--- /dev/null
+/*
+ * 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 <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);
+}
projects / thirdparty / ntp.git / commitdiff
