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Diffstat (limited to 'ntpd/refclock_heath.c')
| -rw-r--r-- | ntpd/refclock_heath.c | 450 |
1 files changed, 450 insertions, 0 deletions
diff --git a/ntpd/refclock_heath.c b/ntpd/refclock_heath.c new file mode 100644 index 0000000..435d8f6 --- /dev/null +++ b/ntpd/refclock_heath.c @@ -0,0 +1,450 @@ +/* + * refclock_heath - clock driver for Heath GC-1000 + * (but no longer the GC-1001 Model II, which apparently never worked) + */ + +#ifdef HAVE_CONFIG_H +# include <config.h> +#endif + +#if defined(REFCLOCK) && defined(CLOCK_HEATH) + +#include "ntpd.h" +#include "ntp_io.h" +#include "ntp_refclock.h" +#include "ntp_stdlib.h" + +#include <stdio.h> +#include <ctype.h> + +#ifdef HAVE_SYS_IOCTL_H +# include <sys/ioctl.h> +#endif /* not HAVE_SYS_IOCTL_H */ + +/* + * This driver supports the Heath GC-1000 Most Accurate Clock, with + * RS232C Output Accessory. This is a WWV/WWVH receiver somewhat less + * robust than other supported receivers. Its claimed accuracy is 100 ms + * when actually synchronized to the broadcast signal, but this doesn't + * happen even most of the time, due to propagation conditions, ambient + * noise sources, etc. When not synchronized, the accuracy is at the + * whim of the internal clock oscillator, which can wander into the + * sunset without warning. Since the indicated precision is 100 ms, + * expect a host synchronized only to this thing to wander to and fro, + * occasionally being rudely stepped when the offset exceeds the default + * clock_max of 128 ms. + * + * There were two GC-1000 versions supported by this driver. The original + * GC-1000 with RS-232 output first appeared in 1983, but dissapeared + * from the market a few years later. The GC-1001 II with RS-232 output + * first appeared circa 1990, but apparently is no longer manufactured. + * The two models differ considerably, both in interface and commands. + * The GC-1000 has a pseudo-bipolar timecode output triggered by a RTS + * transition. The timecode includes both the day of year and time of + * day. The GC-1001 II has a true bipolar output and a complement of + * single character commands. The timecode includes only the time of + * day. + * + * The GC-1001 II was apparently never tested and, based on a Coverity + * scan, apparently never worked [Bug 689]. Related code has been disabled. + * + * GC-1000 + * + * The internal DIPswitches should be set to operate in MANUAL mode. The + * external DIPswitches should be set to GMT and 24-hour format. + * + * In MANUAL mode the clock responds to a rising edge of the request to + * send (RTS) modem control line by sending the timecode. Therefore, it + * is necessary that the operating system implement the TIOCMBIC and + * TIOCMBIS ioctl system calls and TIOCM_RTS control bit. Present + * restrictions require the use of a POSIX-compatible programming + * interface, although other interfaces may work as well. + * + * A simple hardware modification to the clock can be made which + * prevents the clock hearing the request to send (RTS) if the HI SPEC + * lamp is out. Route the HISPEC signal to the tone decoder board pin + * 19, from the display, pin 19. Isolate pin 19 of the decoder board + * first, but maintain connection with pin 10. Also isolate pin 38 of + * the CPU on the tone board, and use half an added 7400 to gate the + * original signal to pin 38 with that from pin 19. + * + * The clock message consists of 23 ASCII printing characters in the + * following format: + * + * hh:mm:ss.f AM dd/mm/yr<cr> + * + * hh:mm:ss.f = hours, minutes, seconds + * f = deciseconds ('?' when out of spec) + * AM/PM/bb = blank in 24-hour mode + * dd/mm/yr = day, month, year + * + * The alarm condition is indicated by '?', rather than a digit, at f. + * Note that 0?:??:??.? is displayed before synchronization is first + * established and hh:mm:ss.? once synchronization is established and + * then lost again for about a day. + * + * GC-1001 II + * + * Commands consist of a single letter and are case sensitive. When + * enterred in lower case, a description of the action performed is + * displayed. When enterred in upper case the action is performed. + * Following is a summary of descriptions as displayed by the clock: + * + * The clock responds with a command The 'A' command returns an ASCII + * local time string: HH:MM:SS.T xx<CR>, where + * + * HH = hours + * MM = minutes + * SS = seconds + * T = tenths-of-seconds + * xx = 'AM', 'PM', or ' ' + * <CR> = carriage return + * + * The 'D' command returns 24 pairs of bytes containing the variable + * divisor value at the end of each of the previous 24 hours. This + * allows the timebase trimming process to be observed. UTC hour 00 is + * always returned first. The first byte of each pair is the high byte + * of (variable divisor * 16); the second byte is the low byte of + * (variable divisor * 16). For example, the byte pair 3C 10 would be + * returned for a divisor of 03C1 hex (961 decimal). + * + * The 'I' command returns: | TH | TL | ER | DH | DL | U1 | I1 | I2 | , + * where + * + * TH = minutes since timebase last trimmed (high byte) + * TL = minutes since timebase last trimmed (low byte) + * ER = last accumulated error in 1.25 ms increments + * DH = high byte of (current variable divisor * 16) + * DL = low byte of (current variable divisor * 16) + * U1 = UT1 offset (/.1 s): | + | 4 | 2 | 1 | 0 | 0 | 0 | 0 | + * I1 = information byte 1: | W | C | D | I | U | T | Z | 1 | , + * where + * + * W = set by WWV(H) + * C = CAPTURE LED on + * D = TRIM DN LED on + * I = HI SPEC LED on + * U = TRIM UP LED on + * T = DST switch on + * Z = UTC switch on + * 1 = UT1 switch on + * + * I2 = information byte 2: | 8 | 8 | 4 | 2 | 1 | D | d | S | , + * where + * + * 8, 8, 4, 2, 1 = TIME ZONE switch settings + * D = DST bit (#55) in last-received frame + * d = DST bit (#2) in last-received frame + * S = clock is in simulation mode + * + * The 'P' command returns 24 bytes containing the number of frames + * received without error during UTC hours 00 through 23, providing an + * indication of hourly propagation. These bytes are updated each hour + * to reflect the previous 24 hour period. UTC hour 00 is always + * returned first. + * + * The 'T' command returns the UTC time: | HH | MM | SS | T0 | , where + * HH = tens-of-hours and hours (packed BCD) + * MM = tens-of-minutes and minutes (packed BCD) + * SS = tens-of-seconds and seconds (packed BCD) + * T = tenths-of-seconds (BCD) + * + * Fudge Factors + * + * A fudge time1 value of .04 s appears to center the clock offset + * residuals. The fudge time2 parameter is the local time offset east of + * Greenwich, which depends on DST. Sorry about that, but the clock + * gives no hint on what the DIPswitches say. + */ + +/* + * Interface definitions + */ +#define DEVICE "/dev/heath%d" /* device name and unit */ +#define PRECISION (-4) /* precision assumed (about 100 ms) */ +#define REFID "WWV\0" /* reference ID */ +#define DESCRIPTION "Heath GC-1000 Most Accurate Clock" /* WRU */ + +#define LENHEATH1 23 /* min timecode length */ +#if 0 /* BUG 689 */ +#define LENHEATH2 13 /* min timecode length */ +#endif + +/* + * Tables to compute the ddd of year form icky dd/mm timecode. Viva la + * leap. + */ +static int day1tab[] = {31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31}; +static int day2tab[] = {31, 29, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31}; + +/* + * Baud rate table. The GC-1000 supports 1200, 2400 and 4800; the + * GC-1001 II supports only 9600. + */ +static int speed[] = {B1200, B2400, B4800, B9600}; + +/* + * Function prototypes + */ +static int heath_start (int, struct peer *); +static void heath_shutdown (int, struct peer *); +static void heath_receive (struct recvbuf *); +static void heath_poll (int, struct peer *); + +/* + * Transfer vector + */ +struct refclock refclock_heath = { + heath_start, /* start up driver */ + heath_shutdown, /* shut down driver */ + heath_poll, /* transmit poll message */ + noentry, /* not used (old heath_control) */ + noentry, /* initialize driver */ + noentry, /* not used (old heath_buginfo) */ + NOFLAGS /* not used */ +}; + + +/* + * heath_start - open the devices and initialize data for processing + */ +static int +heath_start( + int unit, + struct peer *peer + ) +{ + struct refclockproc *pp; + int fd; + char device[20]; + + /* + * Open serial port + */ + snprintf(device, sizeof(device), DEVICE, unit); + fd = refclock_open(device, speed[peer->ttl & 0x3], + LDISC_REMOTE); + if (fd <= 0) + return (0); + pp = peer->procptr; + pp->io.clock_recv = heath_receive; + pp->io.srcclock = peer; + pp->io.datalen = 0; + pp->io.fd = fd; + if (!io_addclock(&pp->io)) { + close(fd); + pp->io.fd = -1; + return (0); + } + + /* + * Initialize miscellaneous variables + */ + peer->precision = PRECISION; + pp->clockdesc = DESCRIPTION; + memcpy(&pp->refid, REFID, 4); + return (1); +} + + +/* + * heath_shutdown - shut down the clock + */ +static void +heath_shutdown( + int unit, + struct peer *peer + ) +{ + struct refclockproc *pp; + + pp = peer->procptr; + if (-1 != pp->io.fd) + io_closeclock(&pp->io); +} + + +/* + * heath_receive - receive data from the serial interface + */ +static void +heath_receive( + struct recvbuf *rbufp + ) +{ + struct refclockproc *pp; + struct peer *peer; + l_fp trtmp; + int month, day; + int i; + char dsec, a[5]; + + /* + * Initialize pointers and read the timecode and timestamp + */ + peer = rbufp->recv_peer; + pp = peer->procptr; + pp->lencode = refclock_gtlin(rbufp, pp->a_lastcode, BMAX, + &trtmp); + + /* + * We get down to business, check the timecode format and decode + * its contents. If the timecode has invalid length or is not in + * proper format, we declare bad format and exit. + */ + switch (pp->lencode) { + + /* + * GC-1000 timecode format: "hh:mm:ss.f AM mm/dd/yy" + * GC-1001 II timecode format: "hh:mm:ss.f " + */ + case LENHEATH1: + if (sscanf(pp->a_lastcode, + "%2d:%2d:%2d.%c%5c%2d/%2d/%2d", &pp->hour, + &pp->minute, &pp->second, &dsec, a, &month, &day, + &pp->year) != 8) { + refclock_report(peer, CEVNT_BADREPLY); + return; + } + break; + +#if 0 /* BUG 689 */ + /* + * GC-1001 II timecode format: "hh:mm:ss.f " + */ + case LENHEATH2: + if (sscanf(pp->a_lastcode, "%2d:%2d:%2d.%c", &pp->hour, + &pp->minute, &pp->second, &dsec) != 4) { + refclock_report(peer, CEVNT_BADREPLY); + return; + } else { + struct tm *tm_time_p; + time_t now; + + time(&now); /* we should grab 'now' earlier */ + tm_time_p = gmtime(&now); + /* + * There is a window of time around midnight + * where this will Do The Wrong Thing. + */ + if (tm_time_p) { + month = tm_time_p->tm_mon + 1; + day = tm_time_p->tm_mday; + } else { + refclock_report(peer, CEVNT_FAULT); + return; + } + } + break; +#endif + + default: + refclock_report(peer, CEVNT_BADREPLY); + return; + } + + /* + * We determine the day of the year from the DIPswitches. This + * should be fixed, since somebody might forget to set them. + * Someday this hazard will be fixed by a fiendish scheme that + * looks at the timecode and year the radio shows, then computes + * the residue of the seconds mod the seconds in a leap cycle. + * If in the third year of that cycle and the third and later + * months of that year, add one to the day. Then, correct the + * timecode accordingly. Icky pooh. This bit of nonsense could + * be avoided if the engineers had been required to write a + * device driver before finalizing the timecode format. + */ + if (month < 1 || month > 12 || day < 1) { + refclock_report(peer, CEVNT_BADTIME); + return; + } + if (pp->year % 4) { + if (day > day1tab[month - 1]) { + refclock_report(peer, CEVNT_BADTIME); + return; + } + for (i = 0; i < month - 1; i++) + day += day1tab[i]; + } else { + if (day > day2tab[month - 1]) { + refclock_report(peer, CEVNT_BADTIME); + return; + } + for (i = 0; i < month - 1; i++) + day += day2tab[i]; + } + pp->day = day; + + /* + * Determine synchronization and last update + */ + if (!isdigit((int)dsec)) + pp->leap = LEAP_NOTINSYNC; + else { + pp->nsec = (dsec - '0') * 100000000; + pp->leap = LEAP_NOWARNING; + } + if (!refclock_process(pp)) + refclock_report(peer, CEVNT_BADTIME); +} + + +/* + * heath_poll - called by the transmit procedure + */ +static void +heath_poll( + int unit, + struct peer *peer + ) +{ + struct refclockproc *pp; + int bits = TIOCM_RTS; + + /* + * At each poll we check for timeout and toggle the RTS modem + * control line, then take a timestamp. Presumably, this is the + * event the radio captures to generate the timecode. + * Apparently, the radio takes about a second to make up its + * mind to send a timecode, so the receive timestamp is + * worthless. + */ + pp = peer->procptr; + + /* + * We toggle the RTS modem control lead (GC-1000) and sent a T + * (GC-1001 II) to kick a timecode loose from the radio. This + * code works only for POSIX and SYSV interfaces. With bsd you + * are on your own. We take a timestamp between the up and down + * edges to lengthen the pulse, which should be about 50 usec on + * a Sun IPC. With hotshot CPUs, the pulse might get too short. + * Later. + * + * Bug 689: Even though we no longer support the GC-1001 II, + * I'm leaving the 'T' write in for timing purposes. + */ + if (ioctl(pp->io.fd, TIOCMBIC, (char *)&bits) < 0) + refclock_report(peer, CEVNT_FAULT); + get_systime(&pp->lastrec); + if (write(pp->io.fd, "T", 1) != 1) + refclock_report(peer, CEVNT_FAULT); + ioctl(pp->io.fd, TIOCMBIS, (char *)&bits); + if (pp->coderecv == pp->codeproc) { + refclock_report(peer, CEVNT_TIMEOUT); + return; + } + pp->lastref = pp->lastrec; + refclock_receive(peer); + record_clock_stats(&peer->srcadr, pp->a_lastcode); +#ifdef DEBUG + if (debug) + printf("heath: timecode %d %s\n", pp->lencode, + pp->a_lastcode); +#endif + pp->polls++; +} + +#else +int refclock_heath_bs; +#endif /* REFCLOCK */ |