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9 Booting the Single Board Computer
The LINUX operating system is loaded from a packed le on the ash disk of the single board computer to a
RAM disk. All les of the ash disk are stored in the RAM disk after booting. Because of that it is guaranteed
that the le system is in a dened condition after restart. This boot process takes approx. two minutes. During
this time the following message appears on the display:
Starting up
please wait...
.....
After starting up the LINUX system the network function is initiated and the program for communication with
the GPS and the NTPD (NTP daemon) is started. After that NTPD starts synchronization with the reference
clocks (usual the hardware clock of the single board computer and the GPS receiver). Until synchronization is
nished the following message is displayed:
NTP: Offs. 1ms Stratum: 1
GPS: NORMAL OPERATION Satellites:9/10
PTP: ok PTP_MASTER GM:00:00:00:00:00:00
Press F1 for help or F2 for setup overview
F1
UTC
Tue, 01.01.2008
12:00:00
F1
UTC Tue, 01.01.2008
12:00:00
For the synchronization of the NTPD with the GPS it is necessary that the GPS receiver is synchronous with the
GPS time. In this case the following message is monitored on the display:
NTP: Offs. 1ms Stratum: 1
GPS: NORMAL OPERATION Satellites:9/10
Press F1 for help or F2 for setup overview
F1
UTC
Tue, 01.01.2008
12:00:00
The second line shows the user that the NTPD is synchronized to the GPS with a certain oset. Because of the
fact that the NTPD controlled internal system time is adjusted by a software PLL (phase locked loop) it takes a
certain time to adjust this oset. The NTPD tries to keep the oset below +-128 ms. If the oset becomes too
large the system time is set with the GPS time. Typically values for the oset are +- 5 ms after the NTPD has
already synchronized and settled.
LANTIME M600 MRS
Date: 31st July 2014
17
Содержание LANTIME M600 MRS
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Страница 62: ...Page 56 12 The WEB Interface 12 4 Configuration Notification 56 Date 31st July 2014 LANTIME M600 MRS ...
Страница 66: ...Page 60 12 The WEB Interface 12 5 Configuration Security 60 Date 31st July 2014 LANTIME M600 MRS ...
Страница 77: ...12 7 Con guration Local Page 71 12 7 Configuration Local LANTIME M600 MRS Date 31st July 2014 71 ...
Страница 84: ...Page 78 12 The WEB Interface 12 8 Configuration Statistics 78 Date 31st July 2014 LANTIME M600 MRS ...
Страница 127: ...15 9 Time Code Page 121 15 9 3 IRIG Standard Format LANTIME M600 MRS Date 31st July 2014 121 ...
Страница 128: ...Page 122 15 Attachment Technical Information 15 9 4 AFNOR Standard Format 122 Date 31st July 2014 LANTIME M600 MRS ...