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diff --git a/contrib/ntp/html/driver4.htm b/contrib/ntp/html/driver4.htm deleted file mode 100644 index 4f3abd7..0000000 --- a/contrib/ntp/html/driver4.htm +++ /dev/null @@ -1,126 +0,0 @@ -<HTML><HEAD><TITLE> -Spectracom 8170 and Netclock/2 WWVB Receivers -</TITLE></HEAD><BODY><H3> -Spectracom 8170 and Netclock/2 WWVB Receivers -</H3><HR> - -<H4>Synopsis</H4> - -Address: 127.127.4.<I>u</I> -<BR>Reference ID: <TT>WWVB</TT> -<BR>Driver ID: <TT>WWVB_SPEC</TT> -<BR>Serial Port: <TT>/dev/wwvb<I>u</I></TT>; 9600 baud, 8-bits, no -parity -<BR>Features: <TT>tty_clk</TT> - -<H4>Description</H4> - -This driver supports all known Spectracom radio and satellite clocks, -including the Model 8170 and Netclock/2 WWVB Synchronized Clocks and the -Netclock/GPS GPS Master Clock. The claimed accuracy of the WWVB clocks -is 100 usec relative to the broadcast signal. These clocks have proven a -reliable source of time, except in some parts of the country with high -levels of conducted RF interference. WIth the GPS clock the claimed -accuracy is 130 ns. However, in most cases the actual accuracy is -limited by the precision of the timecode and the latencies of the serial -interface and operating system. - -<P>The DIPswitches on these clocks should be set to 24-hour display, -AUTO DST off, data format 0 or 2 (see below) and baud rate 9600. If this -clock is used as the source for the IRIG Audio Decoder -(<tt>refclock_irig.c</tt> in this distribution), set the DIPswitches for -AM IRIG output and IRIG format 1 (IRIG B with signature control). - -<P>There are two timecode formats used by these clocks. Format 0, which -is available with all clocks, and format 2, which is available with all -clocks except the original (unmodified) Model 8170. - -<P>Format 0 (22 ASCII printing characters): -<br><cr><lf>i ddd hh:mm:ss TZ=zz<cr><lf> - -<p>on-time = first <cr> -<br>i = synchronization flag (' ' = in synch, '?' = out synch) -<br>hh:mm:ss = hours, minutes, seconds</PRE> - -<p>The alarm condition is indicated by other than ' ' at <TT>i</TT>, -which occurs during initial synchronization and when received signal is -lost for about ten hours. - -<P>Format 2 (24 ASCII printing characters): -<br>lt;cr>lf>iqyy ddd hh:mm:ss.fff ld - -<p>on-time = <cr> -<br>i = synchronization flag (' ' = in synch, '?' = out synch) -<br>q = quality indicator (' ' = locked, 'A'...'D' = unlocked) -<br>yy = year (as broadcast) -<br>ddd = day of year -<br>hh:mm:ss.fff = hours, minutes, seconds, milliseconds</PRE> - -<p>The alarm condition is indicated by other than ' ' at <TT>i</TT>, -which occurs during initial synchronization and when received signal is -lost for about ten hours. The unlock condition is indicated by other -than ' ' at <TT>q</TT>. - -<P>The <TT>q</TT> is normally ' ' when the time error is less than 1 ms -and a character in the set <TT>A...D</TT> when the time error is less -than 10, 100, 500 and greater than 500 ms respectively. The <TT>l</TT> -is normally ' ', but is set to <TT>L</TT> early in the month of an -upcoming UTC leap second and reset to ' ' on the first day of the -following month. The <TT>d</TT> is set to <TT>S</TT> for standard time -<TT>S</TT>, <TT>I</TT> on the day preceding a switch to daylight time, -<TT>D</TT> for daylight time and <TT>O</TT> on the day preceding a -switch to standard time. The start bit of the first -<cr> is synchronized to the indicated time as returned. - -<P>This driver does not need to be told which format is in use - it -figures out which one from the length of the message. A three-stage -median filter is used to reduce jitter and provide a dispersion measure. -The driver makes no attempt to correct for the intrinsic jitter of the -radio itself, which is a known problem with the older radios. - -<H4>Monitor Data</H4> - -The driver writes each timecode as received to the <TT>clockstats</TT> -file. When enabled by the <TT>flag4</TT> fudge flag, a table of quality -data maintained internally by the Netclock/2 is retrieved and written to -the <TT>clockstats</TT> file when the first timecode message of a new -dayis received. - -<H4>Fudge Factors</H4> - -<DL> - -<DT><TT>time1 <I>time</I></TT></DT> -<DD>Specifies the time offset calibration factor, in seconds and -fraction, -with default 0.0.</DD> - -<DT><TT>time2 <I>time</I></TT></DT> -<DD>Not used by this driver.</DD> - -<DT><TT>stratum <I>number</I></TT></DT> -<DD>Specifies the driver stratum, in decimal from 0 to 15, with default -0.</DD> - -<DT><TT>refid <I>string</I></TT></DT> -<DD>Specifies the driver reference identifier, an ASCII string from one -to four characters, with default <TT>WWVB</TT>.</DD> - -<DT><TT>flag1 0 | 1</TT></DT> -<DD>Not used by this driver.</DD> - -<DT><TT>flag2 0 | 1</TT></DT> -<DD>Not used by this driver.</DD> - -<DT><TT>flag3 0 | 1</TT></DT> -<DD>Not used by this driver.</DD> - -<DT><TT>flag4 0 | 1</TT></DT> -<DD>Enable verbose <TT>clockstats</TT> recording if set.</DD> - -</DL> - -Additional Information - -<P><A HREF="refclock.htm">Reference Clock Drivers</A> -<HR><ADDRESS>David L. Mills (mills@udel.edu)</ADDRESS></BODY></HTML> |
