* 99/11/29 j.c.lang added fudge flag 1 to control
* clock polling
* 99/12/15 j.c.lang fixed 320 quality flag
+ * 01/02/21 s.l.smith fixed 33x quality flag
+ * added more debugging stuff
+ * updated 33x time code explanation
*
* Questions, bugs, ideas send to:
* Joseph C. Lang
#define REFID "WWVB" /* reference ID */
#define DESCRIPTION "Ultralink WWVB Receiver" /* WRU */
-#define LEN33X 32 /* timecode length Model 33X */
+#define LEN33X 32 /* timecode length Model 325 & 33X */
#define LEN320 24 /* timecode length Model 320 */
/*
char syncchar; /* synchronization indicator */
char leapchar; /* leap indicator */
char modechar; /* model 320 mode flag */
+ char char_quality[2]; /* temp quality flag */
/*
* Initialize pointers and read the timecode and timestamp
case LEN33X:
/*
* Model 33X decoder:
- * Timecode format is:
- * <CR><LF>S9+D 00 YYYY+DDDUTCS HH:MM:SSl+5
- * S sync indicator S insync N not in sync
- * the sync flag is WWVB decoder sync
- * nothing to do with time being correct
- * 9+ signal level 0-9 9+ if over 9 note single digit
- * followed by space
- * D data bit ( fun to watch but useless ;-)
- * space
- * 00 hours since last GOOD WWVB frame sync
- * space
- * YYYY current year
- * + leap year indicator
- * DDD day of year
- * UTC timezone (always UTC)
- * S daylight savings indicator
- * space
- * HH hours
+ * Timecode format from January 29, 2001 datasheet is:
+ * <CR><LF>S9+D 00 YYYY+DDDUTCS HH:MM:SSL+5
+ * S WWVB decoder sync indicator. S for in-sync(?)
+ * or N for noisy signal.
+ * 9+ RF signal level in S-units, 0-9 followed by
+ * a space (0x20). The space turns to '+' if the
+ * level is over 9.
+ * D Data bit 0, 1, 2 (position mark), or
+ * 3 (unknown).
+ * space Space character (0x20)
+ * 00 Hours since last good WWVB frame sync. Will
+ * be 00-23 hrs, or '1d' to '7d'. Will be 'Lk'
+ * if currently in sync.
+ * space Space character (0x20)
+ * YYYY Current year, 1990-2089
+ * + Leap year indicator. '+' if a leap year,
+ * a space (0x20) if not.
+ * DDD Day of year, 001 - 366.
+ * UTC Timezone (always 'UTC').
+ * S Daylight savings indicator
+ * S - standard time (STD) in effect
+ * O - during STD to DST day 0000-2400
+ * D - daylight savings time (DST) in effect
+ * I - during DST to STD day 0000-2400
+ * space Space character (0x20)
+ * HH Hours 00-23
* : This is the REAL in sync indicator (: = insync)
- * MM minutes
+ * MM Minutes 00-59
* : : = in sync ? = NOT in sync
- * SS seconds
- * L leap second flag
+ * SS Seconds 00-59
+ * L Leap second flag. Changes from space (0x20)
+ * to '+' or '-' during month preceding leap
+ * second adjustment.
* +5 UT1 correction (sign + digit ))
- */
+ */
+
+ if (sscanf(pp->a_lastcode,
+ "%*4c %2c %4d%*c%3d%*4c %2d%c%2d:%2d%c%*2c",
+ char_quality, &pp->year, &pp->day,
+ &pp->hour, &syncchar, &pp->minute, &pp->second,
+ &leapchar) == 8) {
+
+ if (char_quality[0] == 'L') {
+ quality = 0;
+ } else if (char_quality[0] == '0') {
+ quality = (char_quality[1] & 0x0f);
+ } else {
+ quality = 99;
+ }
+
+/*
+#ifdef DEBUG
+ if (debug) {
+ printf("ulink: char_quality %c %c\n",
+ char_quality[0], char_quality[1]);
+ printf("ulink: quality %d\n", quality);
+ printf("ulink: syncchar %x\n", syncchar);
+ printf("ulink: leapchar %x\n", leapchar);
+ }
+#endif
+*/
- if (sscanf(pp->a_lastcode, "%*4c %2d %4d%*c%3d%*4c %2d%c%2d:%2d%c%*2c",
- &quality, &pp->year, &pp->day,
- &pp->hour, &syncchar, &pp->minute, &pp->second,
- &leapchar) == 8){
break;
}
&pp->msec,&leapchar) == 10) {
pp->msec *= 10; /* M320 returns 10's of msecs */
if (leapchar == 'I' ) leapchar = '+';
+ if (leapchar == 'D' ) leapchar = '-';
if (syncchar != '?' ) syncchar = ':';
break;
/*
* Decode quality indicator
- * the lower the number the "better" the time is
- * I used the dispersion as the measure of time quality
- * the quality indicator in the 320 is number of
- * correlating time frames (the bigger the better)
+ * For the 325 & 33x series, the lower the number the "better"
+ * the time is. I used the dispersion as the measure of time
+ * quality. The quality indicator in the 320 is the number of
+ * correlating time frames (the more the better)
+ */
+
+ /*
+ * The spec sheet for the 325 & 33x series states the clock will
+ * maintain +/-0.002 seconds accuracy when locked to WWVB. This
+ * is indicated by 'Lk' in the quality portion of the incoming
+ * string. When not in lock, a drift of +/-0.015 seconds should
+ * be allowed for.
+ * With the quality indicator decoding scheme above, the 'Lk'
+ * condition will produce a quality value of 0. If the quality
+ * indicator starts with '0' then the second character is the
+ * number of hours since we were last locked. If the first
+ * character is anything other than 'L' or '0' then we have been
+ * out of lock for more than 9 hours so we assume the worst and
+ * force a quality value that selects the 'default' maximum
+ * dispersion. The dispersion values below are what came with the
+ * driver. They're not unreasonable so they've not been changed.
*/
+
if (pp->lencode == LEN33X) {
switch (quality) {
case 0 :
* Decode synchronization, and leap characters. If
* unsynchronized, set the leap bits accordingly and exit.
* Otherwise, set the leap bits according to the leap character.
- * We can safely ignore the delete leap-second case. an astroid
- * hitting at a tangent angle is all that is likely
- * to speed the earths rotation up.
- */
+ */
if (syncchar != ':')
pp->leap = LEAP_NOTINSYNC;
else if (leapchar == '+')
pp->leap = LEAP_ADDSECOND;
+ else if (leapchar == '-')
+ pp->leap = LEAP_DELSECOND;
else
pp->leap = LEAP_NOWARNING;
projects / thirdparty / ntp.git / commitdiff
