94 lines
3.1 KiB
HTML
94 lines
3.1 KiB
HTML
<!-- $NetBSD: driver9.html,v 1.1 1998/12/30 20:20:35 mcr Exp $ -->
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<!DOCTYPE HTML PUBLIC "-//IETF//DTD HTML Strict//EN">
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<html><head><title>
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Magnavox MX4200 GPS Receiver
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</title></head><body><h3>
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Magnavox MX4200 GPS Receiver
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</h3><hr>
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<p><h4>Synopsis</h4>
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<p>Address: 127.127.9.<var>u</var>
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<br>Reference ID: GPS
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<br>Driver ID: GPS-MX4200
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<br>Serial Port: <code>/dev/gps<var>u</var></code>; 4800 baud, 8-bits,
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no parity
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<br>Features: <code>ppsclock</code> (required)
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<p><h4>Description</h4>
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<p>This driver supports the Magnavox MX 4200 Navigation Receiver adapted
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to precision timing applications. It requires the <code>ppsclock</code>
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line discipline or streams module described in the <a
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href="ldisc.html">Line Disciplines and Streams Drivers</a> page. It also
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requires a gadget box and 1-PPS level converter, such as described in
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the <a href="pps.html">Pulse-per-second (PPS) Signal Interfacing</a>
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page.
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<p>This driver supports all compatible receivers such as the 6-channel
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MX 4200, MX 4200D, and the 12-channel MX 9212, MX 9012R, MX 9112.
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<p><h4>Operating Modes</h4>
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<p>This driver supports two modes of operation, static and mobile,
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controlled by clock flag 2.
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<p>In static mode (the default) the driver assumes that the GPS antenna
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is in a fixed location. The receiver is initially placed in a "Static,
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3D Nav" mode, where latitude, longitude, elevation and time are
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calculated for a fixed station. A DOP-weighted running average position
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is calculated from this data. After 24 hours, the receiver is placed
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into a "Known Position" mode, initialized with the calculated position,
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and then solves only for time. The position averaging algorithm does
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not take into account boundary conditions, so this mode of operation
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very near the international date line or the poles is not recommended.
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<p>In mobile mode, the driver assumes the GPS antenna is mounted on
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a moving platform such as a car, ship, or aircraft. The receiver is
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placed in "Dynamic, 3D Nav" mode and solves for position, altitude and
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time while moving. No position averaging is performed.
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<p><h4>Monitor Data</h4>
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<p>The driver writes each timecode as received to the
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<code>clockstats</code> file.
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<p><h4>Fudge Factors</h4>
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<dl>
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<dt><code>time1 <i>time</i></code>
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<dd>Specifies the time offset calibration factor, in seconds and
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fraction, with default 0.0.
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<p><dt><code>time2 <i>time</i></code>
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<dd>Not used by this driver.
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<p><dt><code>stratum <i>number</i></code>
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<dd>Specifies the driver stratum, in decimal from 0 to 15, with default
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0.
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<p><dt><code>refid <i>string</i></code>
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<dd>Specifies the driver reference identifier, an ASCII string from one
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to four characters, with default <code>GPS</code>.
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<p><dt><code>flag1 0 | 1</code>
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<dd>Not used by this driver.
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<p><dt><code>flag2 0 | 1</code>
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<dd>Assume GPS receiver is on a mobile platform if set.
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<p><dt><code>flag3 0 | 1</code>
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<dd>Not used by this driver.
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<p><dt><code>flag4 0 | 1</code>
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<dd>Not used by this driver.
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</dl>
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<p>Additional Information
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<p><a href="refclock.html"> Reference Clock Drivers</a>
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<hr><address>David L. Mills (mills@udel.edu)</address></body></html>
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