Radio Timecode Formats (README.timecodes) Following are examples of the serial timecode formats used by various timecode receivers as given in the instruction manuals. These examples are intended only for illustration and not as the basis of system design. The following symbols are used to identify the timecode character that begins a subfield. The values given after this symbol represent the character offset from the beginning of the timecode string as edited to remove control characters. C on-time character (start bit) Y year of century T time of day D day of year or month/day A alarm indicator (format specific) Q quality indicator (format specific) ASCII line feed (hex 0a) ASCII carriage return (hex 0d) ASCII space (hex 20) In order to promote uniform behavior in the various implementations, it is useful to have a common interpretation of alarm conditions and signal quality. When the alarm indicator it on, the receiver is not operating correctly or has never synchronized to the broadcast signal. When the alarm indicator is off and the quality indicator is on, the receiver has synchronized to the broadcast signal, then lost the signal and is coasting on its internal oscillator. In the following uppercase letters, punctuation marks and spaces stand for themselves; lowercase letters stand for fields as described. Special characters other than , and are preceded by ^. Spectracom 8170 and Netclock/2 WWV Synchonized Clock (format 0) "i ddd hh:mm:ss TZ=zz" C A D T poll: ?; offsets: Y = none, D = 3, T = 7, A = 0, Q = none i = synchronization flag ( = in synch, ? = out synch) ddd = day of year hh:mm:ss = hours, minutes, seconds zz = timezone offset (hours from UTC) Note: alarm condition is indicated by other than at A, which occurs during initial synchronization and when received signal has been lost for about ten hours example: " 216 15:36:43 TZ=0" A D T Netclock/2 WWV Synchonized Clock (format 2) "iqyy ddd hh:mm:ss.fff ld" C AQY D T poll: ?; offsets: Y = 2, D = 5, T = 9, A = 0, Q = 1 i = synchronization flag ( = in synch, ? = out synch) q = quality indicator ( < 1ms, A < 10 ms, B < 100 ms, C < 500 ms, D > 500 ms) yy = year (as broadcast) ddd = day of year hh:mm:ss.fff = hours, minutes, seconds, milliseconds of day l = leap-second warning (L indicates leap at end of month) d = standard/daylight time indicator ( standard, D daylight) Note: alarm condition is indicated by other than at A, which occurs during initial synchronization and when received signal has been lost for about ten hours; unlock condition is indicated by other than at Q, with time since last lock indicated by the letter code A < 13 min, B < 1.5 hr, C < 7 hr, D > 7 hr. example: " 92 216 15:36:43.640 D" AQ D T TrueTime 468-DC Satellite Synchronized Clock (and other TrueTime receivers) "<^A>ddd:hh:mm:ssq" D T QC poll: none; offsets: Y = none, D = 0, T = 4, A = 12, Q = 12 hh:mm:ss = hours, minutes, seconds q = quality/alarm indicator ( = locked, ? = alarm) Note: alarm condition is indicated by ? at A, which occurs during initial synchronization and when received signal is lost for an extended period; unlock condition is indicated by other than at Q example: "216:15:36:43 " D T Q Heath GC-1000 Most Accurate Clock (WWV/H) "hh:mm:ss.f dd/mm/yy" C T A D poll: none; offsets: Y = none, D = 15, T = 0, A = 9, Q = none hh:mm:ss = hours, minutes, seconds f = deciseconds (? when out of spec) dd/mm = day, month yy = year of century (from DIPswitches) Note: 0?:??:??.? is displayed before synch is first established and hh:mm:ss.? once synch is established and then lost again for about a day. example: "15:36:43.6 04/08/91" T A D Y PST/Traconex 1020 Time Source (WWV/H) (firmware revision V4.01) "frdzycchhSSFTttttuuxx" "ahh:mm:ss.fffs" "yy/dd/mm/ddd" A Q T Y D poll: "QMQDQT"; offsets: Y = 0, D = 3 T = 1,, A = 11, Q = 13 f = frequency enable (O = all frequencies enabled) r = baud rate (3 = 1200, 6 = 9600) d = features indicator (@ = month/day display enabled) z = time zone (0 = UTC) y = year (5 = 1991) cc = WWV propagation delay (52 = 22 ms) hh = WWVH propagation delay (81 = 33 ms) SS = status (80 or 82 = operating correctly) F = current receive frequency (1-5 = 2.5, 5, 10, 15, 20 MHz) T = transmitter (C = WWV, H = WWVH) tttt = time since last update (minutes) uu = flush character (03 = ^C) xx = 94 (unknown) (firmware revision X4.01.999 only) a = AM/PM indicator (A = AM, P = PM, - 24-hour format) hh:mm:ss.fff = hours, minutes, seconds, milliseconds of day s = daylight-saving indicator ( standard, D daylight) yy = year of century (from DIPswitches) dd/mm/ddd = day of month, month of year, day of year Note: The alarm condition is indicated by other than ? at A, which occurs during initial synchronization and when received signal is lost for an extended period. A receiver unlock condition is indicated by other than "0000" in the tttt subfield at Q. example: "O3@055281824C00000394 91/08/04/216 15:36:43.640" T Y D T David L. Mills University of Delaware mills@udel.edu 23 October 1993