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Diffstat (limited to 'contrib/ntp/html/driver30.htm')
| -rw-r--r-- | contrib/ntp/html/driver30.htm | 61 |
1 files changed, 36 insertions, 25 deletions
diff --git a/contrib/ntp/html/driver30.htm b/contrib/ntp/html/driver30.htm index fab604b8a318..d2ec9dded64e 100644 --- a/contrib/ntp/html/driver30.htm +++ b/contrib/ntp/html/driver30.htm @@ -17,31 +17,31 @@ Motorola Oncore GPS receiver</H3> <H4> Synopsis</H4> -Address: 127.127.30.0<BR> +Address: 127.127.30.<i>u</i><BR> Reference ID: <TT>GPS</TT><BR> Driver ID: ONCORE<BR> -Serial Port: <TT>/dev/oncore.serial.0</TT>; 9600 baud, 8-bits, +Serial Port: <TT>/dev/oncore.serial.</TT><i>u</i>; 9600 baud, 8-bits, no parity.<BR> -PPS Port: <TT>/dev/oncore.pps.0</TT>; <TT>PPS_CAPTUREASSERT</TT> -required, <TT>PPS_OFFSETASSERT</TT> supported. +PPS Port: <TT>/dev/oncore.pps.</TT><i>u</i>; <TT>PPS_CAPTUREASSERT</TT> +required, <TT>PPS_OFFSETASSERT</TT> supported.<BR> +Configuration File: <TT>/etc/ntp.oncore<TT><i>u</i> or, +<TT>/etc/ntp.oncore.<TT><i>u</i>, or <TT>/etc/ntp.oncore<TT>. <H4> Description</H4> -This driver supports various models of the <A -HREF="http://www.mot.com/AECS/PNSB/products">Motorola Oncore GPS -receivers</A> as long as they support the <I>Motorola Binary -Protocol</I>. - -<P>The three most interesting versions of the Oncore are the "VP", -the "UT+", -and the "Remote" which is a prepackaged "UT+". -The "VP" is no longer available. - -<P>The evaluation kit +This driver supports most models of the +<A HREF="http://www.mot.com/AECS/PNSB/products">Motorola Oncore GPS receivers</A> +(Basic, PVT6, VP, UT, UT+, GT, GT+, SL, M12), +as long as they support the <I>Motorola Binary Protocol</I>. + +<P>The three most interesting versions of the Oncore are the VP, +the UT+, and the "Remote" which is a prepackaged UT+. +The VP is no longer available. +The Motorola evaluation kit can also be recommended, it interfaces to a PC straightaway, using the serial (DCD) or parallel port for PPS input and packs the receiver in a nice and sturdy box. Two less expensive interface kits are available from -<A HREF="http://www.tapr.org">TAPR </A>. +<A HREF="http://www.tapr.org">TAPR</A>. <BR> <CENTER><TABLE NOSAVE > @@ -74,17 +74,27 @@ pulse-per-second output from the receiver. The serial data stream alone does not provide precision time stamps (0-50msec variance, according to the manual), whereas the PPS output is precise down to 50 nsec (1 sigma) for the VP/UT models. +If you do not have the PPS signal available, then you should probably be using +the NMEA driver rather than the Oncore driver. <P>The driver will use the "position hold" mode with user provided coordinates, the receivers built-in site-survey, -or a similar algorithm implemented in this driver. +or a similar algorithm implemented in this driver to determine the antenna position. <H4> Monitor Data</H4> -The driver is quite chatty on stdout if ntpd is run with -debugging. -A manual will be required though. -Additional information is written to the clockstats file, if configured. +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> +In addition, on platforms supporting Shared Memory, all of the messages +received from the Oncore receiver are made available in shared memory for +use by other programs. +See the <A HREF=Oncore-SHMEM.htm> Oncore-SHMEM </A> manual page for +information on how to use this option. +For either debugging or using the SHMEM option, an Oncore Reference Manual +for the specific receiver in use will be required. <H4> Fudge Factors</H4> @@ -141,8 +151,9 @@ Not used by this driver.</DD> Not used by this driver.</DD> </DL> <B>Additional Information</B> -<P>The driver has been tested on FreeBSD, Linux and SunOS. - +<P>The driver was initially developed on FreeBSD, and has since been tested +on Linux, SunOS and Solaris. +<P><B>Configuration</B> <P>There is a driver specific configuration file <TT>/etc/ntp.oncore</TT> that contains information on the startup mode, the location of the GPS receiver, an offset of the PPS signal from zero, and the cable delay. @@ -165,11 +176,11 @@ to UTC(GPS) with better than 50 nsec (1 sigma) accuracy. The limiting factor will be the timebase of the computer and the precision with which you can timestamp the rising flank of the PPS signal. -Using FreeBSD, a FPGA based Timecounter/PPS interface +Using FreeBSD, a FPGA based Timecounter/PPS interface, and an ovenized quartz oscillator, that performance has been reproduced. For more details on this aspect: <A HREF="http://phk.freebsd.dk/rover.html">Sub-Microsecond -timekeeping under FreeBSD</A> +timekeeping under FreeBSD</A>. <HR> <ADDRESS> Poul-Henning Kamp (phk@FreeBSD.org), |