Re: Info needed on Spectracom 8171A clock... Help

From: Dennis (Dennis_The_Menace_at_no_spam.net)
Date: 08/14/04 

Date: Sat, 14 Aug 2004 07:35:42 -0500

In article <bec993c8.0408140413.530d0a4d@posting.google.com>,
shoppa@trailing-edge.com says...
>
>
>Dennis <Dennis_The_Menace@no_spam.net> wrote in message
news:<10hnmbgs2042aac@corp.supernews.com>...
>> --
>>
>> I have a Spectracom 8171A WWVB Synchronized clock.
>> Need a manual on this clock, or some good operating
>> information. Much appreciated.
>
>I believe that it uses the same protocols as the Spectracom
>8170, which is well documented in many places including the NTP
>source code. From refclock_wwvb.c:
>
> * This driver supports the Spectracom Model 8170 and Netclock/2 WWVB
> * Synchronized Clocks and the Netclock/GPS Master Clock. Both the WWVB
> * and GPS clocks have proven reliable sources of time; however, the
> * WWVB clocks have proven vulnerable to high ambient conductive RF
> * interference. The claimed accuracy of the WWVB clocks is 100 us
> * relative to the broadcast signal, while the claimed accuracy of the
> * GPS clock is 50 ns; however, in most cases the actual accuracy is
> * limited by the resolution of the timecode and the latencies of the
> * serial interface and operating system.
> *
> * The WWVB and GPS clocks should be configured for 24-hour display,
> * AUTO DST off, time zone 0 (UTC), data format 0 or 2 (see below) and
> * baud rate 9600. If the clock is to used as the source for the IRIG
> * Audio Decoder (refclock_irig.c in this distribution), it should be
> * configured for AM IRIG output and IRIG format 1 (IRIG B with
> * signature control). The GPS clock can be configured either to respond
> * to a 'T' poll character or left running continuously.
> *
> * There are two timecode formats used by these clocks. Format 0, which
> * is available with both the Netclock/2 and 8170, and format 2, which
> * is available only with the Netclock/2, specially modified 8170 and
> * GPS.
> *
> * Format 0 (22 ASCII printing characters):
> *
> * <cr><lf>i ddd hh:mm:ss TZ=zz<cr><lf>
> *
> * on-time = first <cr>
> * hh:mm:ss = hours, minutes, seconds
> * i = synchronization flag (' ' = in synch, '?' = out of synch)
> *
> * The alarm condition is indicated by other than ' ' at a, which occurs
> * during initial synchronization and when received signal is lost for
> * about ten hours.
> *
> * Format 2 (24 ASCII printing characters):
> *
> * <cr><lf>iqyy ddd hh:mm:ss.fff ld
> *
> * on-time = <cr>
> * i = synchronization flag (' ' = in synch, '?' = out of synch)
> * q = quality indicator (' ' = locked, 'A'...'D' = unlocked)
> * yy = year (as broadcast)
> * ddd = day of year
> * hh:mm:ss.fff = hours, minutes, seconds, milliseconds
> *
> * The alarm condition is indicated by other than ' ' at a, which occurs
> * during initial synchronization and when received signal is lost for
> * about ten hours. The unlock condition is indicated by other than ' '
> * at q.
> *
> * The q is normally ' ' when the time error is less than 1 ms and a
> * character in the set 'A'...'D' when the time error is less than 10,
> * 100, 500 and greater than 500 ms respectively. The l is normally ' ',
> * but is set to 'L' early in the month of an upcoming UTC leap second
> * and reset to ' ' on the first day of the following month. The d is
> * set to 'S' for standard time 'I' on the day preceding a switch to
> * daylight time, 'D' for daylight time and 'O' on the day preceding a
> * switch to standard time. The start bit of the first <cr> is
> * synchronized to the indicated time as returned.
>
>Tim.

Tim,

thank you for your response. This clock does not receieve the WWVB signal
directly, instead it is inputed via a WWVB receiver. The receiver that
can be used are the 8160,8161, 8164, and 8165. At this point I guess I need
one of those receivers.

Dennis 

--

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