串口通信 同步方式 怎么设置readfile超时处理

COMMTIMEOUTS m_CommTimeouts5; 

    // Config timeouts 
    m_CommTimeouts5.ReadIntervalTimeout = MAXDWORD; 
    m_CommTimeouts5.ReadTotalTimeoutConstant = MAXDWORD; 
    m_CommTimeouts5.ReadTotalTimeoutMultiplier = MAXDWORD; 
    m_CommTimeouts5.WriteTotalTimeoutConstant = MAXDWORD; 
    m_CommTimeouts5.WriteTotalTimeoutMultiplier = MAXDWORD; 
    SetCommTimeouts(g_hPWMCom, &m_CommTimeouts5);