
      case SER_STOPBITS_1:
         devCtrlBlock.StopBits = ONESTOPBIT;
      break;
      case SER_STOPBITS_2:
         devCtrlBlock.StopBits = TWOSTOPBITS;
      break;
      default:
          {
               config_file.write("Line4",5);
      return (SER_INVALID_PARAMETER);
          }
   }
   switch (parity)
   {
      case SER_PARITY_NONE:
         devCtrlBlock.fParity = FALSE;
         devCtrlBlock.Parity = NOPARITY;
      break;
      case SER_PARITY_EVEN:
         devCtrlBlock.fParity = TRUE;
         devCtrlBlock.Parity = EVENPARITY;
      break;
      case SER_PARITY_ODD:
         devCtrlBlock.fParity = TRUE;
         devCtrlBlock.Parity = ODDPARITY;
      break;
      default:
          {
               config_file.write("Line5",5);
      return (SER_INVALID_PARAMETER);
          }
   }
   switch (flowControl)
   {
      case SER_HANDSHAKE_RTS_CTS:
         devCtrlBlock.fOutX = FALSE; // Disable output X-ON/X-OFF
         devCtrlBlock.fInX = FALSE; // Disable input X-ON/X-OFF
         devCtrlBlock.fOutxCtsFlow = TRUE;
         devCtrlBlock.fOutxDsrFlow = FALSE;
         devCtrlBlock.fRtsControl = RTS_CONTROL_HANDSHAKE;
         devCtrlBlock.fDtrControl = DTR_CONTROL_ENABLE;
         devCtrlBlock.fDsrSensitivity = FALSE;
      break;
      case SER_HANDSHAKE_NONE:
         devCtrlBlock.fOutX = FALSE; // Disable output X-ON/X-OFF
         devCtrlBlock.fInX = FALSE; // Disable input X-ON/X-OFF
         devCtrlBlock.fOutxCtsFlow = FALSE;
         devCtrlBlock.fOutxDsrFlow = FALSE;
         devCtrlBlock.fRtsControl = RTS_CONTROL_TOGGLE;
         devCtrlBlock.fDtrControl = DTR_CONTROL_ENABLE;
         devCtrlBlock.fDsrSensitivity = FALSE;
      break;
      default:
          {
               config_file.write("Line6",5);
      return (SER_INVALID_PARAMETER);
          }
   }
   devCtrlBlock.fBinary = TRUE;
   devCtrlBlock.fErrorChar = FALSE;
   devCtrlBlock.fNull = FALSE;
   devCtrlBlock.fAbortOnError = FALSE;

   //
   // Store device control block
   //
   if (!SetCommState(port, &devCtrlBlock))
   {
        config_file.write("Line7",5);
      return (SER_INVALID_PARAMETER);
   }
   this->baudRate = baudRate;
   this->flowControl = flowControl;
config_file.write("Line8",5);

   return (SER_SUCCESS);
}

Answer 1

我看到你清除了RTS信号，我想这是用来启用RS485收发器的。 RS485 通常是半双工的，每次发送数据都需要开启/关闭传输。如果不这样做，则无法传输，或者始终处于传输状态，因此无法从同一线路上的其他设备接收任何数据。您可能需要切换此信号才能使通信正常进行。