freebsd-src/contrib/ntp/html/driver35.htm
2001-08-29 14:35:15 +00:00

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<title>Conrad parallel port radio clock</title>
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<h3>Conrad parallel port radio clock</h3>
<hr>
<h4>Synopsis</h4>
<p>Address: 127.127.35.<i>u</i><br>
Reference ID: <tt>PCF</tt><br>
Driver ID: <tt>PCF</tt><br>
Parallel Port: <tt>/dev/pcfclocks/<i>u</i></tt> or <tt>/dev/pcfclock<i>u</i></tt>
</p>
<h4>Description</h4>
<p>This driver supports the parallel port radio clock sold by
<a href="http://www.conrad-electronic.com/">Conrad Electronic</a> under
order numbers 967602 and 642002. This clock is put between a parallel
port and your printer. It receives the legal German time, which is
either CET or CEST, from the DCF77 transmitter and uses it to set its
internal quartz clock. The DCF77 transmitter is located near to
Frankfurt/Main and covers a radius of more than 1500 kilometers.
<p>The pcfclock device driver is required in order to use this
reference clock driver. Currently device drivers for
<a href="http://home.pages.de/~voegele/pcf.html">Linux</a> and
<a href="http://schumann.cx/pcfclock/">FreeBSD</a> are available.</p>
<p>This driver uses C library functions to convert the received
timecode to UTC and thus requires that the local timezone be CET or
CEST. If your server is not located in Central Europe you have to set
the environment variable TZ to CET before starting <tt>ntpd</tt>.
</p>
<h4>Monitor Data</h4>
<p>Each timecode is written to the <tt>clockstats</tt> file in the format
<tt>YYYY MM DD HH MI SS</tt>.</p>
<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 0.1725.</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>PCF</tt>.</dd>
<dt><tt>flag1 0 | 1</tt></dt>
<dd>Not used by this driver.</dd>
<dt><tt>flag2 0 | 1</tt></dt>
<dd>If set to 1, the radio clock's synchronisation status bit is
ignored, ie the timecode is used without a check.</dd>
<dt><tt>flag3 0 | 1</tt></dt>
<dd>Not used by this driver.</dd>
<dt><tt>flag4 0 | 1</tt></dt>
<dd>Not used by this driver.</dd>
</dl>
<hr>
<address>Andreas Voegele &lt;voegelas@users.sourceforge.net&gt;</address>
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