freebsd-nq/contrib/ntp/html/refclock.htm
1999-12-09 13:01:21 +00:00

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Reference Clock Drivers
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Reference Clock Drivers
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<IMG ALIGN=LEFT SRC=pic/tardisa.gif>From top:
<UL>
<LI>Austron 2100A GPS Receiver with LORAN-C assist</LI>
<LI>Austron 2000 LORAN-C Receiver></LI>
<LI>Spectracom 8170 WWVB Receiver</LI>
<LI>Hewlett Packard 5061A Cesium Beam Standard</LI>
</UL>
<br clear=left>
The Tardis
<hr>
<H4>Reference Clock Drivers</H4>
Support for most of the commonly available radio and modem clocks is
included in the default configuration of the NTP daemon for Unix
<TT>ntpd</TT>. Individual clocks can be activated by configuration file
commands, specifically the <TT>server</TT> and <TT>fudge</TT> commands
described in the <A HREF=ntpd.htm><TT>ntpd</TT> program manual
page</A>. The following discussion presents Information on how to select
and configure the device drivers in a running Unix system.
<P>Radio and modem clocks by convention have addresses in the form
127.127.<I>t.u</I>, where <I>t</I> is the clock type and <I>u</I> is a
unit number in the range 0-3 used to distinguish multiple instances of
clocks of the same type. Most of these clocks require support in the
form of a serial port or special bus peripheral, but some can work
directly from the audio codec found in some workstations. The particular
device is normally specified by adding a soft link
<TT>/dev/device<I>u</I></TT> to the particular hardware device involved,
where <I><TT>u</TT></I> correspond to the unit number above.
<P>Following is a list showing the type and title of each driver
currently implemented. The compile-time identifier for each is shown in
parentheses. Click on a selected type for specific description and
configuration documentation, including the clock address, reference ID,
driver ID, device name and speed, and features (line disciplines, etc.).
For those drivers without specific documentation, please contact the
author listed in the <A HREF=copyright.htm>copyright page</A>.
<P><A HREF=driver1.htm>Type 1</A> Undisciplined Local Clock
(<TT>LOCAL</TT>)
<BR><A HREF=driver2.htm>Type 2</A> Trak 8820 GPS Receiver
(<TT>GPS_TRAK</TT>)
<BR><A HREF=driver3.htm>Type 3</A> PSTI/Traconex 1020 WWV/WWVH
Receiver
(<TT>WWV_PST</TT>)
<BR><A HREF=driver4.htm>Type 4</A> Spectracom 8170 and Netclock/2 WWVB
Receivers (<TT>WWVB_SPEC</TT>)
<BR><A HREF=driver5.htm>Type 5</A> TrueTime GPS/GOES/OMEGA Receivers
(<TT>TRUETIME</TT>)
<BR><A HREF=driver6.htm>Type 6</A> IRIG Audio Decoder
(<TT>IRIG_AUDIO</TT>)
<BR><A HREF=driver7.htm>Type 7</A> CHU Audio/Modem Decoder
(<TT>CHU</TT>)
<BR><A HREF=driver8.htm>Type 8</A> Generic Reference Driver
(<TT>PARSE</TT>)
<BR><A HREF=driver9.htm>Type 9</A> Magnavox MX4200 GPS Receiver
(<TT>GPS_MX4200</TT>)
<BR><A HREF=driver10.htm>Type 10</A> Austron 2200A/2201A GPS Receivers
(<TT>GPS_AS2201</TT>)
<BR><A HREF=driver11.htm>Type 11</A> Arbiter 1088A/B GPS Receiver
(<TT>GPS_ARBITER</TT>)
<BR><A HREF=driver12.htm>Type 12</A> KSI/Odetics TPRO/S IRIG Interface
(<TT>IRIG_TPRO</TT>)
<BR>Type 13 Leitch CSD 5300 Master Clock Controller
(<TT>ATOM_LEITCH</TT>)
<BR>Type 14 EES M201 MSF Receiver (<TT>MSF_EES</TT>)
<BR><A HREF=driver5.htm>Type 15</A> * TrueTime generic receivers
<BR>Type 16 Bancomm GPS/IRIG Receiver (<TT>GPS_BANCOMM</TT>)
<BR>Type 17 Datum Precision Time System (<TT>GPS_DATUM</TT>)
<BR><A HREF=driver18.htm>Type 18</A> NIST Modem Time Service
(<TT>ACTS_NIST</TT>)
<BR><A HREF=driver19.htm>Type 19</A> Heath WWV/WWVH Receiver
(<TT>WWV_HEATH</TT>)
<BR><A HREF=driver20.htm>Type 20</A> Generic NMEA GPS Receiver
(<TT>NMEA</TT>)
<BR>Type 21 TrueTime GPS-VME Interface (<TT>GPS_VME</TT>)
<BR><A HREF=driver22.htm>Type 22</A> PPS Clock Discipline
(<TT>PPS</TT>)
<BR><A HREF=driver23.htm>Type 23</A> PTB Modem Time Service
(<TT>ACTS_PTB</TT>)
<BR><A HREF=driver24.htm>Type 24</A> USNO Modem Time Service
(<TT>ACTS_USNO</TT>)
<BR><A HREF=driver5.htm>Type 25</A> * TrueTime generic receivers
<BR><A HREF=driver26.htm>Type 26</A> Hewlett Packard 58503A GPS
Receiver
(<TT>GPS_HP</TT>)
<BR><A HREF=driver27.htm>Type 27</A> Arcron MSF Receiver
(<TT>MSF_ARCRON</TT>)
<BR><A HREF=driver28.htm>Type 28</A> Shared memory driver
(<TT>SHM</TT>)
<BR><A HREF=driver29.htm>Type 29</A> Trimble Navigation Palisade GPS (<TT>GPS_PALISADE</TT>)
<BR><A HREF=driver30.htm>Type 30 Motorola UT Oncore GPS
(<TT>GPS_ONCORE</TT>)
<BR>Type 31 Rockwell Jupiter GPS (<TT>GPS_JUPITER</TT>)
<BR><A HREF=driver34.htm>Type 34</A> Ultralink WWVB receivers
<P>* All TrueTime receivers are now supported by one driver, type 5.
Types
15 and 25 will be retained only for a limited time and may be reassigned
in future.
<P>Additional Information
<P><A HREF=prefer.htm>Mitigation Rules and the <TT>prefer</TT>
Keyword</A>
<BR><A HREF=rdebug.htm>Debugging Hints for Reference Clock Drivers</A>
<BR><A HREF=ldisc.htm>Line Disciplines and Streams Drivers</A>
<BR><A HREF=pps.htm>Pulse-per-second (PPS) Signal Interfacing</A>
<BR><A HREF=howto.htm>How To Write a Reference Clock Driver</A>
<BR><A HREF=index.htm>The Network Time Protocol (NTP)
Distribution&nbsp;</A>&nbsp;
<hr><a href=index.htm><img align=left src=pic/home.gif></a><address><a
href=mailto:mills@udel.edu> David L. Mills &lt;mills@udel.edu&gt;</a>
</address></a></body></html>