tbit.sync.h

一个通讯程序源码

/*+-------------------------------------------------------------------------
	sync_Telebit() - sync modem with our DTE speed
--------------------------------------------------------------------------*/
/*+:EDITS:*/
/*:09-10-1992-13:59-wht@n4hgf-ECU release 3.20 */
/*:08-22-1992-15:38-wht@n4hgf-ECU release 3.20 BETA */
/*:03-30-1992-14:18-root@n4hgf-add lbreak before wakeup */
void
sync_Telebit()
{
	register int maxretry = 4;
	register int count;
	unsigned char rdchar;
	long pace_msec_save = DCE_write_pace_msec;

	while(--maxretry)
	{
		lbreak();
		Nap(200L);
		DCE_write_pace_msec = 50;
		lwrite("aaaaaate1\r");
		DCE_write_pace_msec = pace_msec_save;
		Nap(200L);
		lflush();
		count = 5;
		while(count)	/* wait 120-200 msec for character, depending on HZ */
		{
			write(dce_fd,"a",1);
			ioctl(dce_fd,TCSETAW,&dce_termio);	/* wait for I/O to drain */
			Nap(120L);	/* must handle 110 baud */
			if(rdchk(dce_fd))
				break;
			count--;
		}
		rdchar = 0;
		if(count && (read(dce_fd,&rdchar,1) == 1) && ((rdchar & 0x7F) == 'a'))
		{
			Nap(120L);
			lflush();
			return;
		}
		DEBUG(2,"Telebit SYNC failed ... retrying (%02x)\n",rdchar);
		lflash_DTR();
	}

	DEBUG(1,"Telebit SYNC FAILED\n",0);
	myexit(RC_FAIL | RCE_TIMOUT);

}	/* end of sync_Telebit */