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| author | roberto <roberto@FreeBSD.org> | 2004-07-20 15:19:51 +0000 |
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| committer | roberto <roberto@FreeBSD.org> | 2004-07-20 15:19:51 +0000 |
| commit | 52f0477edd81105d995864898a64a601b67d66d8 (patch) | |
| tree | 3528c92623def79de13bd8f8caaa5639362dd64b /contrib/ntp/html/driver8.htm | |
| parent | 4155ac9f07c2f1986843c07b428ac66e6f11ffe0 (diff) | |
| download | FreeBSD-src-52f0477edd81105d995864898a64a601b67d66d8.zip FreeBSD-src-52f0477edd81105d995864898a64a601b67d66d8.tar.gz | |
Merge conflicts.
Lots of added files, some removed and quite a large number of renames :(
Diffstat (limited to 'contrib/ntp/html/driver8.htm')
| -rw-r--r-- | contrib/ntp/html/driver8.htm | 353 |
1 files changed, 0 insertions, 353 deletions
diff --git a/contrib/ntp/html/driver8.htm b/contrib/ntp/html/driver8.htm deleted file mode 100644 index 17ab6c3..0000000 --- a/contrib/ntp/html/driver8.htm +++ /dev/null @@ -1,353 +0,0 @@ -<HTML><HEAD><TITLE> -Generic Reference Driver -</TITLE></HEAD><BODY><H3> -Generic Reference Driver -</H3><HR> - -<H4>Synopsis</H4> - -Address: 127.127.8.<I>u</I> -<BR>Reference ID: <TT>PARSE</TT> -<BR>Driver ID: <TT>GENERIC</TT> -<BR>Serial Port: <TT>/dev/refclock-<I>u</I></TT>; TTY mode according to -clock type - -<H4>Description</H4> - -The timecode of these receivers is sampled via a STREAMS module in the -kernel (The STREAMS module has been designed for use with SUN Systems -under SunOS 4.1.x or Solaris 2.3 - 2.6. It can be linked directly into -the kernel or loaded via the loadable driver mechanism). This STREAMS -module can be adapted to be able to convert different time code formats. -If the daemon is compiled without the STREAM definition synchronization -will work without the Sun streams module, though accuracy is -significantly degraded. This feature allows to use PARSE also on non Sun -machines. - -<P>The actual receiver status is mapped into various synchronization -states generally used by receivers. The STREAMS module is configured to -interpret the time codes of DCF C51, PZF535, PZF509, GPS166, Trimble SV6 -GPS, ELV DCF7000, Schmid, Wharton 400A and low cost receivers (see list -below). - -<P>The reference clock support in ntp contains the necessary -configuration tables for those receivers. In addition to supporting -several different clock types and 4 devices, the generation a a PPS -signal is also provided as an configuration option. The PPS -configuration option uses the receiver generated time stamps for feeding -the PPS loopfilter control for much finer clock synchronization. - -<P>CAUTION: The PPS configuration option is different from the hardware -PPS signal, which is also supported (see below), as it controls the way -ntpd is synchronized to the reference clock, while the hardware PPS -signal controls the way time offsets are determined. - -<P>The use of the PPS option requires receivers with an accuracy of -better than 1ms. - -<P>Fudge factors - -<P>Only two fudge factors are utilized. The time1 fudge factor defines -the phase offset of the synchronization character to the actual time. On -the availability of PPS information the time2 fudge factor defines the -skew between the PPS time stamp and the receiver timestamp of the PPS -signal. This parameter is usually zero, as usually the PPS signal is -believed in time and OS delays should be corrected in the machine -specific section of the kernel driver. time2 needs only be set when the -actual PPS signal is delayed for some reason. The flag1 enables input -filtering. This a median filter with continuous sampling. The flag2 -selects averaging of the samples remaining after the filtering. Leap -second-handling is controlled with the flag3. When set a leap second -will be deleted on receipt of a leap second indication from the -receiver. Otherwise the leap second will be added, (which is the -default). flag3 should never be set. PPS handling is enabled by adding -128 to the mode parameter in the server/peer command. - -<P>ntpq (8) -<P>timecode variable - -<P>The ntpq program can read clock variables command list several -variables. -These hold the following information: refclock_time is the local time -with -the offset to UTC (format HHMM). The currently active receiver flags are -listed in refclock_status. Additional feature flags of the receiver are -optionally listed in parentheses. The actual time code is listed in -timecode. -A qualification of the decoded time code format is following in -refclock_format. The last piece of information is the overall running -time and the accumulated times for the clock event states in -refclock_states. When PPS information is present additional variable are -available. refclock_ppstime lists then the PPS timestamp and -refclock_ppsskew lists the difference between RS232 -derived timestamp and the PPS timestamp. - -<P>Currently, eighteen clock types (devices /dev/refclock-0 - -/dev/refclock-3) are supported by the PARSE driver. -<BR>A note on the implementations: -<UL><li>These implementations where mainly done <B><I>WITHOUT</I></B> -actual access to the hardware. Thus not all implementations provide full -support. The development was done with the help of many souls who had -the hardware and where so kind to borrow me their time an patience -during the development and debugging cycle. Thus for continued support -and quality direct access to the receivers is a big help. Nevertheless i -am not prepared to buy these reference clocks - donations to <A -HREF="http://www4.informatik.uni-erlangen.de/~kardel">me</A> -(<A HREF="mailto: kardel@acm.org">kardel@acm.org</A>) are welcome as -long as they work within Europe 8-). - -<P>Verified implementations are: -<UL> -<LI> -RAWDCF variants - -<p>These variants are tested for the decoding with my own homegrown -receivers. Interfacing with specific commercial products may involve -some fiddeling with cables. Especially commericial RAWDCF receivers have -a seemingly unlimited number of ways to draw power from the RS232 port -and to encode the DCF77 datastream. You are mainly on your own here -unless i have a sample of the receiver. -<LI> -<A HREF="http://www.meinberg.de">Meinberg clocks</A> - -<p>These implementations are verified by the Meinberg people themselves -and i have access to one of these clocks.</UL> -</UL> -The pictures below refer to the respective clock and where taken from -the vendors web pages. They are linked to the respective vendors. -<UL> -<LI> -<B><TT>server 127.127.8.0-3 mode 0</TT></B> - -<p><B><TT><A HREF="http://www.meinberg.de">Meinberg </A>PZF535/<A -HREF="http://www.meinberg.de/english/products/pzf509.htm">PZF509 receiver</A> (FM -demodulation/TCXO / 50us)</TT></B> -<BR> -<LI> -<B><TT>server 127.127.8.0-3 mode 1</TT></B> - -<p><B><TT><A HREF="http://www.meinberg.de">Meinberg </A> PZF535/<A -HREF="http://www.meinberg.de/english/products/pzf509.htm">PZF509 -receiver</A> (FM demodulation/OCXO / 50us)</TT></B> -<BR><A HREF="http://www.meinberg.de/english/products/pzf509.htm"><IMG -SRC="pic/pzf509.jpg" ALT="BILD PZF509" HEIGHT=300 WIDTH=260 -ALIGN=TEXTTOP></A> -<BR> -<LI> -<B><TT>server 127.127.8.0-3 mode 2</TT></B> - -<p><B><TT><A HREF="http://www.meinberg.de">Meinberg </A> DCF U/A -31/<A HREF="http://www.meinberg.de/english/products/c51.htm">DCF C51 receiver</A> -(AM demodulation / 4ms)</TT></B> -<BR><A HREF="http://www.meinberg.de/english/products/c51.htm"><IMG -SRC="pic/c51.jpg" ALT="BILD C51" HEIGHT=180 WIDTH=330 ALIGN=TEXTTOP></A> -<BR> -<LI> -<B><TT>server 127.127.8.0-3 mode 3</TT></B> - -<p><B><TT><A HREF="http://www.elv.de">ELV</A> DCF7000 (sloppy AM -demodulation -/ 50ms)</TT></B> -<BR> -<LI> -<B><TT>server 127.127.8.0-3 mode 4</TT></B> - -<p><B><TT>Walter Schmid DCF receiver Kit (AM demodulation / -1ms)</TT></B> -<BR> -<LI> -<B><TT>server 127.127.8.0-3 mode 5</TT></B> - -<p><B><TT>RAW DCF77 100/200ms pulses (Conrad DCF77 receiver module / -5ms)</TT></B> -<BR> -<LI> -<B><TT>server 127.127.8.0-3 mode 6</TT></B> - -<p><B><TT>RAW DCF77 100/200ms pulses (TimeBrick DCF77 receiver module -/ 5ms)</TT></B> -<BR> -<LI> -<B><TT>server 127.127.8.0-3 mode 7</TT></B> - -<p><B><TT><A HREF="http://www.meinberg.de">Meinberg </A> <A -HREF="http://www.meinberg.de/english/products/gps167.htm">GPS166/GPS167 -receiver</A> (GPS / <<1us)</TT></B> -<BR><A HREF="http://www.meinberg.de/english/products/gps167.htm"><IMG -SRC="pic/gps167.jpg" ALT="BILD GPS167" HEIGHT=300 WIDTH=280 -ALIGN=TEXTTOP></A> -<BR> -<LI> -<B><TT>server 127.127.8.0-3 mode 8</TT></B> -<p><B><TT><A HREF="http://www.igel.de">IGEL</A> <A -HREF="http://www.igel.de/eigelmn.htm">clock</A></TT></B> -<BR><A HREF="http://www.igel.de/eigelmn.htm"><IMG SRC="pic/igclock.gif" -HEIGHT=174 WIDTH=200></A> -<BR> -<LI> -<B><TT>server 127.127.8.0-3 mode 9</TT></B> - -<p><B><TT><A HREF="http://www.trimble.com">Trimble</A> <A -HREF="http://www.trimble.com/cgi/omprod.cgi/pd_om011.htm">SVeeSix -GPS receiver</A>TAIP protocol (GPS / <<1us)</TT></B> -<BR> -<LI> -<B><TT>server 127.127.8.0-3 mode 10</TT></B> - -<p><B><TT><A HREF="http://www.trimble.com">Trimble</A> <A -HREF="http://www.trimble.com/cgi/omprod.cgi/pd_om011.htm">SVeeSix -GPS receiver</A> TSIP protocol (GPS / <<1us) (no kernel support -yet)</TT></B> -<BR><A HREF="http://www.trimble.com/cgi/omprod.cgi/pd_om011.htm"><IMG -SRC="pic/pd_om011.gif" ALT="SVeeSix-CM3" BORDER=0 HEIGHT=100 WIDTH=420 -ALIGN=TEXTTOP></A> -<BR><A HREF="http://www.trimble.com/cgi/omprod.cgi/pd_om006.htm"><IMG -SRC="pic/pd_om006.gif" ALT="Lassen-SK8" BORDER=0 HEIGHT=100 -WIDTH=420></A> -<BR> -<LI> -<B><TT>server 127.127.8.0-3 mode 11</TT></B> - -<p><B><TT>Radiocode Clocks Ltd RCC 8000 Intelligent Off-Air Master -Clock -support </TT></B> -<BR> -<LI> -<B><TT>server 127.127.8.0-3 mode 12</TT></B> - -<p><B><TT><A HREF="http://www.hopf-time.com">HOPF</A> <A -HREF="http://www.hopf-time.com/kart6021.htm">Funkuhr -6021</A></TT></B> -<BR><A HREF="http://www.hopf-time.com/engl/kart6021.htm"><IMG -SRC="pic/fg6021.gif" ALT="DCF77-Interface Board" HEIGHT=207 WIDTH=238 -ALIGN=TEXTTOP></A> -<BR> -<LI> -<B><TT>server 127.127.8.0-3 mode 13</TT></B> - -<p><B><TT>Diem's Computime Radio Clock</TT></B> -<BR> -<LI> -<B><TT>server 127.127.8.0-3 mode 14</TT></B> - -<p><B><TT>RAWDCF receiver (DTR=high/RTS=low)</TT></B> - -<LI> -<B><TT>server 127.127.8.0-3 mode 15</TT></B> - -<p><B><TT>WHARTON 400A Series Clocks with a 404.2 Serial -Interface</TT></B> -<LI> -<B><TT>server 127.127.8.0-3 mode 16</TT></B> - -<p><B><TT>RAWDCF receiver (DTR=low/RTS=high) -</TT></B> -<LI> -<B><TT>server 127.127.8.0-3 mode 17</TT></B> - -<p><B><TT>VARITEXT Receiver (MSF) -</TT></B> -</UL> -<p> -Actual data formats and set-up requirements of the various clocks can be -found in <A HREF="parsedata.htm">NTP PARSE clock data formats</A>. - -<P>The reference clock support carefully monitors the state transitions -of the receiver. All state changes and exceptional events such as loss -of time code transmission are logged via the syslog facility. Every hour -a summary of the accumulated times for the clock states is listed via -syslog. - -<P>PPS support is only available when the receiver is completely -synchronized. The receiver is believed to deliver correct time for an -additional period of time after losing synchronizations, unless a -disruption in time code transmission is detected (possible power loss). -The trust period is dependent on the receiver oscillator and thus a -function of clock type. This is one of the parameters in the clockinfo -field of the reference clock implementation. This parameter cannot be -configured by ntpdc. - -<P>In addition to the PPS loopfilter control a true PPS hardware signal -can be applied on Sun Sparc stations via the CPU serial ports on the CD -pin. This signal is automatically detected and will be used for offset -calculation. The input signal must be the time mark for the following -time code. (The edge sensitivity can be selected - look into the -appropriate kernel/parsestreams.c for details). Meinberg receivers can -be connected by feeding the PPS pulse of the receiver via a 1488 level -converter to Pin 8 (CD) of a Sun serial zs-port. To select PPS support -the STREAMS driver for PARSE must be loaded and the mode parameter ist -the mode value of above plus 128. If 128 is not added to the mode value -PPS will be detected to be available but it will not be used. For PPS to -be used you MUST add 128 to the mode parameter. - -<P>For the Meinberg GPS166/GPS167 receiver is also a special firmware -release available (Uni-Erlangen). This release should be used for proper -operation. - -<P>The raw DCF77 pulses can be fed via a level converter directly into -Pin 3 (Rx) of the Sun. The telegrams will be decoded an used for -synchronization. AM DCF77 receivers are running as low as $25. The -accuracy is dependent on the receiver and is somewhere between 2ms -(expensive) to 10ms (cheap). Upon bad signal reception of DCF77 -synchronizations will cease as no backup oscillator is available as -usually found in other reference clock receivers. So it is important to -have a good place for the DCF77 antenna. For transmitter shutdowns you -are out of luck unless you have other NTP servers with alternate time -sources available. - -<H4>Monitor Data</H4> - -Clock states statistics are written hourly the the syslog service. -Online information can be found by examining the clock variable via the -ntpq cv command. - -<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 depending on clock type.</DD> - -<DT><TT>time2 <I>time</I></TT></DT> -<DD>Specifies the offset if the PPS signal to the actual time. (PPS fine -tuning).</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 according to current clock type.</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>delete next leap second instead of adding it.</DD> - -<DT> -<TT>flag4 0 | 1</TT></DT> -<DD>Delete next leap second instead of adding it - flag will be re- -defined soon - so don't use it. Statistics are provided by more common -means (syslog, clock variable via ntpq)</DD> - -</DL> - -<H4>Making your own PARSE clocks</H4> - -The parse clock mechanismis deviated from the way other ntp reference -clocks work. For a short description how to build parse reference clocks -see <A HREF="parsenew.htm">making PARSE clocks</A> - -<P>Additional Information - -<P><A HREF="refclock.htm">Reference Clock Drivers</A> - -<hr><a href=index.htm><img align=left src=pic/home.gif></a><address><a -href="mailto:mills@udel.edu"> David L. Mills <mills@udel.edu></a> -</address></body></html> |
