<br><h4>Naming a Device</h4>
<p>
- The <i>GPSD</i> driver uses the same device name as the NMEA
- driver, namely <tt>/dev/gps<i>u</i></tt>. There is a simple
- reason for that: While the NMEA driver and the <i>GPSD</i>
- driver can be active at the same time <b>for different
- devices</b>, they cannot access the same device at a
+ By default, the <i>GPSD</i> driver uses the same device name as
+ the NMEA driver, namely <tt>/dev/gps<i>u</i></tt>. There is a
+ simple reason for that: While the NMEA driver and
+ the <i>GPSD</i> driver can be active at the same time <b>for
+ different devices</b>, they cannot access the same device at a
time. Having the same name helps on that. It also eases
migration from using NMEA directly to using <i>GPSD</i>, as no
new links etc need to be created.
identification. This makes the migration from the built-in NMEA
driver a bit easier.
</p>
+ <p>
+ The driver also honors <tt>device</tt> statements for
+ the <tt>timedata</tt> channel. (PPS is handled
+ inside <i>GPSD</i>, so there's no need for that.) This permits a
+ more natural way to specify the link between <i>GPSD</i>
+ and <i>NTPD</i>: Simply name the device as it was given
+ to <i>GPSD</i>.
+ </p>
<p><b>Note:</b> <i>GPSD</i> (as of version 3.10) cannot use kernel
- mode PPS on devices that are hot-plugged. This would require to
- attach the PPS line discipline to the character special file,
- which is not possible when running with root privileges already
- dropped. This is not likely to change in the future.
+ mode PPS on devices that are hot-plugged or activated on demand.
+ This is not likely to change in the future. Have a look
+ at <i>GPSD</i>'s <tt>-n</tt> (<i>nowait</i>) option.
</p>
<!-- --------------------------------------------------------- -->
120s. Then it reverts to STI-only operation until the PPS
is stable again for 40s, when strict mode is engaged
again.
- <br><br><b>Important Notice: This is an expiremental
+ <br><br><b>Important Notice: This is an experimental
feature!</b><br> Switching between strict and STI-only
mode will cause changes in offset and jitter. Use this
mode only if STI-only works fairly well with your setup,
primary clock unit (u mod 128). A secondary unit processes only
the PPS data from <i>GPSD</i> and needs the corresponding master
unit to work<a href="#fn1" name="fn1bl"><sup>1</sup></a>. Use
- the 'noselect' keyword on the primary unit if you are not
+ the '<tt>noselect</tt>' keyword on the primary unit if you are not
interested in its data.
</p><p>The secondary unit employs the usual precautions before
feeding clock samples:</p>
only be used if the GPS receiver can be trusted for the quality
of its PPS signal<a href="fn2"
name="fn2bl"><sup>2</sup></a>. The PPS flag gets cleared if no
- PPS records can be aquired for some time. The unit also flushes
+ PPS records can be acquired for some time. The unit also flushes
the sample buffer at this point to avoid the use of stale PPS
data.</p>
<p><b>Attention:</b> This unit uses its own PPS fudge value