driver8.html revision 182007
190731Sjhay<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"> 290731Sjhay 390731Sjhay<html> 490731Sjhay 590731Sjhay <head> 690731Sjhay <meta http-equiv="content-type" content="text/html;charset=iso-8859-1"> 790731Sjhay <title>Generic Reference Driver</title> 890731Sjhay <link href="scripts/style.css" type="text/css" rel="stylesheet"> 990731Sjhay </head> 1090731Sjhay 1190731Sjhay <body> 1290731Sjhay <h3>Generic Reference Driver</h3> 1390731Sjhay <hr> 1490731Sjhay <h4>Synopsis</h4> 1590731Sjhay Address: 127.127.8.<i>u</i><br> 1690731Sjhay Reference ID: <tt>PARSE</tt><br> 1790731Sjhay Driver ID: <tt>GENERIC</tt><br> 1890731Sjhay Serial Port: <tt>/dev/refclock-<i>u</i></tt>; TTY mode according to clock type<br> 1990731Sjhay PPS device: <tt>/dev/refclockpps-<i>u</i></tt>; alternate PPS device (if not available via the serial port) 2090731Sjhay <h4>Description</h4> 2190731Sjhay The PARSE driver supports 20 different clock types/configurations. PARSE is actually a multi-clock driver.<br> 2290731Sjhay <br> 2390731Sjhay <p>The actual receiver status is mapped into various synchronization states generally used by receivers. The driver is configured to interpret the time codes of Meinberg DCF77 AM receivers, DCF77 FM receivers, Meinberg GPS16x/17x receivers, Trimble SV6 GPS, ELV DCF7000, Schmid, Wharton 400A and low cost receivers (see <a href="#clocklist">list below</a>).</p> 2490731Sjhay <p>The reference clock support in NTP contains the necessary configuration tables for those receivers. In addition to supporting several different clock types and up to 4 devices, the processing of a PPS signal is also provided as a configuration option. The PPS configuration option uses the receiver-generated time stamps for feeding the PPS loopfilter control for much finer clock synchronization.</p> 2590731Sjhay <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> 2690731Sjhay <p>The use of the PPS option requires receivers with an accuracy of better than 1ms.</p> 2790731Sjhay <h4>Timecode variables listed by ntpq (8)</h4> 2890731Sjhay <p>The ntpq program can read and display several clock variables. These hold the following information:</p> 2990731Sjhay <dl> 3090731Sjhay <dt><tt>refclock_format</tt></dt> 3190731Sjhay <dd>A qualification of the decoded time code format.</dd> 3290731Sjhay <dt><tt>refclock_states</tt></dt> 3390731Sjhay <dd>The overall running time and the accumulated times for the clock event states.</dd> 3490731Sjhay <dt><tt>refclock_status</tt></dt> 3590731Sjhay <dd>Lists the currently active receiver flags. Additional feature flags for the receiver are optionally listed in parentheses.</dd> 3690731Sjhay <dt><tt>refclock_time</tt></dt> 3790731Sjhay <dd>The local time with the offset to UTC (format HHMM).</dd> 3890731Sjhay <dt><tt>timecode</tt></dt> 3990731Sjhay <dd>The actual time code.</dd> 4090731Sjhay </dl> 4190731Sjhay <p>If PPS information is present, additional variables are available:</p> 4290731Sjhay <dl> 4390731Sjhay <dt><tt>refclock_ppsskew</tt></dt> 4490731Sjhay <dd>The difference between the RS-232-derived timestamp and the PPS timestamp.</dd> 4590731Sjhay <dt><tt>refclock_ppstime</tt></dt> 4690731Sjhay <dd>The PPS timestamp.</dd> 4790731Sjhay </dl> 4890731Sjhay <h4>Supported Devices</h4> 4990731Sjhay <p>Currently, nineteen clock types (devices /dev/refclock-0 - /dev/refclock-3) are supported by the PARSE driver.<br> 5090731Sjhay A note on the implementations:</p> 5190731Sjhay <ul> 5290731Sjhay <li>These implementations were mainly done without actual access to the hardware, thus not all implementations provide full support. The development was done with the help of many kind souls who had the hardware and kindly lent me their time and 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="mailto:kardel <AT> ntp.org">kardel <AT> ntp.org</a>) are welcome as long as they work within Europe 8-). 5390731Sjhay <p>Verified implementations are:</p> 5490731Sjhay <ul> 5590731Sjhay <li>RAWDCF variants 5690731Sjhay <p>These variants have been tested for correct decoding with my own homegrown receivers. Interfacing with specific commercial products may involve some fiddling with cables. In particular, commercial RAWDCF receivers have a seemingly unlimited number of ways to draw power from the RS-232 port and to encode the DCF77 datastream. You are mainly on your own here unless I have a sample of the receiver.</p> 5790731Sjhay <li><a href="http://www.meinberg.de">Meinberg clocks</a> 5890731Sjhay <p>These implementations have been verified by the Meinberg people themselves and I have access to one of these clocks.</p> 5990731Sjhay </ul> 6090731Sjhay </ul> 6190731Sjhay <p>The pictures below have been taken from and are linked to the vendors' web pages.</p> 6290731Sjhay <a name="clocklist"></a> 6390731Sjhay <ul> 6490731Sjhay <li><b><tt>server 127.127.8.0-3 mode 0</tt></b> 6590731Sjhay <p><b><tt><a href="http://www.meinberg.de">Meinberg</a> <a href="http://www.meinberg.de/english/products/timesource.htm#dcf---freq_sync">PZF5xx receiver family</a> (FM demodulation/TCXO / 50μs)</tt></b><br> 6690731Sjhay <br></p> 6790731Sjhay 6890731Sjhay <li><b><tt>server 127.127.8.0-3 mode 1</tt></b> 6990731Sjhay <p><b><tt><a href="http://www.meinberg.de">Meinberg</a> <a href="http://www.meinberg.de/english/products/timesource.htm#dcf---freq_sync">PZF5xx receiver family</a> (FM demodulation/OCXO / 50μs)</tt></b><br> 7090731Sjhay <a href="http://www.meinberg.de/english/products/pzf-eurocard.htm"><img src="../pic/pzf511.jpg" alt="Image PZF511" height="300" width="260" align="top" border="0"></a><br> 7190731Sjhay <br></p> 7290731Sjhay 7390731Sjhay <li><a name="mode2"></a><b><tt>server 127.127.8.0-3 mode 2</tt></b> 7490731Sjhay <p><b><tt><a href="http://www.meinberg.de">Meinberg</a> <a href="http://www.meinberg.de/english/products/c51.htm">DCF C51 receiver and similar</a> (AM demodulation / 4ms)</tt></b><br> 7590731Sjhay <a href="http://www.meinberg.de/english/products/c51.htm"><img src="../pic/c51.jpg" alt="Image C51" height="239" width="330" align="top" border="0"></a><br> 7690731Sjhay </p> 7790731Sjhay <p>This mode expects the Meinberg standard time string format with 9600/7E2.</p> 7890731Sjhay <p><b>Note:</b> mode 2 must also be used for <a href="http://www.meinberg.de/english/products/formfactor.htm#slot_card">Meinberg PCI cards</a> under Linux, e.g. <a href="http://www.meinberg.de/english/products/gps-pcicard.htm">the GPS PCI card</a> or <a href="http://www.meinberg.de/english/products/dcf-pcicard.htm">the DCF77 PCI card</a>. Please note the <a href="http://www.meinberg.de/english/sw/#linux">Meinberg Linux driver</a> must be installed. That driver emulates a refclock device in order to allow ntpd to access those cards. For details, please refer to the README file that comes with the Meinberg driver package.<br> 7990731Sjhay <br></p> 8090731Sjhay 8190731Sjhay <li><b><tt>server 127.127.8.0-3 mode 3</tt></b> 8290731Sjhay <p><b><tt><a href="http://www.elv.de">ELV</a> DCF7000 (sloppy AM demodulation / 50ms)</tt></b><br> 8390731Sjhay <br></p> 84102751Sjmallett 85102751Sjmallett <li><b><tt>server 127.127.8.0-3 mode 4</tt></b> 8690731Sjhay <p><b><tt>Walter Schmid DCF receiver Kit (AM demodulation / 1ms)</tt></b><br> 8790731Sjhay <br></p> 8890731Sjhay 8990731Sjhay <li><b><tt>server 127.127.8.0-3 mode 5</tt></b> 9090731Sjhay <p><b><tt>RAW DCF77 100/200ms pulses (Conrad DCF77 receiver module / 5ms)</tt></b><br> 9190731Sjhay <br></p> 9290731Sjhay 9390731Sjhay <li><b><tt>server 127.127.8.0-3 mode 6</tt></b> 9490731Sjhay <p><b><tt>RAW DCF77 100/200ms pulses (TimeBrick DCF77 receiver module / 5ms)</tt></b><br> 9590731Sjhay <br></p> 9690731Sjhay 9790731Sjhay <li><b><tt>server 127.127.8.0-3 mode 7</tt></b> 9890731Sjhay <p><b><tt><a href="http://www.meinberg.de">Meinberg</a> <a href="http://www.meinberg.de/english/products/timesource.htm#gps---freq_sync">GPS16x/GPS17x receivers</a> (GPS / <<1μs)</tt></b><br> 99102714Sphk <a href="http://www.meinberg.de/english/products/gps-eurocard.htm"><img src="../pic/gps167.jpg" alt="Image GPS167" height="300" width="280" align="top" border="0"></a><br> 100102714Sphk </p> 10190731Sjhay <p>This mode expects either the University of Erlangen time string format or the Meinberg standard time string format at 19200/8N1.</p> 10290731Sjhay <p>The University of Erlangen format is preferred. Newer Meinberg GPS receivers can be configured to transmit that format; for older devices, a special firmware version may be available.</p> 10390731Sjhay <p>In this mode some additional GPS receiver status information is also read. However, this requires a point-to-point connection. <a href="#mode18">Mode 18</a> should be used if the device is accessed by a multidrop connection.</p> 10490731Sjhay <p><b>Note:</b> mode 7 must not be used with Meinberg PCI cards; use <a href="#mode2">mode 2</a> instead.<br> 10590731Sjhay <br></p> 10690731Sjhay 10790731Sjhay <li><b><tt>server 127.127.8.0-3 mode 8</tt></b> 10890731Sjhay <p><b><tt><a href="http://www.igel.de">IGEL</a> <a href="http://www.igel.de/eigelmn.html">clock</a></tt></b><br> 10990731Sjhay <a href="http://www.igel.de/eigelmn.html"><img src="../pic/igclock.gif" alt="Image IGEL clock" height="174" width="200" border="0"></a><br> 11090731Sjhay <br></p> 11190731Sjhay 11290731Sjhay <li><b><tt>server 127.127.8.0-3 mode 9</tt></b> 11390731Sjhay <p><b><tt><a href="http://www.trimble.com">Trimble</a> <a href="http://www.trimble.com/cgi/omprod.cgi/pd_om011.html">SVeeSix GPS receiver</a> TAIP protocol (GPS / <<1μs)</tt></b><br> 11490731Sjhay <br></p> 115102893Sphk 116102893Sphk <li><b><tt>server 127.127.8.0-3 mode 10</tt></b> 117102734Sphk <p><b><tt><a href="http://www.trimble.com">Trimble</a> <a href="http://www.trimble.com/cgi/omprod.cgi/pd_om011.html">SVeeSix GPS receiver</a> TSIP protocol (GPS / <<1μs) (no kernel support yet)</tt></b><br> 118102734Sphk <a href="http://www.trimble.com/cgi/omprod.cgi/pd_om011.html"><img src="../pic/pd_om011.gif" alt="Image SVeeSix-CM3" height="100" width="420" align="top" border="0"></a><br> 119102734Sphk <a href="http://www.trimble.com/cgi/omprod.cgi/pd_om006.html"><img src="../pic/pd_om006.gif" alt="Image Lassen-SK8" height="100" width="420" border="0"></a><br> 120102734Sphk <br></p> 121102734Sphk 122102734Sphk <li><b><tt>server 127.127.8.0-3 mode 11</tt></b> 123102734Sphk <p><b><tt>Radiocode Clocks Ltd RCC 8000 Intelligent Off-Air Master Clock support </tt></b><br> 124102734Sphk <br></p> 125102734Sphk 126102734Sphk <li><b><tt>server 127.127.8.0-3 mode 12</tt></b> 127102734Sphk <p><b><tt><a href="http://www.hopf-time.com">HOPF</a> <a href="http://www.hopf-time.com/kart6021.html">Funkuhr 6021</a></tt></b><br> 128102734Sphk <a href="http://www.hopf-time.com/engl/kart6021.html"><img src="../pic/fg6021.gif" alt="Image DCF77 Interface Board" height="207" width="238" align="top" border="0"></a><br> 129102734Sphk <br></p> 130102734Sphk 131102734Sphk <li><b><tt>server 127.127.8.0-3 mode 13</tt></b> 132102734Sphk <p><b><tt>Diem's Computime Radio Clock</tt></b><br> 133102714Sphk <br></p> 134102714Sphk 13590731Sjhay <li><b><tt>server 127.127.8.0-3 mode 14</tt></b> 13690731Sjhay <p><b><tt>RAWDCF receiver (DTR=high/RTS=low)</tt></b><br> 13790731Sjhay <br></p> 13890731Sjhay 13990731Sjhay <li><b><tt>server 127.127.8.0-3 mode 15</tt></b> 14090731Sjhay <p><b><tt>WHARTON 400A Series Clocks with a 404.2 Serial Interface</tt></b><br> 14190731Sjhay <br></p> 14290731Sjhay 14390731Sjhay <li><b><tt>server 127.127.8.0-3 mode 16</tt></b> 14490731Sjhay <p><b><tt>RAWDCF receiver (DTR=low/RTS=high) </tt></b><br> 145102714Sphk <br></p> 14690731Sjhay 14790731Sjhay <li><b><tt>server 127.127.8.0-3 mode 17</tt></b> 14890731Sjhay <p><b><tt>VARITEXT Receiver (MSF) </tt></b><br> 14990731Sjhay <br></p> 15090731Sjhay 15190731Sjhay <li><a name="mode18"></a><b><tt>server 127.127.8.0-3 mode 18</tt></b> 15290731Sjhay <p><b><tt><a href="http://www.meinberg.de">Meinberg </a><a href="http://www.meinberg.de/english/products/timesource.htm#gps---freq_sync">GPS16x/GPS17x receivers</a> (GPS / <<1μs)</tt></b><br> 15390731Sjhay </p> 15490731Sjhay <p>This mode works without additional data communication (version, GPS status etc.) and thus should be used with multidrop, heterogeneous multiclient operation.</p> 15590731Sjhay <p><b>Note:</b> mode 18 must not be used with Meinberg PCI cards, use mode 2 instead.<br> 15690731Sjhay <br></p> 15790731Sjhay <li><b><tt>server 127.127.8.0-3 mode 19</tt></b> 15890731Sjhay <p><b><tt>Gude Analog- und Digitalsystem GmbH 'Expert mouseCLOCK USB v2.0'</tt></b><br> 15990731Sjhay <br></p> 16090731Sjhay 16190731Sjhay </ul> 162102929Sphk <p>Actual data formats and setup requirements of the various clocks can be found in <a href="../parsedata.html">NTP PARSE clock data formats</a>.</p> 16390731Sjhay <h4>Operation</h4> 164102929Sphk <p>The reference clock support software 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> 165102929Sphk <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 synchronization, unless a disruption in time code transmission is detected (possible power loss). The trust period is dependent on the receiver oscillator and thus is a function of clock type.</p> 166102931Sphk <p>Raw DCF77 pulses can be fed via a level converter to the RXD pin of an RS-232 serial port (pin 3 of a 25-pin connector or pin 2 of a 9-pin connector). The telegrams are decoded and used for synchronization. DCF77 AM receivers can be bought for as little as $25. The accuracy is dependent on the receiver and is somewhere between 2ms (expensive) and 10ms (cheap). Synchronization ceases when reception of the DCF77 signal deteriorates, since 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. During transmitter shutdowns you are out of luck unless you have other NTP servers with alternate time sources available.</p> 167102929Sphk <p>In addition to the PPS loopfilter control, a true PPS hardware signal can be utilized via the PPSAPI interface. PPS pulses are usually fed via a level converter to the DCD pin of an RS-232 serial port (pin 8 of a 25-pin connector or pin 1 of a 9-pin connector). To select PPS support, the mode parameter is the mode value as above plus 128. If 128 is not added to the mode value, PPS will be detected to be available but will not be used. 168102929Sphk </p> 169102929Sphk <h4>Hardware PPS support<br> 170102929Sphk </h4> 171102929Sphk <p>For PPS to be used, add 128 to the mode parameter.</p> 172102895Sphk <p>If the PPS signal is fed in from a device different from the device providing the serial communication (/dev/refclock-{0..3}), this device is configured as /dev/refclockpps-{0..3}. This allows the PPS information to be fed in e.g. via the parallel port (if supported by the underlying operation system) and the date/time telegrams to be handled via the serial port.</p> 173102929Sphk <h4>Monitor Data</h4> 17490731Sjhay <p>Clock state statistics are written hourly to the syslog service. Online information can be found by examining the clock variables via the <code>ntpq cv</code> command.<br> 17590731Sjhay Some devices have quite extensive additional information (GPS16x/GPS17x, Trimble). The driver reads out much of the internal GPS data 17690731Sjhay and makes it accessible via clock variables. To find out about additional variable names, query for the clock_var_list variable on 17790731Sjhay a specific clock association as shown below. 17890731Sjhay </p> 179102734Sphk <p>First let <code>ntpq</code> display the table of associations:</p> 18090731Sjhay <pre> 18190731Sjhay ntpq> as 182102734Sphk ind assID status conf reach auth condition last_event cnt 18390731Sjhay =========================================================== 18490731Sjhay 1 19556 9154 yes yes none falsetick reachable 5 18590731Sjhay 2 19557 9435 yes yes none candidat clock expt 3 18690731Sjhay 3 19558 9714 yes yes none pps.peer reachable 1 18790731Sjhay </pre> 18890731Sjhay <p>Then switch to raw output. This may be required because of display limitations in ntpq/ntpd - so large lists need to be retrieved in several queries.</p> 18990731Sjhay <pre> 19090731Sjhay ntpq> raw 19190731Sjhay Output set to raw 19290731Sjhay </pre> 19390731Sjhay <p>Use the cv command to read the list of clock variables of a selected association:</p> 194102734Sphk <pre> 19590731Sjhay ntpq> cv 19557 clock_var_list 19690731Sjhay </pre> 19790731Sjhay <p>The long output of the command above looks similar to:</p> 19890731Sjhay <pre> 19990731Sjhay assID=19557 status=0x0000, 200102734Sphk clock_var_list="type,timecode,poll,noreply,badformat,baddata,fudgetime1, 201102734Sphk fudgetime2,stratum,refid,flags,device,clock_var_list,refclock_time,refclock_status, 202102734Sphk refclock_format,refclock_states,refclock_id,refclock_iomode,refclock_driver_version, 203102734Sphk meinberg_gps_status,gps_utc_correction,gps_message,meinberg_antenna_status,gps_tot_51, 204102734Sphk gps_tot_63,gps_t0a,gps_cfg[1],gps_health[1],gps_cfg[2],gps_health[2],gps_cfg[3], 20590731Sjhay gps_health[3],gps_cfg[4],gps_health[4],gps_cfg[5]" 20690731Sjhay </pre> 20790731Sjhay <p>Then use the cv command again to list selected clock variables. The following command must be entered as a single line:</p> 208102734Sphk <pre> 20990731Sjhay ntpq> cv 19557 refclock_status,refclock_format,refclock_states,refclock_id, 21090731Sjhay refclock_iomode,refclock_driver_version,meinberg_gps_status,gps_utc_correction, 21190731Sjhay gps_message,meinberg_antenna_status,gps_tot_51,gps_tot_63,gps_t0a,gps_cfg[1], 21290731Sjhay gps_health[1],gps_cfg[2],gps_health[2],gps_cfg[3],gps_health[3],gps_cfg[4], 21390731Sjhay gps_health[4],gps_cfg[5] 21490731Sjhay </pre> 21590731Sjhay <p>The output of the command above is wrapped around depending on the screen width and looks similar to:</p> 21690731Sjhay <pre> 21790731Sjhay status=0x0003, 21890731Sjhay refclock_status="UTC DISPLAY; TIME CODE; PPS; POSITION; (LEAP INDICATION; 21990731Sjhay PPS SIGNAL; POSITION)", 22090731Sjhay refclock_format="Meinberg GPS Extended", 22190731Sjhay refclock_states="*NOMINAL: 21:21:36 (99.99%); FAULT: 00:00:03 (0.00%); 22290731Sjhay running time: 21:21:39", 22390731Sjhay refclock_id="GPS", refclock_iomode="normal", 22490731Sjhay refclock_driver_version="refclock_parse.c,v 4.77 2006/08/05 07:44:49 22590731Sjhay kardel RELEASE_20060805_A", 22690731Sjhay meinberg_gps_status="[0x0000] <OK>", 22790731Sjhay gps_utc_correction="current correction 14 sec, last correction 22890731Sjhay on c7619a00.00000000 Sun, Jan 1 2006 0:00:00.000", 22990731Sjhay gps_message="/PFU3SOP-4WG14EPU0V1KA", 23090731Sjhay meinberg_antenna_status="RECONNECTED on 2006-07-18 08:13:20.0000000 (+0000) 23190731Sjhay UTC CORR, LOCAL TIME, reconnect clockoffset +0.0000000 s, 23290731Sjhay disconnect time 0000-00-00 00:00:00.0000000 (+0000) ", 23390731Sjhay gps_tot_51="week 1400 + 3 days + 42300.0000000 sec", 23490731Sjhay gps_tot_63="week 1400 + 3 days + 42294.0000000 sec", 23590731Sjhay gps_t0a="week 1400 + 5 days + 71808.0000000 sec", 236102734Sphk gps_cfg[1]="[0x9] BLOCK II", gps_health[1]="[0x0] OK;SIGNAL OK", 23790731Sjhay gps_cfg[2]="[0x0] BLOCK I", gps_health[2]="[0x3f] PARITY;MULTIPLE ERRS", 23890731Sjhay gps_cfg[3]="[0x9] BLOCK II", gps_health[3]="[0x0] OK;SIGNAL OK", 23990731Sjhay gps_cfg[4]="[0x9] BLOCK II", gps_health[6]="[0x0] OK;SIGNAL OK", 24090731Sjhay gps_cfg[5]="[0x9] BLOCK II" 24190731Sjhay </pre> 24290731Sjhay <h4>Fudge Factors</h4> 24390731Sjhay <dl> 24490731Sjhay <dt><tt>time1 <i>time</i></tt> 24590925Snyan <dd>Specifies the time offset calibration factor, in seconds and fraction. The default value depends on the clock type. 24690925Snyan <dt><tt>time2 <i>time</i></tt> 24790731Sjhay <dd> 24890925Snyan If flag1 is 0, time2 specifies the offset of the PPS signal from the actual time (PPS fine tuning). 24990731Sjhay <dd> 25090731Sjhay If flag1 is 1, time2 specifies the number of seconds a receiver with a premium local oscillator can be trusted after losing synchronisation. 25190731Sjhay <dt><tt>stratum <i>stratum</i></tt> 25290731Sjhay <dd>The stratum for this reference clock. 25390731Sjhay <dt><tt>refid <i>refid</i></tt> 25490731Sjhay <dd>The refid for this reference clock. 25590731Sjhay </dl> 25690731Sjhay <dl> 25790731Sjhay <dt><tt>flag1 { 0 | 1 }</tt> 25890731Sjhay <dd>If 0, the fudge factor <tt>time2</tt> refers to the PPS offset. 25990731Sjhay <dd>If 1, <tt>time2</tt> refers to the TRUST TIME. 26090731Sjhay <dt><tt>flag2 { 0 | 1 }</tt> 26190731Sjhay <dd>If <tt>flag2</tt> is 1, sample PPS on CLEAR instead of on ASSERT. 26290731Sjhay <dt><tt>flag3 { 0 | 1 }</tt> 26390731Sjhay <dd>If <tt>flag3</tt> is 1, link kernel PPS tracking to this refclock instance. 26490925Snyan <dt><tt>flag4 { 0 | 1 }</tt> 26590925Snyan <dd>Delete next leap second instead of adding it. (You'll need to wait a bit for that to happen 8-) 26690925Snyan </dl> 26790925Snyan <span style="font-weight: bold;">Note about auxiliary Sun STREAMS modules (SunOS and Solaris):</span><br> 26890925Snyan <dl> 26990925Snyan <dt>The timecode of these receivers can be 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 - 2.8. It can be linked directly into the kernel or loaded via the loadable driver mechanism.) This STREAMS module can be adapted to convert different time code formats. Nowadays the PPSAPI mechanism is usually used. 27090925Snyan </dl> 27190925Snyan <h4>Making your own PARSE clocks</h4> 27290731Sjhay <p>The parse clock mechanism deviates from the way other NTP reference clocks work. For a short description of how to build parse reference clocks, see <a href="../parsenew.html">making PARSE clocks</a>.</p> 27390925Snyan <p>Additional Information</p> 27490731Sjhay <p><a href="../refclock.html">Reference Clock Drivers</a></p> 27590731Sjhay <hr> 27690731Sjhay <script type="text/javascript" language="javascript" src="scripts/footer.txt"></script> 27790731Sjhay </body> 27890731Sjhay 27990731Sjhay</html> 28090731Sjhay
