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5 <TITLE>PTB Modem Time Service </TITLE>
9 <H3>PTB Modem Time Service and other European Laboratories Time
16 <P>Address: 127.127.23.<I>u</I> <BR>
17 Reference ID: <TT>PTB</TT> <BR>
18 Driver ID: <TT>ACTS_PTB</TT><BR>
19 Serial Port: <TT>/dev/ptb<I>u</I></TT>; 1200 baud, 8-bits, no
21 Requires: <TT>/usr/include/sys/termios.h</TT> header file with
26 <P>This driver supports the PTB Automated Computer Time Service
27 (ACTS) and it is a modified version of the NIST ACTS driver so
28 see it for more informations..</P>
30 <P>It periodically dials a prespecified telephone number, receives
31 the PTB timecode data and calculates the local clock correction.
32 It designed primarily for use when neither a radio clock nor connectivity
33 to Internet time servers is available. For the best accuracy,
34 the individual telephone line/modem delay needs to be calibrated
35 using outside sources.</P>
37 <P>The only change between this driver and the NIST one is the
38 data format. Infact PTB data format is the following:</P>
40 <P><FONT SIZE="-1" FACE="Courier New">Data format<BR>
41 0000000000111111111122222222223333333333444444444455555555556666666666777777777
43 0123456789012345678901234567890123456789012345678901234567890123456789012345678
45 1995-01-23 20:58:51 MEZ 10402303260219950123195849740+40000500
47 A B C D EF G H IJ K L M N O P Q R S T U V W
48 XY Z<CR><LF><BR>
54 A for DST to ST switch first hour<BR>
55 B for DST to ST switch second hour if not marked in H<BR>
62 L month for next ST/DST changes<BR>
70 T modified julian day (MJD)<BR>
72 V direction and month if leap second<BR>
73 W signal delay (assumed/measured)<BR>
74 X sequence number for additional text line in Y<BR>
76 Z on time marker (* - assumed delay / # measured delay)<BR>
77 <CR>!<LF> ! is second change !<BR>
79 This format is an ITU-R Recommendation (ITU-R TF583.4) and is now available from the primary
80 timing centres of the following countries:
81 Austria, Belgium, Germany, Italy, The Netherlands, Poland, Portugal, Romania, Spain, Sweden,
82 Switzerland, Turkey, United Kingdom.
87 <LI>In Germany by Physikalisch-Technische Bundesanstalt (PTB)'s
88 timecode service. Phone number: +49 5 31 51 20 38.
92 <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>
96 <LI>In the UK by National Physical Laboratory (NPL)'s TRUETIME
97 service. Phone number: 0891 516 333
101 <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>
105 <LI>In Italy by Istituto Elettrotecnico Nazionale "Galileo
106 Ferrais" (IEN)'s CTD service. Phone number: 166 11 46
111 <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>
115 <LI>In Switzerland by Swiss Federal Office of Metrology 's timecode
116 service. Phone number: 031 323 32 25
120 <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
125 <LI>In Sweden by SP Swedish National Testing and Research Institute
126 's timecode service. Phone number: +46 33 415783
130 <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>
135 <H4>Fudge Factors</H4>
138 <DT><TT>time1 <I>time</I></TT>
139 <DD>Specifies the time offset calibration factor, in seconds
140 and fraction, with default 0.0.
141 <DT><TT>time2 <I>time</I></TT>
142 <DD>Not used by this driver.
143 <DT><TT>stratum <I>number</I></TT>
144 <DD>Specifies the driver stratum, in decimal from 0 to 15, with
146 <DT><TT>refid <I>string</I></TT>
147 <DD>Specifies the driver reference identifier, an ASCII string
148 from one to four characters, with default PTB.
149 <DT><TT>flag1 0 | 1</TT>
150 <DD>Not used by this driver.
151 <DT><TT>flag2 0 | 1</TT>
152 <DD>Not used by this driver.
153 <DT><TT>flag3 0 | 1</TT>
154 <DD>Not used by this driver.
155 <DT><TT>flag4 0 | 1</TT>
156 <DD>Not used by this driver.
159 <P>Additional Information</P>
161 <P>A keyword in the ntp.conf file permits a direct connection
162 to a serial port of source of time like IEN CTD signal. It is
163 sufficient to use the string DIRECT in place of the phone number.</P>
167 <P><FONT FACE="Courier New">server 127.127.23.1</FONT></P>
169 <P><FONT FACE="Courier New">phone DIRECT</FONT></P>
171 <P><A HREF="refclock.htm">Reference Clock Drivers</A> <HR ALIGN=LEFT></P>
173 <ADDRESS>by Marco Mascarello (masca@tf.ien.it) for David L. Mills
174 (mills@udel.edu)</ADDRESS>