Rec. ITU-R TF.583-5 1
RECOMMENDATION ITU-R TF.583-5*
Time codes
(Question ITU-R 110/7)
(1982-1990-1994-1995-1997-2001)
The ITU Radiocommunication Assembly,
considering a) that in many branches of science and technology there is a need for the dating of events which requires knowledge of the date (year, month, day) and clock time; b) that this information can be transmitted in coded form at relatively low bit rates; c) that such coded transmissions require relatively small bandwidths resulting in economic spectrum use and enhanced reliability in the received information; d) that such codes are in increasingly widespread use and can be disseminated by both AM and FM broadcast services in appropriate data channels without impairing the prime service; e) that Universal Coordinated Time (UTC) related date and time information in digital form are available via modem in a number of countries on telephone networks; f) that it is important that such sources of time reference should conform with the standard for time signal emissions (see Recommendation ITU-R TF.460); g) that commercial production now exists of low-cost radio-controlled clocks, operating from services in band 5, for both public and private use,
recommends
1 that this form of time dissemination should be encouraged;
2 the introduction of new services in areas not adequately served and also the employment of existing transmitters for time code dissemination;
3 that when a time code is operational its time-keeping should conform to the standard laid down in Recommendation ITU-R TF.460, i.e. the disseminated time should not differ from UTC by more than 1 ms;
4 that where a new service of time code dissemination is introduced its format (coding and modulation) should conform when practicable with an existing service (see Annex 1).
______
* This Recommendation should be brought to the attention of Radiocommunication Study Group 6. 2 Rec. ITU-R TF.583-5
ANNEX 1
Information on coded timing
Coded timing information is conveyed in a variety of formats and transmission media. In many cases such information is disseminated in a broadcast mode either on dedicated time and frequency services or as a part of other types of broadcasts primarily intended for other purposes. Time code broadcasts are currently available using amplitude modulation, frequency modulation and phase modulation techniques. Other forms of time codes have been developed and are in wide use for transmitting time information directly from one piece of equipment to another via hardwired or other types of connection. In the remainder of this Annex some specific examples are provided both for the broadcast and the instrumentation time code types. While these codes are all currently available and widely used in at least some parts of the world, they are only representative of the total variety of codes that are in use. Examples of broadcast codes include those transmitted by the time services of WWV/WWVH, WWVB, MSF, OMA, JG2AS, JJY, DCF 77, ATA, VNG, CHU, RBU and IAM, the code generated by IEN and disseminated on the AM and FM networks by the Italian broadcasting company RAI, and by the United States GOES satellite system (see Figs. 1 to 15). To illustrate the instrumentation type of codes, several of the specific formats recommended by the United States of America Inter- Range Instrumentation Group (IRIG) are shown in Fig. 14. An example of telephone time codes which shows the format of the code used in several European countries is given in Fig. 16. This code is now available from the primary timing centres of the following countries: Austria, Belgium, Germany, Italy, the Netherlands, Poland, Portugal, Romania, Spain, Sweden, Switzerland, Turkey and the United Kingdom. The time code used in the Swiss transmitter HBG is given in Fig. 17.
Rec. ITU-R TF.583-5 3
FIGURE 1 WWV/WWVH time code format
Seconds
59 01 2 On time point A 1 s 0.170 s 0.170
0.770 s 1.03 s hole Time frame: 1 min (index count: 1 s)
0 1020304050 0
P P P P P P P 0 1 2 3 W 4 1 s 5 0 0.8 s 1 2 4 8 1 4 8 1 2 4 8 1 2 4 8 2 10 20 40 10 20 10 20 40 80 10 20 40 80 0.1 0.2 0.4 100 200 Units Minutes Hours Days of year R Sign ( ) for Leap second warning UT1 correction DST indicator No. 2 (see text) UT1 Tens of year correction DST indicator No. 1
Modified IRIG H format is composed of the following:
1 ppm frame reference marker R = (P0 and 1.03 s “hole”) Binary coded decimal year and time-of-year code word
6 ppm position identifiers (P0 through P5) 1 pps index markers
P0-P5: position identifiers (0.770 s duration) W: weighted code digit (0.470 s duration) Duration of index markers, unweighted code, and unweighted control elements: 0.170 s
Note 1 - Beginning of pulse is represented by positive-going edge. UTC at point A: 1990, 173 days, 21 h, 10 min UT1 at point A: 1990, 173 days, 21 h, 10 min, 0.3 s 0583-01
4 Rec. ITU-R TF.583-5
FIGURE 2 WWVB time code format
O n tim e p o in t A
Time fram e: 1 min (index count: 1 s)
010203040500
P P P P P P P 0 0.8 s1 2 0.2 WUs3 4 5 0.5 0s 0.8 s 8 4 2 1 8 4 2 1 8 4 2 1 8 4 2 1 40 20 10 20 10 40 20 10 40 20 10 80 80 200 100 800 400 200 100 Sub Add Add UT1 M inutes H ours D ays Y ear sign U T 1 co rrectio n
D aylight savings tim(see e b its text Leap year indicator for interpretation bit of bits) 0: non leap year 1: leapLeap year second warning bit
1 ppm fram e reference markers B inary coded decimal year and time-of-year code word (31 bits)
6 p p m p o sitio0th n roid5) u e gh n tifie P r m a rk e rs (P (re d u c e d c a rrie r 0 .8 s d u ra tio n + 0 .2 s d u ra tio n p u ls e ) W : w e igh te d c o d e d igit (c a rrie r re s to re d in 0 .5 s , b in a ry o n e ) U : unw eighted code digit (carrier restored in 0.2 s, binary zero)
U TC at point A: 1990, 258 days, 18 h, 42 min U T1 at point A: 1990, 258 days, 18 h, 41 min, 59.3 s
0583-02
Rec. ITU-R TF.583-5 5
FIGURE 3 MSF time code format
H M D N
2010 8 4 21 40 20108 4 2 1 201084 2 1 1084 2 1
60 kHz 60 kHz carrier carrier
Marker bit Parity Parity bit Summer bit Control pulse time
0 25 50 100 200 300 330 500 ms
Minute marker
Example above: 29 September, 1248 UTC, during summer time
a) MSF fast code format (60 kHz)
Y N V1 804020108421108421
012345678910111213141516–43–42–41–40–39–38–37–36–35–34–33–32–31Seconds DUT1 (V2) L
DoM DoW H M MI V2 20 10 8 4 2 1 4 2 1 20 10 8 4 2 1 40 20 10842101111110
–30 –29 –28 –27 –26 –25 –24 –23 –22 –21 –20 –19 –18 –17 –16 –15 –14 –13 –12 –11 –10 –9 –8 –7 –6 –5 –4 –3 –2 –1 Seconds
V1 V2 ST (H + M)P 0 0 (DoW)P V2 (N + DoM)P 0 1 YP STC 1 0
1 1
300 ms 200 ms 100 ms Seconds mark H: hour Y: year ST: summer time DoM: day-of-month M: minute V: level STC: summer time change DoW: day-of-week D: day L: leap second insertion MI: minute identifier 0 = Sunday to N: month P: parity check bits SR: seconds mark 6 = Saturday 0583-03 b) MSF slow code format (60 kHz) 6 Rec. ITU-R TF.583-5
FIGURE 4 OMA time code format (50 kHz)
Time of day (CET) 10 h 00 min 10 h 01 min
0 5455565758590
0.5 s 0.1 s 0.1 s
M P1 P2 P3 P4 M OMA
(UM + 1 s) = 2 s (TM + 1 s) = 1 s(UH + 1 s) = 1 s (TH + 1 s) = 2 s
AM second mark AM minute mark
56 s Detail P2
0 100 150 250 ms
Phase reversal
UM: units of minutes TM: tens of minutes UH: units of hours TH: tens of hours 0583-04
Rec. ITU-R TF.583-5 7
FIGURE 5 JJY (40 kH z) tim e code form at
O n tim e p o in t A Time fram e: 1 min (index count 1 s) 010203040500
F ram e referen ce m ark er 0.2 s W : 0 .5 s U : 0 .8 s 8 4 2 1 4 2 1 8 4 1 2 8 4 2 1 4 2 1 8 M M 20 10 40 80 40 20 10 10 40 20 20 80 10 P3 P0 P1 P5 P2 P4 "0" "0" "0" "0" "0" "0" "0" "0" "0" "0" "0" "0" "0" 200 100 LS1 LS2 PA 1 PA 2 SU 1 SU 2 M inutesHours Days Year Parity Day of L eap second Reservedthe w eekin fo rm atio n a) Form at A M , P 0 -P 5 : p o sitio n m a rk e rs (c a rrie r o f 0 .2 s d u ra tio n ) W : w eighted code digit (carrier of 0.5 s duration) U : unw eighted code digit (carrier of 0.8 s duration) PA 1: even parity for hours PA 2: even parity for minutes "0": alw ays binary zero JST at point A: 269 day of 1999, 15 h 35 min, Sunday, no leap second is planned within one month SU 1 and SU 2 are reserved to deal w ith future expansions concerning tim e inform ation O n tim e p o in t A Time fram e: 1 min (index count 1 s) 010203040500
F ram e referen ce m ark er 0.2 s W : 0 .5 s U : 0 .8 s 1 2 8 4 8 4 2 1 8 4 2 1 M M 40 20 40 10 20 80 10 20 10 P3 P0 P1 P2 P4 P5 "0" "0" "0" "0" "0" "0" "0" "0" "0" "0" "0" "0" "0" 200 100 PA 1 PA 2 M inutesHours Days C a ll sign Station Parity m a in te n a n c e in fo rm atio n b) Form at B JST at point A: 269 day of 1999, 15th, 15 h 45 min, Sunday
M ark: M , P0-P5 M ark: binary one M ark: binary zero
Space Space Space 1 0 % o f a m p litu d e 1 0 % o f a m p litu d e
200 ms500 ms 800 ms
E xact tim e (s) E xact tim e (s) E xact tim e (s) E xact tim e (s) c) W ave form N o teThe 1 time- code form at A is transm itted except in the 15th and 45th minutes when the time code form at B is transm itted.
0583-05
8 Rec. ITU-R TF.583-5
FIGURE 6 JJY time code format
a) Hourly modulation schedule
9 1929394959 min
051015 20 25 30 35 40 45 50 55 0 min Second pulses and Second pulses 1 000 Hz tone only Second pulses and No emission identifying signals
b) Wave form of second pulses
1 000 Hz tone Non 1 600 Hz Non 1 000 Hz tone or non modul. modul. tone modul. or non modul.
JJY emission schedule 40 ms 5 ms 40 ms
Exact time (s)
c) Identification of minute signal by preceding marker
1 000 Hz tone 600 Hz 1 000 Hz tone or non modul. 59 s tone 00 s or non modul.
40 ms 40 ms655 ms 300 ms 40 ms
5 ms 5 ms
d) Identifying signals Call sign: 2 by the Morse code Time in JST: 1 by the Morse code Call sign: 2 in voice Time in JST: 1 in voice Radio propagation warning by the Morse code: (N: normal, U: unstable, W: disturbed)
Example: DUT1 = - 0.5 s 57 58 59 0 1 2 3 4 5 6 7 8 9 s
5 ms 655 ms 45 ms (1 600 Hz) (600 Hz) (1 600 Hz) Second Preceding marker Lengthened pulse for minute second pulses Method of indicating DUT1 on JJY Example: DUT1 = - 0.2 s 6 7 8 9101112131415161718 s
0583-06 Rec. ITU-R TF.583-5 9
FIGURE 7 DCF-77 time code frame
P3 M Year 40 80 Coding 20 10 when 8 required 4 0 2 1 10 50 10 Month 8 4 2 1 R 4 A1 Day of 2 Z1 the week 1 40 20 Z2 20 A2 10 S 8 1 4 30 2 Calendar 2 4 1 8 day P2 10 20 40 20 10 8 4 2 1 P1 Minute
Hour
Coding scheme M: minute marker (0.1 s) R: second marker No. 15 has a duration of 0.2 s when the standby antenna is used A1: announcement of a forthcoming change from CET to CEST or vice versa Z1, Z2: zone time bits A2: announcement of a leap second S: starting bit of the coded time information (0.2 s) P1, P2, P3: parity check bits
The second markers Nos. 17 and 18 indicate the time system to which the transmitted time information is related. In the case of CET, the second marker No. 18 has a duration of 0.2 s and the second marker No. 17 a duration of 0.1 s. When CEST is emitted this order is reversed. Furthermore, a forthcoming change from CET to CEST or from CEST to CET is indicated by second marker No. 16. During one hour before the change, second marker No. 16 is emitted as a prolonged marker. When time is changed from CET to CEST (from CEST to CET), the prolonged second marker No. 16 is emitted for the first time at 0100.16 h CET (0200.16 h CEST) and for the last time at 0159.16 h CET (0259.16 h CEST). The second marker No. 19 serves to announce that a leap second is intercalated and it is also emitted as a prolonged marker for one hour prior to the intercalation of the leap second. When a leap second is inserted, the associated minute has a duration of 61 s and the 59th second marker preceding the marker 01.00.00 h CET or 02.00.00 h CEST is emitted with a duration of 0.1 s. The marker associated with the intercalated 60th second is transmitted without carrier reduction. The three parity check bits P1, P2 and P3 complete the preceding information words (7 bits for the minute, 6 bits for the hour and 22 bits for the date, including the number of the day of the week) to form an even number of binary ones (duration 0.2 s). 0583-07 10 Rec. ITU-R TF.583-5
FIGURE 8 ATA time code format
58th second 59th second 60th second 1st second 2nd second
5995 5 995 100 900 5 995 5
Tone (1 kHz) Tone (1 kHz) 10 5 10
Tone (1 kHz) Tone (1 kHz) 10 100 10
Time (ms) 0583-08
Rec. ITU-R TF.583-5 11
FIGURE 9 VNG time code format
Seconds markers normally 50 ms of 1 000 Hz Minute Seconds markers 55-58 are 5 ms of 1 000 Hz pulse Seconds marker 59 omitted Minute marker is 500 ms of 1 000 Hz sharing 5th, 10th, 15th etc. minutes, Seconds markers 50-58 are 5 ms of 1 000 Hz Minute + identifier 58 59 0 1 2 DUT1 56 57 3 4 55 5 transmission 54 Seconds past 6 53 each minute 7 52 8 – 51 9 50 10 Normal seconds markers 49 11 of 50 ms of 1 000 Hz 48 12 emphasized by 50 ms of 47 13 P3 900 Hz, tone immediately 46 14 following 200 45 15 100 44 16 80 43 17 42 18 40 41 19 Seconds marker 20 20 40 20 200 ms duration 10 39 21 S designates the start of Day of 38 22 8 37 23 1 the time information the year 4 36 24 2 2 35 25 4 3433 2726 1 32 31 30 29 28 8 P2 10 Time code 20 20 10 40 transmission (UTC) – valid at next minute 8 4 2 1 P1 Minute Binary “0” 100 ms duration Hour Binary “1” 200 ms duration Parity check bits P1, P2, P3 counting binary “1’s” of each group plus the corresponding parity bit gives an even number 0583-09
12 Rec. ITU-R TF.583-5
0583-10 32.500 bits bits 2 stop 2 2 stop 2 (0 .1 s ) o f1 0 0 0 H z DUT1
Nseconds orm al
Pulses 300 periods 300 Pulses part bi ort sni le b ib n is th r fo it b rity a p n e v E in s e c o n d 3 1 in s e c o n d 3 2
to b e r.)
1 for leap second scheduled second leap for 1 2 Code of byte Last First byte of Code 1 Code of byte First
1 for + leap second scheduled second leap + for 1 g ofDUT1 0 +) + = (0 1 T U D f o ign S 12481248 12481248 bit bit 9 seconds9 pulsesom itted - quatorze heures zéro minutes. zéro heures quatorze - follow ing each hour pulse hour each ing follow Start Start 31.133 2 225 Hz 225 2 Hz 025 2 Hz 225 2 Hz 025 2 1 000 Hz 000 1 H our pulse H our
1 000 periods of periods 000 1 announcem ent Station and tim e and Station
itte da th t e t n i r e b m u N l ria e S s rn tte a P
s an ihtTi e im 40T 49 50 51 52 53 t 54 55 56 57 58 59 1 ligh 2 y 3 a 4 5D 6 7 8 n 9 10 11 12 ia d a n a C A nnouncem ent: C H U Canada, Coordinated U niversal Tim e: fourteen hours zero m zero inutes hours Cfourteen Tim H U e: UCoordinatedCanada, niversal 39 38 min TAI- 37 UTC (s) UTC 36 h FIGU RE 10 FIGU RE 35 34 year CHU time code format code time CHU Gregorian 33
Day 32 ) s .1 (0 1 T U D 9 Code groups: Code 9
Second 31: Code2 1 Second 31: Code 32-39: Seconds
31 a eodifr ation inform second eap L 6012135932 0119932700 L S B : s ign o f D U T 1 30 d e te c t o n , o r s e t m o d e m c a rrie r d e te c t tim e to 0 .1 so r le s s . C H U FSK Time Codes (UTC ): 1 Code 1 and 8 Code 2 groups. 2 Code 8 and 1 Code 1 C (UTC HCodes FSK U ): Time 29 95, 23. The end of the last stop bit of the group is transm is group the of bit stop last the of end The 23. 95, o m itte d half-second. Each group is preceded by 0.01 s of 1 000 Hz and 0.123 s 0.123 and Hz 000 1 of s 0.01 by preceded is group Each half-second. 8 d a ta b its n , o p a rity , 1 s ta rt b it a n d 2 s to p b its ),m o s t c o m p u te rs w o u ld D e c o d e dw ithB e1 ll 0 3c o m p a tib lem o d e m(in o rigin a te m o d e3 , 0 0b it/s, o f 2 2 2 5 H z c a rrie r, a n d is fo llo w e d b y 0 .0 1 so f c a rrie r. S e t m o d e m c a rrie r Pulse at 29 s 29 at Pulse C 6 , 8 D F , F ; a n d w o u ld re c e iv e th is C o d e 2 a s0 62 , 1 , 3 1 , 9 5 , 2 3 , 0 6 , 2 1 , 3 1 , re c e iv e th is C o d e 1 a s th e s trin g (in h e x a d e c im a l) 1 0 , 9 1 , 3 9 , 7 2 0 , 0E , F , 6 E , 32728 D U T1 = + 0.1 s 0.1 + = D U T1 2 225 Hz 225 2 Hz 225 2 31.510 32.510 o n esp p lit u lsein d ic a te s E xam ple of DE xam of U T ple code: 1 5 byte 5 2: Code 5 byte 5 1: Code - thirteen hours fifty-nine minutes. fifty-nine hours thirteen - 1 000 Hz 000 1 M inute pulse M inute 500 periods of periods 500 C H U broadcast codes: exam ple for the period 13:58:46 to 14:00:13 UTC on 12 January, 1993 (day 012 of the year): the of 012 (day 1993 January, UTC12 on 14:00:13 to 13:58:46 period the for exam ple codes: C Hbroadcast U announcem ent Station and tim e and Station Time (s) Time (s) Time C ode 2C ode 2 C ode (D U T 1 =+ 0 .1 s , T A I-U T C = 2 7 s , n ole a p s e c o n d th is q u a rte r, C a n a d ia n D a y ligh t T im efirs t S u n d a y o f A p rilto la s t S u n d a y o fO c C ode 1C ode 1 C ode 10 periods of 1 000 Hz 000 1 of periods 10 Hz 000 1 of periods 10 o f1 0 0 0 H z 47 48 49 50 51 52 53 54 55 56 57 58 59 1 2 4 Nseconds orm al Pulses 300 periods 300 Pulses 31.010 32.010 C H U Canada, tem ps universel coordonné: treize heures cinquante-neuf minutes cinquante-neuf heures treize coordonné: universel ps Ctem H Canada, U 31.000 31.133 31.317 31.500 32.000 32.133 32.317 32.500 Announcem ent: C Hgroups: FSK UCode 13:58:46 UTC 13:58:46 UTC 13:59:00 UTC 14:00:00 UTC 14:00:13
Rec. ITU-R TF.583-5 13
w UT1 m M + d M + m h Y ∆ d
0583-11 SM
0 1
60
1 2
1 4
1 8
1 10
1 20
1 40
1 1
1 2
1 4
1 8
50
10
20
1
2 1 2
PM 100/312.5 Hz 4
SM
m 8 TJD
d 10
20
1 2
w 40 5(ms)
d 4 : 0.1 s interval numbers
1 Reserved intervals
28th s 28th Reserved intervals
2
4 0, 1, 1, 2,... 0, 8
Parity bits 1 10
2 1
4 2
8 4
10
8 1 30
20
YN10 hm
FIGURE 11 FIGURE PM 312.5 Hz
40
SM 20
80 40
80
100 format code time RBU b) a) RBU broadcast format broadcast RBU a)
0 200
27th s 28th s 29th s
1
10 80 5 100 400
2 800
RBU broadcast and time code format code time and RBU broadcast
4 1 000 1 2
8
UT1 000 2
312.5 Hz modulation
∆ 10
4 000 4
20
8 000 8
± 0 0 0 –
– ±
9 1
– 1
– 1
–
SM (second marker) 1
PM 100 Hz – 0
– 0
10
– 00 s 00 0 dUT1 +
DUT1 TJD
± + 1
+ 1
+ 1
+
100 Hz modulation 1
+ 0
+ 0
+ 8012 1 567890123 678901234567890123456789012 1 : a day of the month the : of day a : a day of the week the : of day a 0 UT1: the difference between the universal time and the UTC (SU) m w B d A: first 0.1 s interval B: second 0.1 s interval ∆ Y: a year of century M: a month of the current year d DUT1: (resolution 0.1 s) s) 0.02 (resolution dUT1: A Minute marker Minute
PM - sine phase modulation with 0.698 index 0.698 with modulation phase - sine PM
14 Rec. ITU-R TF.583-5
FIGURE 12 IAM time code format
Time signal Time signal Time signal Time signal
0730 0735 0745 0750 0800 0805 0815 0820 0830 1030 1035 1045 1050 1100 1105 1115 1120 1130
A3 Announcement Time signal in A3
Time is given in slow-speed telegraphy at 0735, 0750, 0805, 0820, 1035, 1050, 1105 and 1120 h UTC. During summer time, the emissions are advanced by 1 hour. Transmission schedule of IAM. 0583-12
Rec. ITU-R TF.583-5 15
FIGURE 13 GOES time code format
0.5 s 0.5 s 0.5 s 0.5 s
TC Interrogation TC Interrogation TC Interrogation TC Interrogation word message word message word message word message
30 s
Time code frame consisting of: - synchronization word - days, hours, minutes, seconds - UT1 time correction; accuracy, DST and leap second indicators - satellite position
a) GOES satellite interrogation channel format
40 32 8 20 16 16 180 Synchro- Time of Accuracy, DST, nization year and leap second
word Radius information Latitude Longitude
Satellite UT1 time position corrections
30 s time frame Begins on 00 and 30 s UTC b) GOES time code format 0583-13
16 Rec. ITU-R TF.583-5
0 5 P P 0583-14A 16 2 15 2 Seconds 14 2 0.1 0.2 0.4 0.8 13 2 12 2 11 2 10 2 9 2 4 9 P P 8 2 7 2 (T im eo d f ay ) 6 2 5 2 0.001 s (typical) s 0.001 4 2 Straight binary seconds 17 bits 17 seconds binary Straight 3 2 2 2 1 2 0 2 8 3 P P T im ea th t isp o in t: 173 days, 21 h, 18 min, 42.875 s. 42.875 min, 18 h, 21 days, 173 Index count: ms count: Index FIGURE 14 FIGURE Time fram e: 0.1 s 0.1 e: fram Time IR IG s p e c ific fo r m a ts 7 2 P P M inutes H ours D ays C ontrol functions C ontrol 0.8 ms position identifier (typical) identifier position ms 0.8 T y p ic am l R ecom oH00010 m d z ufrequency: ended la te dc a rrie r 6 1 P P 0.2 ms binary 0 (typical) 0 binary ms 0.2 (typical) 1 binary ms 0.5 0.001 s index marker index s 0.001 8 10 20 40 1 2 4 8 10 20 40 1 2 4 8 10 20 1 2 4 8 10 20 40 80 100 200 R eferen cetim e Seconds 0.01 s index marker index s 0.01 R eferen cem ark er 0.8 ms 0.8 X 124 FORM AT A FORM AT 0 1020304050 50 60 70 80 90 0 5 0 P P 3.3X
Rec. ITU-R TF.583-5 17
0 5 P P 0583-14B 16 2 15 2 14 2 13 2 12 2 11 2 10 2 9 2 4 9 P P 8 2 7 2 (T im eod f ay ) 6 2 5 2 0.01 s (typical) s 0.01 4 2 Straight binary seconds 17 bits 17 seconds binary Straight 3 2 2 2 1 2 0 2 8 3 P P
) 173 days, 21 h, 18 min, 42.750 s. 42.750 min, 18 h, T21 im edays, a th t 173 isp o in t: c o n tin u e d Time frame: 1 s 1 frame: Time Index count: 0.01 s 0.01 count: Index FIGURE 14 ( 14 FIGURE 7 2 P P P o inA t C ontrol functions C ontrol 8 ms position identifier (typical) identifier position ms 8 Typical modulated carrier modulated HzTypical 000 1 R ecomfrequency: m ended 6 1 P P 0.01 s index marker index s 0.01 8 10 20 40 1 2 4 8 10 20 40 1 2 4 8 10 20 1 2 4 8 10 20 40 80 100 200 R eferen cetim e Seconds M inutes H ours D ays 0.1 s index marker index s 0.1 8 ms8 (typical) 0 binary ms 2 (typical) 1 binary ms 5 R eferen cem ark er X 124 FORM AT B FORM AT 0 1020304050 50 60 70 80 90 0 5 0 P P 3.3X
18 Rec. ITU-R TF.583-5 0583-14C 4 8s p o sitioid n e n tifie r(ty p ic a l) 5 P 4 P 1 min (typical) min 1 3 P
) c o n tin u e d (
H ours D ays Time frame: 1 h 1 frame: Time Index count: 1 min 1 count: Index 3 0 s b in a ry 1 (ty p ic a l) FIGURE 14 14 FIGURE 1 2 4 8 10 20 1 2 4 8 10 20 40 80 100 200 2 P 10 min index marker index min 10 1 m in in d e xm a rk e r Typical modulated carrier carrier modulated Typical Hz 100 R ecomfrequency: m ended 0 1 1 2 s b in a ry 0 (ty p ic a l) P P 173 days, 21 h, 57 min 57 h, T21 im edays, a th t 173 isp o in t: R eferen cetim e C ontrol functions C ontrol R eferen cem ark er 48 s 48 X FORM AT D FORM AT 0 1020304050 50 0 5 0 P P 3.3X
Rec. ITU-R TF.583-5 19 0583-14D 0.8 s position position s 0.8 id e n tifie r(ty p ic a l) 5 P 4 P 1 s (typical) s 1 3 P
) c o n tin u e d H ours D ays Index count: 1 s 1 count: Index Time frame: 1 min 1 frame: Time 0.5 s binary 1 (typical) (typical) 1 binary s 0.5 FIGURE 14 ( 14 FIGURE 1 2 4 8 10 20 1 2 4 8 10 20 40 80 100 200 2 P 40 Minutes R ecom m ended frequency: 100 Hz or 1 000 Hz 000 1 Tor Hz y 100 p ic am l R ecomfrequency: m o ended d u la te dc a rrie r 1 2 4 8 10 20 0 1 P P 0.2 s binary 0 (typical) 0 binary s 0.2 173 days, 21 h, 24 min, 57 s 57 min, 24 h, T21 im edays, a th t 173 isp o in t: R eferen cetim e C ontrol functions C ontrol R eferen cem ark er 0.8 s 0.8 X FORM AT H FORM AT 0 1020304050 50 0 5 0 P P 3.3X
20 Rec. ITU-R TF.583-5
0583-15 480 ms 480 20 10 8 4 2 1 40 20 10 8 4 2 1 ID YR WS WL PA 0123456789101112131415 1 0 ID: code segment identifier YR: units) and (tens year time/DST solar change: WS: on warning 111 days 7 next in the no change 110 6 days within foreseen change 001 day 1 second within leap on foreseen WL: change warning 000 time solar to 0300 at or to DST switches at 0200 00 month the within second no leap 10 PA: bit parity odd month the of end the at 1 s delay 11 month of the end at the 1 s advance Second segment Acoustic reference pulses reference Acoustic date code date FIGURE 15 0.96 0.48 s 0.1 IEN/RAI time code format 51 52 53 54 55 56 57 58 59 00 01 s = 2.5 kHz f 30 ms30 ms 30 = 2 kHz f code 960 ms 960 segment First date First 00410004110842120108421421 201084214020108421 ID: code segment identifier HR: hours (tens and units) MI: units) and (tens minutes ST: “0” solar time, “1” summer time (DST) P1: 2 to bit 15) (from group information first of bit the odd parity units) and (tens MO: month units) and (tens month the of DM: day week the of day DW: P2: 30) to 17 bit (from group information second the of bit parity odd ID HR MI ST P1 MO DM DW P2 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31
1 0
Rec. ITU-R TF.583-5 21
FIGURE 16 European telephone time code format
Each second a string of 80 ASCII characters is sent containing date and time information of the next second. The example below shows the time code (line 3) and marks the character position (lines 1 and 2) as well as the items described later on (lines 4 and 5).
1 1020304050607080
1993-06-07 08:23:58 CEST 12315809260319930607062349145-3 + 060501 XXX *
ABCDEFGHIJKLMNOPQRSUVYT WX Z a
Local time UTC Infos and time marker
Terms related to local time A: Year B: Month C: Day D: Hour E: In some countries there is a liability to mark the hour when switching from daylight saving time (DST) to standard time (ST), therefore the following option exists; the delimiter “:” normally used may change to “A” during the last hour of DST and to “B” during the first hour of ST. F: Minute G Second H: The local time identifier reveals the time zone and which local time (ST or DST) is currently used. I: Day of week (1 to 7 starting on Monday). J: Week of the year K: Day of the year L: Month/next change of local time from DST to ST or vice versa M: Day/next change of local time from DST to ST or vice versa N: Hour/next change of local time from DST to ST or vice versa
Terms related to UTC O: Year P: Month Q: Day R: Hour S: Minute The minute of UTC and local time may differ, because the offset between these two time scales should not be a multiple of hours. T: Modified Julian date (MJD) MJD is a continuous counting of days since 17 November 1858. U: DUT1 in tenths of seconds DUT1 is the difference between Universal Time and Universal Time Coordinated (UT1 – UTC). V: Announcement of leap second (sign and mouth) At the end of the last day of the month the leap second will be introduced according to the positive (+) or negative (–) sign. Three zeroes on these places indicate, that no leap second is announced.
Messages and time reference W: Delay compensation in milliseconds Indicates the value the code is advanced with respect to the time scale of the laboratory operating the generator (see Z). X: Message sequence number (0 to 9). Indicates the line number of the message (see Y). Y: Message Up to a maximum of 10 lines, 14 characters each, contains a laboratory dependent message. Z: Visible time marker Usually this character is “*”, but it changes to “#” if the code is advanced according to a delay measurement made by the generator. a: Time marker The time reference is the leading edge of the start bit of