1ea906c41SOllivier Robert<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"> 2ea906c41SOllivier Robert 3ea906c41SOllivier Robert<html> 4ea906c41SOllivier Robert 5ea906c41SOllivier Robert <head> 6ea906c41SOllivier Robert <meta http-equiv="Content-Type" content="text/html;charset=iso-8859-1"> 7ea906c41SOllivier Robert <meta name="GENERATOR" content="Mozilla/4.06 [en] (X11; I; FreeBSD 3.0-CURRENT i386) [Netscape]"> 8ea906c41SOllivier Robert <title>Rockwell Jupiter GPS Receiver</title> 9ea906c41SOllivier Robert <link href="../scripts/style.css" type="text/css" rel="stylesheet"> 10ea906c41SOllivier Robert </head> 11ea906c41SOllivier Robert 12ea906c41SOllivier Robert <body> 13ea906c41SOllivier Robert <h3>Rockwell Jupiter GPS receiver</h3> 14*2b15cb3dSCy Schubert<p>Last update: 15*2b15cb3dSCy Schubert <!-- #BeginDate format:En2m -->21-Oct-2010 23:44<!-- #EndDate --> 16*2b15cb3dSCy Schubert UTC</p> 17ea906c41SOllivier Robert <hr> 18ea906c41SOllivier Robert <h4>Synopsis</h4> 19ea906c41SOllivier Robert <p>Address: 127.127.31.<i>u</i><br> 20ea906c41SOllivier Robert Reference ID: <tt>GPS</tt><br> 21ea906c41SOllivier Robert Driver ID: JUPITER<br> 22ea906c41SOllivier Robert Serial Port: <tt>/dev/gps</tt><i>u</i>; 9600 baud, 8-bits, no parity.</p> 23ea906c41SOllivier Robert <h4>Description</h4> 24ea906c41SOllivier Robert <p>This driver supports at least some models of the <a href="http://www.navman.com/oem/products/receivers/jupiter/">Rockwell Jupiter <tt>GPS</tt> receivers</a> (Jupiter 11, Jupiter-T), they must at least support the <i>Zodiac Binary Protocol</i>.</p> 25ea906c41SOllivier Robert <p>The driver requires a standard <tt>PPS</tt> interface for the pulse-per-second output from the receiver. The serial data stream alone does not provide precision time stamps, whereas the PPS output is precise down to 40 ns (1 sigma) for the Jupiter 11 and 25 ns (1 sigma) for Jupiter-T according to the documentation. If you do not have the PPS signal available, then you should probably not be using the Jupiter receiver as a time source. This driver requires a <tt>PPS</tt> signal and the time output from Jupiter receivers is not predictable in <tt>NMEA</tt> mode; the reported time can take one second steps.</p> 26ea906c41SOllivier Robert <h4>Monitor Data</h4> 27ea906c41SOllivier Robert <p>The driver always puts a lot of useful information on the clockstats file, and when run with debugging can be quite chatty on stdout. When first starting to use the driver you should definitely review the information written to the clockstats file to verify that the driver is running correctly.</p> 28ea906c41SOllivier Robert <h4>Fudge Factors</h4> 29ea906c41SOllivier Robert <dl> 30ea906c41SOllivier Robert <dt><tt>time1 <i>time</i></tt> 31ea906c41SOllivier Robert <dd>Specifies the time offset calibration factor, in seconds and fraction, with default 0.0. 32ea906c41SOllivier Robert <dt><tt>time2 <i>time</i></tt> 33ea906c41SOllivier Robert <dd>Not used by this driver. Should be left at zero. 34ea906c41SOllivier Robert <dt><tt>stratum <i>number</i></tt> 35ea906c41SOllivier Robert <dd>Specifies the driver stratum, in decimal from 0 to 15, with default 0. 36ea906c41SOllivier Robert <dt><tt>refid <i>string</i></tt> 37ea906c41SOllivier Robert <dd>Specifies the driver reference identifier, an <tt>ASCII</tt> string from one to four characters, with default <tt>GPS</tt>. 38ea906c41SOllivier Robert <dt><tt>flag1 0 | 1</tt> 39ea906c41SOllivier Robert <dd>Not used by this driver. 40ea906c41SOllivier Robert <dt><tt>flag2 0 | 1</tt> 41ea906c41SOllivier Robert <dd>Specifies the mobility of the <tt>GPS</tt> receiver: 0 for walking (default), 1 for driving. 42ea906c41SOllivier Robert <dt><tt>flag3 0 | 1</tt> 43ea906c41SOllivier Robert <dd>Specifies the <tt>PPS</tt> signal on-time edge: 0 for assert (default), 1 for clear. 44ea906c41SOllivier Robert <dt><tt>flag4 0 | 1</tt> 45ea906c41SOllivier Robert <dd>Not used by this driver. 46ea906c41SOllivier Robert </dl> 47ea906c41SOllivier Robert <h4>Additional Information</h4> 48ea906c41SOllivier Robert <p>The driver was resurrected from a sorry state using the Windows NT port and a Jupiter 11, and has since seen little testing on other platforms. On Windows there exist a barrier though, as there is no publicly available <tt>PPSAPI</tt> implementation, at least not to my knowledge. However, there has been one success report using Linux 2.4.20 and PPSkit 2.1.1.</p> 49ea906c41SOllivier Robert <p>The Jupiter receivers seem to have quite a few names. They are referred to at least as Rockwell receivers, Navman receivers, Zodiac receivers, Conexant receivers and SiRF Technology receivers. Rockwell seems to be the original and most commonly used name and Navman seems to be the current supplier.</p> 50ea906c41SOllivier Robert <p><b>Configuration</b></p> 51ea906c41SOllivier Robert <p>The edge of the <tt>PPS</tt> signal that is `on-time' can be set with <tt>flag2</tt>. There is currently no way to cause the <tt>PPS</tt> signal to control the kernel <tt>PLL</tt>.</p> 52ea906c41SOllivier Robert <p><b>Performance</b></p> 53ea906c41SOllivier Robert <p>The performance is largely unexplored. I have achieved submillisecond stability using a Jupiter 11, but the poor result is more than likely due to the proprietary <tt>PPSAPI</tt> implementation or Windows itself.</p> 54ea906c41SOllivier Robert <p>This driver does not handle leap seconds.</p> 55ea906c41SOllivier Robert <hr> 56ea906c41SOllivier Robert <script type="text/javascript" language="javascript" src="../scripts/footer.txt"></script> 57ea906c41SOllivier Robert </body> 58ea906c41SOllivier Robert 59ea906c41SOllivier Robert</html> 60ea906c41SOllivier Robert 61ea906c41SOllivier Robert= 62