/* * tg.c generate WWV or IRIG signals for test */ /* * This program can generate audio signals that simulate the WWV/H * broadcast timecode. Alternatively, it can generate the IRIG-B * timecode commonly used to synchronize laboratory equipment. It is * intended to test the WWV/H driver (refclock_wwv.c) and the IRIG * driver (refclock_irig.c) in the NTP driver collection. * * Besides testing the drivers themselves, this program can be used to * synchronize remote machines over audio transmission lines or program * feeds. The program reads the time on the local machine and sets the * initial epoch of the signal generator within one millisecond. * Alernatively, the initial epoch can be set to an arbitrary time. This * is useful when searching for bugs and testing for correct response to * a leap second in UTC. Note however, the ultimate accuracy is limited * by the intrinsic frequency error of the codec sample clock, which can # reach well over 100 PPM. * * The default is to route generated signals to the line output * jack; the s option on the command line routes these signals to the * internal speaker as well. The v option controls the speaker volume * over the range 0-255. The signal generator by default uses WWV * format; the h option switches to WWVH format and the i option * switches to IRIG-B format. * * Once started the program runs continuously. The default initial epoch * for the signal generator is read from the computer system clock when * the program starts. The y option specifies an alternate epoch using a * string yydddhhmmss, where yy is the year of century, ddd the day of * year, hh the hour of day and mm the minute of hour. For instance, * 1946Z on 1 January 2006 is 060011946. The l option lights the leap * warning bit in the WWV/H timecode, so is handy to check for correct * behavior at the next leap second epoch. The remaining options are * specified below under the Parse Options heading. Most of these are * for testing. * * During operation the program displays the WWV/H timecode (9 digits) * or IRIG timecode (20 digits) as each new string is constructed. The * display is followed by the BCD binary bits as transmitted. Note that * the transmissionorder is low-order first as the frame is processed * left to right. For WWV/H The leap warning L preceeds the first bit. * For IRIG the on-time marker M preceeds the first (units) bit, so its * code is delayed one bit and the next digit (tens) needs only three * bits. * * The program has been tested with the Sun Blade 1500 running Solaris * 10, but not yet with other machines. It uses no special features and * should be readily portable to other hardware and operating systems. */ #include <stdio.h> #include <stdlib.h> #include <time.h> #include <sys/audio.h> #include <math.h> #include <errno.h> #include <sys/types.h> #include <sys/stat.h> #include <fcntl.h> #include <string.h> #include <unistd.h> #define SECOND 8000 /* one second of 125-us samples */ #define BUFLNG 400 /* buffer size */ #define DEVICE "/dev/audio" /* default audio device */ #define WWV 0 /* WWV encoder */ #define IRIG 1 /* IRIG-B encoder */ #define OFF 0 /* zero amplitude */ #define LOW 1 /* low amplitude */ #define HIGH 2 /* high amplitude */ #define DATA0 200 /* WWV/H 0 pulse */ #define DATA1 500 /* WWV/H 1 pulse */ #define PI 800 /* WWV/H PI pulse */ #define M2 2 /* IRIG 0 pulse */ #define M5 5 /* IRIG 1 pulse */ #define M8 8 /* IRIG PI pulse */ /* * Companded sine table amplitude 3000 units */ int c3000[] = {1, 48, 63, 70, 78, 82, 85, 89, 92, 94, /* 0-9 */ 96, 98, 99, 100, 101, 101, 102, 103, 103, 103, /* 10-19 */ 103, 103, 103, 103, 102, 101, 101, 100, 99, 98, /* 20-29 */ 96, 94, 92, 89, 85, 82, 78, 70, 63, 48, /* 30-39 */ 129, 176, 191, 198, 206, 210, 213, 217, 220, 222, /* 40-49 */ 224, 226, 227, 228, 229, 229, 230, 231, 231, 231, /* 50-59 */ 231, 231, 231, 231, 230, 229, 229, 228, 227, 226, /* 60-69 */ 224, 222, 220, 217, 213, 210, 206, 198, 191, 176}; /* 70-79 */ /* * Companded sine table amplitude 6000 units */ int c6000[] = {1, 63, 78, 86, 93, 98, 101, 104, 107, 110, /* 0-9 */ 112, 113, 115, 116, 117, 117, 118, 118, 119, 119, /* 10-19 */ 119, 119, 119, 118, 118, 117, 117, 116, 115, 113, /* 20-29 */ 112, 110, 107, 104, 101, 98, 93, 86, 78, 63, /* 30-39 */ 129, 191, 206, 214, 221, 226, 229, 232, 235, 238, /* 40-49 */ 240, 241, 243, 244, 245, 245, 246, 246, 247, 247, /* 50-59 */ 247, 247, 247, 246, 246, 245, 245, 244, 243, 241, /* 60-69 */ 240, 238, 235, 232, 229, 226, 221, 214, 206, 191}; /* 70-79 */ /* * Decoder operations at the end of each second are driven by a state * machine. The transition matrix consists of a dispatch table indexed * by second number. Each entry in the table contains a case switch * number and argument. */ struct progx { int sw; /* case switch number */ int arg; /* argument */ }; /* * Case switch numbers */ #define DATA 0 /* send data (0, 1, PI) */ #define COEF 1 /* send BCD bit */ #define DEC 2 /* decrement to next digit */ #define MIN 3 /* minute pulse */ #define LEAP 4 /* leap warning */ #define DUT1 5 /* DUT1 bits */ #define DST1 6 /* DST1 bit */ #define DST2 7 /* DST2 bit */ /* * WWV/H format (100-Hz, 9 digits, 1 m frame) */ struct progx progx[] = { {MIN, 800}, /* 0 minute sync pulse */ {DATA, DATA0}, /* 1 */ {DST2, 0}, /* 2 DST2 */ {LEAP, 0}, /* 3 leap warning */ {COEF, 1}, /* 4 1 year units */ {COEF, 2}, /* 5 2 */ {COEF, 4}, /* 6 4 */ {COEF, 8}, /* 7 8 */ {DEC, DATA0}, /* 8 */ {DATA, PI}, /* 9 p1 */ {COEF, 1}, /* 10 1 minute units */ {COEF, 2}, /* 11 2 */ {COEF, 4}, /* 12 4 */ {COEF, 8}, /* 13 8 */ {DEC, DATA0}, /* 14 */ {COEF, 1}, /* 15 10 minute tens */ {COEF, 2}, /* 16 20 */ {COEF, 4}, /* 17 40 */ {COEF, 8}, /* 18 80 (not used) */ {DEC, PI}, /* 19 p2 */ {COEF, 1}, /* 20 1 hour units */ {COEF, 2}, /* 21 2 */ {COEF, 4}, /* 22 4 */ {COEF, 8}, /* 23 8 */ {DEC, DATA0}, /* 24 */ {COEF, 1}, /* 25 10 hour tens */ {COEF, 2}, /* 26 20 */ {COEF, 4}, /* 27 40 (not used) */ {COEF, 8}, /* 28 80 (not used) */ {DEC, PI}, /* 29 p3 */ {COEF, 1}, /* 30 1 day units */ {COEF, 2}, /* 31 2 */ {COEF, 4}, /* 32 4 */ {COEF, 8}, /* 33 8 */ {DEC, DATA0}, /* 34 not used */ {COEF, 1}, /* 35 10 day tens */ {COEF, 2}, /* 36 20 */ {COEF, 4}, /* 37 40 */ {COEF, 8}, /* 38 80 */ {DEC, PI}, /* 39 p4 */ {COEF, 1}, /* 40 100 day hundreds */ {COEF, 2}, /* 41 200 */ {COEF, 4}, /* 42 400 (not used) */ {COEF, 8}, /* 43 800 (not used) */ {DEC, DATA0}, /* 44 */ {DATA, DATA0}, /* 45 */ {DATA, DATA0}, /* 46 */ {DATA, DATA0}, /* 47 */ {DATA, DATA0}, /* 48 */ {DATA, PI}, /* 49 p5 */ {DUT1, 8}, /* 50 DUT1 sign */ {COEF, 1}, /* 51 10 year tens */ {COEF, 2}, /* 52 20 */ {COEF, 4}, /* 53 40 */ {COEF, 8}, /* 54 80 */ {DST1, 0}, /* 55 DST1 */ {DUT1, 1}, /* 56 0.1 DUT1 fraction */ {DUT1, 2}, /* 57 0.2 */ {DUT1, 4}, /* 58 0.4 */ {DATA, PI}, /* 59 p6 */ {DATA, DATA0}, /* 60 leap */ }; /* * IRIG format except first frame (1000 Hz, 20 digits, 1 s frame) */ struct progx progy[] = { {COEF, 1}, /* 0 1 units */ {COEF, 2}, /* 1 2 */ {COEF, 4}, /* 2 4 */ {COEF, 8}, /* 3 8 */ {DEC, M2}, /* 4 im */ {COEF, 1}, /* 5 10 tens */ {COEF, 2}, /* 6 20 */ {COEF, 4}, /* 7 40 */ {COEF, 8}, /* 8 80 */ {DEC, M8}, /* 9 pi */ }; /* * IRIG format first frame (1000 Hz, 20 digits, 1 s frame) */ struct progx progz[] = { {MIN, M8}, /* 0 pi (second) */ {COEF, 1}, /* 1 1 units */ {COEF, 2}, /* 2 2 */ {COEF, 4}, /* 3 4 */ {COEF, 8}, /* 4 8 */ {DEC, M2}, /* 5 im */ {COEF, 1}, /* 6 10 tens */ {COEF, 2}, /* 7 20 */ {COEF, 4}, /* 8 40 */ {DEC, M8}, /* 9 pi */ }; /* * Forward declarations */ void sec(int); /* send second */ void digit(int); /* encode digit */ void peep(int, int, int); /* send cycles */ void delay(int); /* delay samples */ /* * Global variables */ char buffer[BUFLNG]; /* output buffer */ int bufcnt = 0; /* buffer counter */ int second = 0; /* seconds counter */ int fd; /* audio codec file descriptor */ int tone = 1000; /* WWV sync frequency */ int level = AUDIO_MAX_GAIN / 8; /* output level */ int port = AUDIO_LINE_OUT; /* output port */ int encode = WWV; /* encoder select */ int leap = 0; /* leap indicator */ int dst = 0; /* winter/summer time */ int dut1 = 0; /* DUT1 correction (sign, magnitude) */ int utc = 0; /* option epoch */ /* * Main program */ int main( int argc, /* command line options */ char **argv /* poiniter to list of tokens */ ) { struct timeval tv; /* system clock at startup */ audio_info_t info; /* Sun audio structure */ struct tm *tm = NULL; /* structure returned by gmtime */ char device[50]; /* audio device */ char code[100]; /* timecode */ int rval, temp, arg, sw, ptr; int minute, hour, day, year; int i; /* * Parse options */ strcpy(device, DEVICE); year = 0; while ((temp = getopt(argc, argv, "a:dhilsu:v:y:")) != -1) { switch (temp) { case 'a': /* specify audio device (/dev/audio) */ strcpy(device, optarg); break; case 'd': /* set DST for summer (WWV/H only) */ dst++; break; case 'h': /* select WWVH sync frequency */ tone = 1200; break; case 'i': /* select irig format */ encode = IRIG; break; case 'l': /* set leap warning bit (WWV/H only) */ leap++; break; case 's': /* enable speaker */ port |= AUDIO_SPEAKER; break; case 'u': /* set DUT1 offset (-7 to +7) */ sscanf(optarg, "%d", &dut1); if (dut1 < 0) dut1 = abs(dut1); else dut1 |= 0x8; break; case 'v': /* set output level (0-255) */ sscanf(optarg, "%d", &level); break; case 'y': /* set initial date and time */ sscanf(optarg, "%2d%3d%2d%2d", &year, &day, &hour, &minute); utc++; break; defult: printf("invalid option %c\n", temp); break; } } /* * Open audio device and set options */ fd = open("/dev/audio", O_WRONLY); if (fd <= 0) { printf("audio open %s\n", strerror(errno)); exit(1); } rval = ioctl(fd, AUDIO_GETINFO, &info); if (rval < 0) { printf("audio control %s\n", strerror(errno)); exit(0); } info.play.port = port; info.play.gain = level; info.play.sample_rate = SECOND; info.play.channels = 1; info.play.precision = 8; info.play.encoding = AUDIO_ENCODING_ULAW; printf("port %d gain %d rate %d chan %d prec %d encode %d\n", info.play.port, info.play.gain, info.play.sample_rate, info.play.channels, info.play.precision, info.play.encoding); ioctl(fd, AUDIO_SETINFO, &info); /* * Unless specified otherwise, read the system clock and * initialize the time. */ if (!utc) { gettimeofday(&tv, NULL); tm = gmtime(&tv.tv_sec); minute = tm->tm_min; hour = tm->tm_hour; day = tm->tm_yday + 1; year = tm->tm_year % 100; second = tm->tm_sec; /* * Delay the first second so the generator is accurately * aligned with the system clock within one sample (125 * microseconds ). */ delay(SECOND - tv.tv_usec * 8 / 1000); } memset(code, 0, sizeof(code)); switch (encode) { /* * For WWV/H and default time, carefully set the signal * generator seconds number to agree with the current time. */ case WWV: printf("year %d day %d time %02d:%02d:%02d tone %d\n", year, day, hour, minute, second, tone); sprintf(code, "%01d%03d%02d%02d%01d", year / 10, day, hour, minute, year % 10); printf("%s\n", code); ptr = 8; for (i = 0; i <= second; i++) { if (progx[i].sw == DEC) ptr--; } break; /* * For IRIG the signal generator runs every second, so requires * no additional alignment. */ case IRIG: printf("sbs %x year %d day %d time %02d:%02d:%02d\n", 0, year, day, hour, minute, second); break; } /* * Run the signal generator to generate new timecode strings * once per minute for WWV/H and once per second for IRIG. */ while(1) { /* * Crank the state machine to propagate carries to the * year of century. Note that we delayed up to one * second for alignment after reading the time, so this * is the next second. */ second = (second + 1) % 60; if (second == 0) { minute++; if (minute >= 60) { minute = 0; hour++; } if (hour >= 24) { hour = 0; day++; } /* * At year rollover check for leap second. */ if (day >= (year & 0x3 ? 366 : 367)) { if (leap) { sec(DATA0); printf("\nleap!"); leap = 0; } day = 1; year++; } if (encode == WWV) { sprintf(code, "%01d%03d%02d%02d%01d", year / 10, day, hour, minute, year % 10); printf("\n%s\n", code); ptr = 8; } } if (encode == IRIG) { sprintf(code, "%04x%04d%06d%02d%02d%02d", 0, year, day, hour, minute, second); printf("%s\n", code); ptr = 19; } /* * Generate data for the second */ switch(encode) { /* * The IRIG second consists of 20 BCD digits of width- * modulateod pulses at 2, 5 and 8 ms and modulated 50 * percent on the 1000-Hz carrier. */ case IRIG: for (i = 0; i < 100; i++) { if (i < 10) { sw = progz[i].sw; arg = progz[i].arg; } else { sw = progy[i % 10].sw; arg = progy[i % 10].arg; } switch(sw) { case COEF: /* send BCD bit */ if (code[ptr] & arg) { peep(M5, 1000, HIGH); peep(M5, 1000, LOW); printf("1"); } else { peep(M2, 1000, HIGH); peep(M8, 1000, LOW); printf("0"); } break; case DEC: /* send IM/PI bit */ ptr--; printf(" "); peep(arg, 1000, HIGH); peep(10 - arg, 1000, LOW); break; case MIN: /* send data bit */ peep(arg, 1000, HIGH); peep(10 - arg, 1000, LOW); printf("M "); break; } if (ptr < 0) break; } printf("\n"); break; /* * The WWV/H second consists of 9 BCD digits of width- * modulateod pulses 200, 500 and 800 ms at 100-Hz. */ case WWV: sw = progx[second].sw; arg = progx[second].arg; switch(sw) { case DATA: /* send data bit */ sec(arg); break; case COEF: /* send BCD bit */ if (code[ptr] & arg) { sec(DATA1); printf("1"); } else { sec(DATA0); printf("0"); } break; case LEAP: /* send leap bit */ if (leap) { sec(DATA1); printf("L "); } else { sec(DATA0); printf(" "); } break; case DEC: /* send data bit */ ptr--; sec(arg); printf(" "); break; case MIN: /* send minute sync */ peep(arg, tone, HIGH); peep(1000 - arg, tone, OFF); break; case DUT1: /* send DUT1 bits */ if (dut1 & arg) sec(DATA1); else sec(DATA0); break; case DST1: /* send DST1 bit */ ptr--; if (dst) sec(DATA1); else sec(DATA0); printf(" "); break; case DST2: /* send DST2 bit */ if (dst) sec(DATA1); else sec(DATA0); break; } } } } /* * Generate WWV/H 0 or 1 data pulse. */ void sec( int code /* DATA0, DATA1, PI */ ) { /* * The WWV data pulse begins with 5 ms of 1000 Hz follwed by a * guard time of 25 ms. The data pulse is 170, 570 or 770 ms at * 100 Hz corresponding to 0, 1 or position indicator (PI), * respectively. Note the 100-Hz data pulses are transmitted 6 * dB below the 1000-Hz sync pulses. Originally the data pulses * were transmited 10 dB below the sync pulses, but the station * engineers increased that to 6 dB because the Heath GC-1000 * WWV/H radio clock worked much better. */ peep(5, tone, HIGH); /* send seconds tick */ peep(25, tone, OFF); peep(code - 30, 100, LOW); /* send data */ peep(1000 - code, 100, OFF); } /* * Generate cycles of 100 Hz or any multiple of 100 Hz. */ void peep( int pulse, /* pulse length (ms) */ int freq, /* frequency (Hz) */ int amp /* amplitude */ ) { int increm; /* phase increment */ int i, j; if (amp == OFF || freq == 0) increm = 10; else increm = freq / 100; j = 0; for (i = 0 ; i < pulse * 8; i++) { switch (amp) { case HIGH: buffer[bufcnt++] = ~c6000[j]; break; case LOW: buffer[bufcnt++] = ~c3000[j]; break; default: buffer[bufcnt++] = ~0; } if (bufcnt >= BUFLNG) { write(fd, buffer, BUFLNG); bufcnt = 0; } j = (j + increm) % 80; } } /* * Delay for initial phasing */ void delay ( int delay /* delay in samples */ ) { int samples; /* samples remaining */ samples = delay; memset(buffer, 0, BUFLNG); while (samples >= BUFLNG) { write(fd, buffer, BUFLNG); samples -= BUFLNG; } write(fd, buffer, samples); }