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diff --git a/contrib/ntp/html/driver26.htm b/contrib/ntp/html/driver26.htm new file mode 100644 index 0000000..eabbc96 --- /dev/null +++ b/contrib/ntp/html/driver26.htm @@ -0,0 +1,109 @@ +<HTML> +<HEAD> + <META HTTP-EQUIV="Content-Type" CONTENT="text/html; charset=iso-8859-1"> + <META NAME="GENERATOR" CONTENT="Mozilla/4.01 [en] (Win95; I) [Netscape]"> + <TITLE>Hewlett Packard 58503A GPS Receiver +</TITLE> +</HEAD> +<BODY> + +<H3> +Hewlett Packard 58503A GPS Receiver</H3> + +<HR> +<H4> +Synopsis</H4> +Address: 127.127.26.<I>u</I> +<BR>Reference ID: <TT>GPS</TT> +<BR>Driver ID: <TT>GPS_HP</TT> +<BR>Serial Port: <TT>/dev/hpgps<I>u</I></TT>; 9600 baud, 8-bits, no parity +<H4> +Description</H4> +This driver supports the HP 58503A Time and Frequency Reference Receiver. +It uses HP SmartClock (TM) to implement an Enhanced GPS receiver. The receiver +accuracy when locked to GPS in normal operation is better than 1 usec. +The accuracy when operating in holdover is typically better than 10 us +per day. It receiver should be operated with factory default settings. +Initial driver operation: expects the receiver to be already locked to +GPS, configured and able to output timecode format 2 messages. + +<P>The driver uses the poll sequence <TT>:PTIME:TCODE?</TT> to get a response +from the receiver. The receiver responds with a timecode string of ASCII +printing characters, followed by a <cr><lf>, followed by a prompt +string issued by the receiver, in the following format: +<PRE>T#yyyymmddhhmmssMFLRVcc<cr><lf></PRE> +The driver processes the response at the <cr> and <lf><cr> and +<lf>, so what the driver sees is the prompt from the previous poll, +followed by this timecode. The prompt from the current poll is (usually) +left unread until the next poll. So (except on the very first poll) the +driver sees this: +<PRE>T#yyyymmddhhmmssMFLRVcc<cr><lf></PRE> +The T is the on-time character, at 980 msec. before the next 1PPS edge. +The # is the timecode format type. We look for format 2. Without any of +the CLK or PPS stuff, then, the receiver buffer timestamp at the <cr>y +is 24 characters later, which is about 25 msec. at 9600 bps, so the first +approximation for fudge time1 is nominally -0.955 seconds. This number +probably needs adjusting for each machine / OS type, so far: -0.955000 +on an HP 9000 Model 712/80 HP-UX 9.05 -0.953175 on an HP 9000 Model 370 +HP-UX 9.10 +<H4> +Fudge Factors</H4> + +<DL> +<DT> +<TT>time1 <I>time</I></TT></DT> + +<DD> +Specifies the time offset calibration factor, in seconds and fraction, +with default 0.0.</DD> + +<DT> +<TT>time2 <I>time</I></TT></DT> + +<DD> +Not used by this driver.</DD> + +<DT> +<TT>stratum <I>number</I></TT></DT> + +<DD> +Specifies the driver stratum, in decimal from 0 to 15, with default 0.</DD> + +<DT> +<TT>refid <I>string</I></TT></DT> + +<DD> +Specifies the driver reference identifier, an ASCII string from one to +four characters, with default <TT>GPS</TT>.</DD> + +<DT> +<TT>flag1 0 | 1</TT></DT> + +<DD> +Not used by this driver.</DD> + +<DT> +<TT>flag2 0 | 1</TT></DT> + +<DD> +Not used by this driver.</DD> + +<DT> +<TT>flag3 0 | 1</TT></DT> + +<DD> +Not used by this driver.</DD> + +<DT> +<TT>flag4 0 | 1</TT></DT> + +<DD> +Not used by this driver.</DD> +</DL> + +<HR> +<ADDRESS> +David L. Mills (mills@udel.edu)</ADDRESS> + +</BODY> +</HTML> |
