chuck@trantor.harris-atd.com (Chuck Musciano) (04/04/89)
> Looking for a program that will dial up and read the time from National > Bureau Standard and then set the local computer clock.. This might be harder than you think, unless you have a special number for NBS. If you call (303) 499-7111, you'll get the audio that is broadcast from WWV, in Fort Collins, Colorado. The time is announced each minute, and you get a tick each second. If you listen closely, you'll hear the tick, plus a varying length 100 Hz tone. The length of the tone represents either a zero or a one, and the first forty five ticks are used to encode the current time of day and day of the year, plus any correction for UTC and tenths of leap seconds applied to the time. In addition, you can get the station ID at the top of the hour, western hemisphere storm information at 8, 9, and 10 minutes after the hour, the Omega report at 16 after (Omega is a very low frequency navigation aid, and the report gives the current signal degradation), and geo alerts at 18 after (geo alerts give the current state of solar flares and the geomagnetic field). The geo alerts have been pretty active with the current round of solar flares occuring. I would suggest that the easiest way to solve your problem is to buy a Heathkit "Most Accurate Clock" ($275) with the serial interface ($50) and attach it to your Sun. It will deliver the time each minute to your machine. I seem to recall, though, some items in sun-spots detailing a voltage problem in the clock's serial board which meant you had to do something special to get it to work with Suns. Chuck Musciano Advanced Technology Department Harris Corporation (407) 727-6131 ARPA: chuck@trantor.harris-atd.com
smb@arpa.att.com (04/26/89)
> Looking for a program that will dial up and read the time from National > Bureau Standard and then set the local computer clock.. This might be harder than you think, unless you have a special number for NBS. Dial 303-494-4774, at 1200 baud. I've heard there's supposed to be a 900 number, but I don't know what it is. 900-555-1212 says that 900-410-8463 is the Naval Observatory, but I don't know if it's voice or data; my modem didn't connect just now, but the switch here may be programmed to disallow 900 numbers. The Heath Most Accurate Clock can be problematic; reception isn't always that good in computer rooms, and a decent antenna seems to be essential.
mcgraw@sunspot.noao.edu (Robert McGraw) (04/26/89)
Try NBS at (303) 494-4774 with a 300 or 1200 modem at 8N1. Will give the time ever second and corrects for delays in phone transmissions. The number is going to change to a 900 number in the future.
brent@uunet.uu.net (Brent Chapman) (04/27/89)
# This might be harder than you think, unless you have a special number for
# NBS. If you call (303) 499-7111, you'll get the audio that is broadcast
# from WWV, in Fort Collins, Colorado....The length of the tone
# represents either a zero or a one, and the first forty five ticks are used
# to encode the current time of day and day of the year, plus any correction
# for UTC and tenths of leap seconds applied to the time.
This is what the person in Sun-Spots was asking about, I believe. It's a
normal dialup service, not some wierd audio signal.
-Brent
--
Brent Chapman Capital Market Technology, Inc.
Computer Operations Manager 1995 University Ave., Suite 390
brent@capmkt.com Berkeley, CA 94704
{cogsci,lll-tis,uunet}!capmkt!brent Phone: 415/540-6400
------- Forwarded Message
cook@trane.UUCP (Eric Cook):
Your tax dollars at work......
I found this in Sky & Telescope. If you are doing projects requiring
your computer syncing with UTC, this is for you. The phone number is
(303) 494-4774, they are to add a 900 number in the future.
DESCRIPTION OF THE
AUTOMATED COMPUTER TELEPHONE SERVICE (ACTS)
The following is transmitted (at 1200 baud) following completion of the
telephone connection.
? = HELP
National Bureau of Standards
Telephone Time Service
D L D
MJD YR MO DA H M S ST S UT1 msADV OTM
47222 88-03-02 21:39:15 83 0 +.3 045.0 UTC(NBS) *
47222 88-03-02 21:39:16 83 0 +.3 045.0 UTC(NBS) *
47222 88-03-02 21:39:17 83 0 +.3 045.0 UTC(NBS) *
47222 88-03-02 21:39:18 83 0 +.3 045.0 UTC(NBS) *
47222 88-03-02 21:39:19 83 0 +.3 037.6 UTC(NBS) #
47222 88-03-02 21:39:20 83 0 +.3 037.6 UTC(NBS) #
etc..etc...etc.......
UTC = Universal Time Coordinated, the official world time referred to the
zero meridian.
_________________________________________________________________________
DST = Daylight savings time characters, valid for the continental U.S., are
set as follows:
00 = We are on standard time (ST). 50 = We are on DST.
99 to 51 = Now on ST, go to DST when your local time is 2:00 am and the
count is 51. The count is decremented daily at 00 (UTC).
49 to 01 = Now on DST, go to ST when your local time is 2:00 am and the
count is 01. The count is decremented daily at 00 (UTC).
The two DST characters provide up to 48 days advance notice of a change in
time. The count remains at 00 or 50 at other times.
_________________________________________________________________________
LS = Leap second flag is set to "1" to indicate that a leap second is to be
added as 23:59:60 (UTC) on the last day of the current UTC month. The LS
flag will be reset to "0" starting with 23:59:60 (UTC). The flag will
remain on for the entire month before the second is added. Leap seconds
are added as needed at the end of any month. Usually June and/or December
are chosen.
The leap second flag will be set to a "2" to indicate that a leap second
is to be deleted at 23:59:58--00:00:00 on the last day of the current
month. (This latter provision is included per international recommendation
however it is not likely to be required in the near future.)
__________________________________________________________________________
DUT1 = Approximate difference between earth rotation time (UT1) and UTC, in
steps of 0.1 second. DUT1 = UT1 - UTC
___________________________________________________________________________
MJD = Modified Julian Date, often used to tag certain scientific data.
___________________________________________________________________________
The full time format is sent at 1200 baud, 8 bit, 1 stop, no parity.
The HH:MM:SS msADV time format at 300 baud is also 8 bit, 1 stop, no parity.
___________________________________________________________________________
Maximum on line time will be 55 seconds. If all lines are busy at any time,
the oldest call will be terminated if it has been on line more than 15
seconds, otherwise, the call that first reaches 15 seconds will be
terminated.
___________________________________________________________________________
Current time is valid at the "on-time" marker (OTM), either "*" or "#".
The nominal on-time marker (*) will be transmitted 45 ms early to account
for the 8 ms required to send 1 character at 1200 baud, plus an additional
7 ms for delay from NBS to the user, and approximately 30 ms "scrambler"
delay inherent in 1200 baud modems. If the caller echoes all characters,
NBS will measure the round trip delay and advance the on-time marker so
that the midpoint of the stop bit arrives at the user on time. The amount
of msADV will reflect the actual required advance in milliseconds and the
OTM will be a "#". The NBS system requires 4 consecutive delay
measurements which are consistent before switching from "*" to "#". If
the user has a 1200 baud modem with the same internal delay as that used
by NBS, then the "#" OTM should arrive at the user within +-2 ms of the
correct time. However, NBS has studied different brands of 1200 baud
modems and found internal delays from 24 ms to 40 ms and offsets of the
"#" OTM of +-10 ms. For many computer users, +-10 ms accuracy should be
more than adequate since many computer internal clocks can only be set
with granularity of 20 to 50 ms. In any case, the repeatability of the
offset for the "#" OTM should be within +-2 ms, if the dial-up path is
reciprocal and the user doesn't change the brand or model of modem used.
This should be true even if the dial-up path on one day is a land-line of
less than 40 ms (one way) and on the next day is a satellite link of 260
to 300 ms. In the rare event that the path is one way by satellite and
the other way by land line with a round trip measurement in the range of
90 to 260 ms, the OTM will remain a "*" indicating 45 ms advance. For the
user who wants the best possible accuracy at the OTM, NBS offers an
alternate 300 baud service with only HH:MM:SS MSADV and OTM. To use the
alternate service, simply call at 300 baud. Because of the simple FSK
modulation scheme used at 300 baud, all modems tested had the same delay
within about 1 ms.
___________________________________________________________________________
The full time format will be sent at 1200 baud, 8 bit, 1 stop, no parity.
The HH:MM:SS MSADV time format at 300 baud will also be 8b, 1s, np.
For user comments write:
NBS-ACTS
Time and Frequency Division
Mail Stop 524
325 Broadway
Boulder, CO 80303
Software for setting DOS compatable machines is available on a
360-kbyte diskette for $35.00 from:
NBS Office of Standard Reference Materials
B311-Chemistry Bldg, NBS, Gaithersburg, MD, 20899, (301) 975-6776
------- End of Forwarded Messagedavis@groucho.ucar.edu (Glenn P. Davis) (04/27/89)
chuck@trantor.harris-atd.com (Chuck Musciano) writes: >X-Sun-Spots-Digest: Volume 7, Issue 220, message 3 of 16 > >> Looking for a program that will dial up and read the time from National >> Bureau Standard and then set the local computer clock.. The way NCAR does it, I believe, is with a WWV Radio. This is looks like a spendy item. I don't have details, but the NSFNet hubs seem to have them in conjuction with their fuzzballs. Jeff Forys (forys@boulder.colorado.edu) wrote a program called 'settime' that allows one to Query the fuzzball to get the time. It takes transmission times into account and is 'pretty neat'. This actually works with any machine with the network time server configured in, we just query the fuzzball because it's hooked up to the WWV clock. Glenn P. Davis davis@unidata.ucar.edu UCAR / Unidata PO Box 3000 1685 38th St. Boulder, CO 80307-3000 Boulder, CO 80301 (303) 497 8643