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Info needed on Spectracom 8171A clock... Help

Discussion in 'Misc Electronics' started by Dennis, Aug 12, 2004.

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  1. Dennis

    Dennis Guest

    --

    I have a Spectracom 8171A WWVB Synchronized clock.
    Need a manual on this clock, or some good operating
    information. Much appreciated.

    TIA,

    Dennis
     
  2. Tim Shoppa

    Tim Shoppa Guest

    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.
     
  3. Dennis

    Dennis Guest

    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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