mirror of
https://git.FreeBSD.org/src.git
synced 2024-12-18 10:35:55 +00:00
179 lines
5.3 KiB
HTML
179 lines
5.3 KiB
HTML
<HTML>
|
|
<HEAD>
|
|
<META NAME="GENERATOR" CONTENT="Adobe PageMill 3.0 per Windows">
|
|
<META HTTP-EQUIV="Content-Type" CONTENT="text/html; charset=iso-8859-1">
|
|
<TITLE>PTB Modem Time Service </TITLE>
|
|
</HEAD>
|
|
<BODY>
|
|
|
|
<H3>PTB Modem Time Service and other European Laboratories Time
|
|
Services</H3>
|
|
|
|
<HR ALIGN=LEFT>
|
|
|
|
<H4>Synopsis</H4>
|
|
|
|
<P>Address: 127.127.23.<I>u</I> <BR>
|
|
Reference ID: <TT>PTB</TT> <BR>
|
|
Driver ID: <TT>ACTS_PTB</TT><BR>
|
|
Serial Port: <TT>/dev/ptb<I>u</I></TT>; 1200 baud, 8-bits, no
|
|
parity <BR>
|
|
Requires: <TT>/usr/include/sys/termios.h</TT> header file with
|
|
modem control</P>
|
|
|
|
<H4>Description</H4>
|
|
|
|
<P>This driver supports the PTB Automated Computer Time Service
|
|
(ACTS) and it is a modified version of the NIST ACTS driver so
|
|
see it for more informations..</P>
|
|
|
|
<P>It periodically dials a prespecified telephone number, receives
|
|
the PTB timecode data and calculates the local clock correction.
|
|
It designed primarily for use when neither a radio clock nor connectivity
|
|
to Internet time servers is available. For the best accuracy,
|
|
the individual telephone line/modem delay needs to be calibrated
|
|
using outside sources.</P>
|
|
|
|
<P>The only change between this driver and the NIST one is the
|
|
data format. Infact PTB data format is the following:</P>
|
|
|
|
<P><FONT SIZE="-1" FACE="Courier New">Data format<BR>
|
|
0000000000111111111122222222223333333333444444444455555555556666666666777777777
|
|
7<BR>
|
|
0123456789012345678901234567890123456789012345678901234567890123456789012345678
|
|
9<BR>
|
|
1995-01-23 20:58:51 MEZ 10402303260219950123195849740+40000500
|
|
*<BR>
|
|
A B C D EF G H IJ K L M N O P Q R S T U V W
|
|
XY Z<CR><LF><BR>
|
|
A year<BR>
|
|
B month<BR>
|
|
C day<BR>
|
|
D hour<BR>
|
|
E : normally<BR>
|
|
A for DST to ST switch first hour<BR>
|
|
B for DST to ST switch second hour if not marked in H<BR>
|
|
F minute<BR>
|
|
G second<BR>
|
|
H timezone<BR>
|
|
I day of week<BR>
|
|
J week of year<BR>
|
|
K day of year<BR>
|
|
L month for next ST/DST changes<BR>
|
|
M day<BR>
|
|
N hour<BR>
|
|
O UTC year<BR>
|
|
P UTC month<BR>
|
|
Q UTC day<BR>
|
|
R UTC hour<BR>
|
|
S UTC minute<BR>
|
|
T modified julian day (MJD)<BR>
|
|
U DUT1<BR>
|
|
V direction and month if leap second<BR>
|
|
W signal delay (assumed/measured)<BR>
|
|
X sequence number for additional text line in Y<BR>
|
|
Y additional text<BR>
|
|
Z on time marker (* - assumed delay / # measured delay)<BR>
|
|
<CR>!<LF> ! is second change !<BR>
|
|
</FONT><BR>
|
|
This format is an ITU-R Recommendation (ITU-R TF583.4) and is now available from the primary
|
|
timing centres of the following countries:
|
|
Austria, Belgium, Germany, Italy, The Netherlands, Poland, Portugal, Romania, Spain, Sweden,
|
|
Switzerland, Turkey, United Kingdom.
|
|
Some examples are:
|
|
</P>
|
|
|
|
<UL>
|
|
<LI>In Germany by Physikalisch-Technische Bundesanstalt (PTB)'s
|
|
timecode service. Phone number: +49 5 31 51 20 38.
|
|
</UL>
|
|
|
|
<BLOCKQUOTE>
|
|
<P>For more detail, see <A HREF="http://www.ptb.de/english/org/4/43/433/disse.htm">http://www.ptb.de/english/org/4/43/433/disse.htm</A></P>
|
|
</BLOCKQUOTE>
|
|
|
|
<UL>
|
|
<LI>In the UK by National Physical Laboratory (NPL)'s TRUETIME
|
|
service. Phone number: 0891 516 333
|
|
</UL>
|
|
|
|
<BLOCKQUOTE>
|
|
<P>For more detail, see <A HREF="http://www.npl.co.uk/npl/ctm/truetime.html">http://www.npl.co.uk/npl/ctm/truetime.html</A></P>
|
|
</BLOCKQUOTE>
|
|
|
|
<UL>
|
|
<LI>In Italy by Istituto Elettrotecnico Nazionale "Galileo
|
|
Ferrais" (IEN)'s CTD service. Phone number: 166 11 46
|
|
15
|
|
</UL>
|
|
|
|
<BLOCKQUOTE>
|
|
<P>For more detail, see <A HREF="http://www.ien.it/tf/time/Pagina42.html">http://www.ien.it/tf/time/Pagina42.html</A></P>
|
|
</BLOCKQUOTE>
|
|
|
|
<UL>
|
|
<LI>In Switzerland by Swiss Federal Office of Metrology 's timecode
|
|
service. Phone number: 031 323 32 25
|
|
</UL>
|
|
|
|
<BLOCKQUOTE>
|
|
<P>For more detail, see <A HREF="http://www.ofmet.admin.ch/de/labors/4/Zeitvert.html%20">http://www.ofmet.admin.ch/de/labors/4/Zeitvert.html
|
|
</A></P>
|
|
</BLOCKQUOTE>
|
|
|
|
<UL>
|
|
<LI>In Sweden by SP Swedish National Testing and Research Institute
|
|
's timecode service. Phone number: +46 33 415783
|
|
</UL>
|
|
|
|
<BLOCKQUOTE>
|
|
<P>For more detail, see <A HREF="http://www.sp.se/pne/ElectricalMetrology/ElMeteng/frameset.htm">http://www.sp.se/pne/ElectricalMetrology/ElMeteng/frameset.htm</A><BR>
|
|
<BR>
|
|
</P>
|
|
</BLOCKQUOTE>
|
|
|
|
<H4>Fudge Factors</H4>
|
|
|
|
<DL>
|
|
<DT><TT>time1 <I>time</I></TT>
|
|
<DD>Specifies the time offset calibration factor, in seconds
|
|
and fraction, with default 0.0.
|
|
<DT><TT>time2 <I>time</I></TT>
|
|
<DD>Not used by this driver.
|
|
<DT><TT>stratum <I>number</I></TT>
|
|
<DD>Specifies the driver stratum, in decimal from 0 to 15, with
|
|
default 0.
|
|
<DT><TT>refid <I>string</I></TT>
|
|
<DD>Specifies the driver reference identifier, an ASCII string
|
|
from one to four characters, with default PTB.
|
|
<DT><TT>flag1 0 | 1</TT>
|
|
<DD>Not used by this driver.
|
|
<DT><TT>flag2 0 | 1</TT>
|
|
<DD>Not used by this driver.
|
|
<DT><TT>flag3 0 | 1</TT>
|
|
<DD>Not used by this driver.
|
|
<DT><TT>flag4 0 | 1</TT>
|
|
<DD>Not used by this driver.
|
|
</DL>
|
|
|
|
<P>Additional Information</P>
|
|
|
|
<P>A keyword in the ntp.conf file permits a direct connection
|
|
to a serial port of source of time like IEN CTD signal. It is
|
|
sufficient to use the string DIRECT in place of the phone number.</P>
|
|
|
|
<P>Example:</P>
|
|
|
|
<P><FONT FACE="Courier New">server 127.127.23.1</FONT></P>
|
|
|
|
<P><FONT FACE="Courier New">phone DIRECT</FONT></P>
|
|
|
|
<P><A HREF="refclock.htm">Reference Clock Drivers</A> <HR ALIGN=LEFT></P>
|
|
|
|
<ADDRESS>by Marco Mascarello (masca@tf.ien.it) for David L. Mills
|
|
(mills@udel.edu)</ADDRESS>
|
|
|
|
</BODY>
|
|
</HTML>
|
|
|