README.timecodes revision 290001 
1Radio Timecode Formats (README.timecodes)
2
3Following are examples of the serial timecode formats used by various
4timecode receivers as given in the instruction manuals. These examples
5are intended only for illustration and not as the basis of system
6design. The following symbols are used to identify the timecode
7character that begins a subfield. The values given after this symbol
8represent the character offset from the beginning of the timecode string
9as edited to remove control characters.
10
11C         on-time character (start bit)
12Y         year of century
13T         time of day
14D         day of year or month/day
15A         alarm indicator (format specific)
16Q         quality indicator (format specific)
17<LF>      ASCII line feed (hex 0a)
18<CR>      ASCII carriage return (hex 0d)
19<SP>      ASCII space (hex 20)
20
21In order to promote uniform behavior in the various implementations, it
22is useful to have a common interpretation of alarm conditions and signal
23quality. When the alarm indicator it on, the receiver is not operating
24correctly or has never synchronized to the broadcast signal. When the
25alarm indicator is off and the quality indicator is on, the receiver has
26synchronized to the broadcast signal, then lost the signal and is
27coasting on its internal oscillator.
28
29In the following uppercase letters, punctuation marks and spaces <SP>
30stand for themselves; lowercase letters stand for fields as described.
31Special characters other than <LF>, <CR> and <SP> are preceded by ^.
32
33Spectracom 8170 and Netclock/2 WWV Synchonized Clock (format 0)
34
35"<CR><LF>i  ddd hh:mm:ss  TZ=zz<CR><LF>"
36 C       A  D   T
37
38     poll: ?; offsets: Y = none, D = 3, T = 7, A = 0, Q = none
39     i = synchronization flag (<SP> = in synch, ? = out synch)
40     ddd = day of year
41     hh:mm:ss = hours, minutes, seconds
42     zz = timezone offset (hours from UTC)
43
44     Note: alarm condition is indicated by other than <SP> at A, which
45     occurs during initial synchronization and when received signal has
46     been lost for about ten hours
47
48     example: "   216 15:36:43  TZ=0"
49               A  D   T
50
51Netclock/2 WWV Synchonized Clock (format 2)
52
53"<CR><LF>iqyy ddd hh:mm:ss.fff ld"
54 C       AQY  D   T
55
56     poll: ?; offsets: Y = 2, D = 5, T = 9, A = 0, Q = 1
57     i = synchronization flag (<SP> = in synch, ? = out synch)
58     q = quality indicator (<SP> < 1ms, A < 10 ms, B < 100 ms, C < 500
59     ms, D > 500 ms)
60     yy = year (as broadcast)
61     ddd = day of year
62     hh:mm:ss.fff = hours, minutes, seconds, milliseconds of day
63     l = leap-second warning (L indicates leap at end of month)
64     d = standard/daylight time indicator (<SP> standard, D daylight)
65
66     Note: alarm condition is indicated by other than <SP> at A, which
67     occurs during initial synchronization and when received signal has
68     been lost for about ten hours; unlock condition is indicated by
69     other than <SP> at Q, with time since last lock indicated by the
70     letter code A < 13 min, B < 1.5 hr, C < 7 hr, D > 7 hr.
71
72     example: "  92 216 15:36:43.640  D"
73               AQ   D   T
74
75TrueTime 468-DC Satellite Synchronized Clock (and other TrueTime
76receivers)
77
78"<CR><LF><^A>ddd:hh:mm:ssq<CR>"
79              D   T       QC
80
81     poll: none; offsets: Y = none, D = 0, T = 4, A = 12, Q = 12
82     hh:mm:ss = hours, minutes, seconds
83     q = quality/alarm indicator (<SP> = locked, ? = alarm)
84
85     Note: alarm condition is indicated by ? at A, which occurs during
86     initial synchronization and when received signal is lost for an
87     extended period; unlock condition is indicated by other than <SP>
88     at Q
89
90     example: "216:15:36:43 "
91               D   T       Q
92
93Heath GC-1000 Most Accurate Clock (WWV/H)
94
95"<CR>hh:mm:ss.f     dd/mm/yy<CR>"
96 C   T        A     D
97
98     poll: none; offsets: Y = none, D = 15, T = 0, A = 9, Q = none
99     hh:mm:ss = hours, minutes, seconds
100     f = deciseconds (? when out of spec)
101     dd/mm = day, month
102     yy = year of century (from DIPswitches)
103
104     Note: 0?:??:??.? is displayed before synch is first established and
105     hh:mm:ss.? once synch is established and then lost again for about
106     a day.
107
108     example: "15:36:43.6     04/08/91"
109               T        A     D     Y
110
111PST/Traconex 1020 Time Source (WWV/H) (firmware revision V4.01)
112
113"frdzycchhSSFTttttuuxx<CR>" "ahh:mm:ss.fffs<CR>" "yy/dd/mm/ddd<CR>"
114          A   Q               T                   Y  D
115
116     poll: "QMQDQT"; offsets: Y = 0, D = 3 T = 1,, A = 11, Q = 13
117     f = frequency enable (O = all frequencies enabled)
118     r = baud rate (3 = 1200, 6 = 9600)
119     d = features indicator (@ = month/day display enabled)
120     z = time zone (0 = UTC)
121     y = year (5 = 1991)
122     cc = WWV propagation delay (52 = 22 ms)
123     hh = WWVH propagation delay (81 = 33 ms)
124     SS = status (80 or 82 = operating correctly)
125     F = current receive frequency (1-5 = 2.5, 5, 10, 15, 20 MHz)
126     T = transmitter (C = WWV, H = WWVH)
127     tttt = time since last update (minutes)
128     uu = flush character (03 = ^C)
129     xx = 94 (unknown) (firmware revision X4.01.999 only)
130
131     a = AM/PM indicator (A = AM, P = PM, <SP> - 24-hour format)
132     hh:mm:ss.fff = hours, minutes, seconds, milliseconds of day
133     s = daylight-saving indicator (<SP> standard, D daylight)
134
135     yy = year of century (from DIPswitches)
136     dd/mm/ddd = day of month, month of year, day of year
137
138     Note: The alarm condition is indicated by other than ? at A, which
139     occurs during initial synchronization and when received signal is
140     lost for an extended period. A receiver unlock condition is
141     indicated by other than "0000" in the tttt subfield at Q.
142
143     example: "O3@055281824C00000394 91/08/04/216  15:36:43.640"
144                             T       Y        D    T
145
146David L. Mills
147University of Delaware
148mills@udel.edu
14923 October 1993
150