基于select的Linux串口485读写，文件描述符 fd_set

/*********************************************************************** * $Id$ * Project: Power System Monitor * File: * Description: * * @version: V1.0 * @date: 26th March 2012 * *----------------------------------------------------------------- * * Revise: * date version author description * * * * **********************************************************************/ #include <sys/types.h> #include <unistd.h> #include <fcntl.h> #include <sys/ioctl.h> #include <stdio.h> #include <unistd.h> #include <termios.h> #include "./typedef.h" #include "./rs485.h" /********************************************************************************************************* * Function name: port_speed * Descriptions: * input parameters: * output parameters: * Returned value: *********************************************************************************************************/ uint16_t port_speed(int fd, int speed) { const int speed_arr[] = {B115200, B57600, B38400, B19200, B9600, B4800, B2400, B1200, B300,}; const int name_arr[] = {115200, 57600, 38400, 19200, 9600, 4800, 2400, 1200, 300,}; int i; int status; struct termios Opt; DEBUGMSG(0, ("%s ... %d\n", __FUNCTION__, speed)); tcgetattr(fd, &Opt); for( i= 0; i < sizeof(speed_arr)/sizeof(int); i++) { if(speed == name_arr[i]) { tcflush(fd, TCIOFLUSH); cfsetispeed(&Opt, speed_arr[i]); cfsetospeed(&Opt, speed_arr[i]); status = tcsetattr(fd, TCSANOW, &Opt); if(status != 0) { perror("tcsetattr fd1"); } return TRUE; } tcflush(fd, TCIOFLUSH); } return FALSE; } /********************************************************************************************************* * Function name: port_set * Descriptions: * input parameters: * output parameters: * Returned value: *********************************************************************************************************/ int port_set(int fd, int databits, int stopbits, int parity) { DEBUGMSG(0,(" fd:%d...stopbits:%d ...parity:%c....\n", fd, stopbits, parity)); struct termios options; if(tcgetattr(fd, &options) != 0) { perror("SetupSerial 1"); return FALSE; } options.c_cflag &= ~CSIZE; switch (databits) { /*设置数据位数*/ case 7: options.c_cflag |= CS7; break; case 8: options.c_cflag |= CS8; break; default: fprintf(stderr,"Unsupported data size\n"); return FALSE; } switch (parity) { case 'n': case 'N': options.c_cflag &= ~PARENB; /* Clear parity enable */ options.c_iflag &= ~INPCK; /* Clear parity checking */ break; case 'o': case 'O': options.c_cflag |= (PARODD | PARENB); /* 设置为奇效验*/ options.c_iflag |= INPCK; /* enable parity checking */ break; case 'e': case 'E': options.c_cflag |= PARENB; /* Enable parity */ options.c_cflag &= ~PARODD; /* 转换为偶效验*/ options.c_iflag |= INPCK; /* enable parity checking */ break; case 'S': case 's': /*as no parity*/ options.c_cflag &= ~PARENB; options.c_cflag &= ~CSTOPB; break; default: fprintf(stderr,"Unsupported parity\n"); return FALSE; } switch (stopbits) { /* 设置停止位*/ case 1: options.c_cflag &= ~CSTOPB; break; case 2: options.c_cflag |= CSTOPB; break; default: fprintf(stderr,"Unsupported stop bits\n"); return FALSE; } /* Set input parity option */ /*have set it befor*/ // if (parity != 'n') // options.c_iflag |= INPCK; options.c_iflag = 0; /*直接设置为0最方便；否则以前的设置会影响接收*/ options.c_cflag |= (CLOCAL | CREAD); options.c_lflag &= ~(ICANON | ECHO | ECHOE | ISIG); options.c_oflag &= ~OPOST; /*Output*/ tcflush(fd, TCIFLUSH); /* unit : 100ms or 1/10秒 设置超时 50 = 5 seconds; 2 = 200ms*/ options.c_cc[VTIME] = 1; options.c_cc[VMIN] = 0; /* Update the options and do it NOW */ if (tcsetattr(fd, TCSANOW, &options) != 0) { perror(" SetupSerial err"); return FALSE; } return TRUE; } /********************************************************************************************************* ** Function name: WhichisReadable ** Descriptions: find which fd can be read ** input parameters: *fd : 串口描述符指针 ** nmsTimeOut : milliseconds ** output parameters: ** Returned value: 1 : data ready ** 0 : timeout ** -1 : wait error *********************************************************************************************************/ int CommListen(int *fds,fd_set *readfds,fd_set *writefds,fd_set *errfds,int num,int time) { int maxfd,i,rnt; struct timeval tv; tv.tv_usec = time*1000; // usec tv.tv_sec = 0; // seconds if(num <= 0) return -1; for(i = 0;i < num - 1; i++) maxfd =(*(fds + i + 1)> *(fds + i))? *(fds +i+1) : *(fds + i); FD_ZERO(readfds); FD_ZERO(writefds); FD_ZERO(errfds); for(i = 0;i<num;i++){ FD_SET(*(fds + i),readfds); FD_SET(*(fds + i),writefds); FD_SET(*(fds + i),errfds); } rnt = select(maxfd+1,readfds,writefds,errfds,&tv); return rnt; } /********************************************************************************************************* * Function name: Rs485dir * Descriptions: * input parameters: * output parameters: * Returned value: *********************************************************************************************************/ void Rs485dir(int fdcom, uint16_t bOut) { int i; int ret1, ret2, iostatus; iostatus = 0; DEBUGMSG(0, ("%s ...\n", __FUNCTION__)); if(bOut) { for(i = 0; i < 10; i++) { ret1 = ioctl(fdcom, TIOCMGET, &iostatus); if(0 != ret1) { //return FAILURE; /*wait 2ms */ usleep(2000); continue; } else break; } for(i = 0 ; i < 10 ; i++) { iostatus &= ~(TIOCM_RTS | TIOCM_DTR); ret2 = ioctl(fdcom, TIOCMSET, &iostatus); if(ret2 == 0) break; } } else { for(i = 0 ; i < 10; i++) { ret1 = ioctl(fdcom, TIOCMGET, &iostatus); if(0 != ret1) { usleep(2000); continue; } else break; } for(i = 0 ; i < 10 ; i++) { iostatus = (TIOCM_RTS | TIOCM_DTR); ret2 = ioctl(fdcom, TIOCMSET, &iostatus); if(ret2 == 0) break; } } return; } /********************************************************************************************************* ** Function name: WaitFiledReadable ** Descriptions: serial port receive data ** input parameters: fd : 串口描述符 ** nmsTimeOut : milliseconds ** output parameters: ** Returned value: 1 : data ready ** 0 : timeout ** -1 : wait error *********************************************************************************************************/ #define WAIT_DATA_TIMEOUT 0 #define SELECT_MAX_WAIT_INTERVAL 2 // 2s #define NMSRXTXTIMEOUT 200 //100 int WaitFiledReadable(int fd, int nmsTimeOut) { int iRnt; fd_set fdset, fderr; struct timeval tv; if (nmsTimeOut < (SELECT_MAX_WAIT_INTERVAL*1000)) { tv.tv_usec = nmsTimeOut%1000*1000; /* usec */ tv.tv_sec = nmsTimeOut/1000; /* seconds */ } else { tv.tv_usec = 0; /* usec */ tv.tv_sec = SELECT_MAX_WAIT_INTERVAL; /* seconds */ } FD_ZERO(&fdset); /* Initializes the set to the NULL set. */ FD_SET(fd, &fdset); /* Adds descriptor s to set. */ fderr = fdset; /* determines the status of on