Powering up NTS time server If both the antenna GPS and/or, DCF77, and the power 100-250VAC supply have been connected the system is ready to operate. You can turn on a power switch located on the back panel of NTS-x000. Typically, time duration of NTS-x000 power-up is enough for the antenna (GPS) box receiver to start to operate with the required accuracy. If the GPS receiver finds valid almanac and ephemeris data in its battery burred memory (and the receiver position has not changed significantly since its last operation) the receiver can find out which satellites are in its view at that now. Four satellites needs to be found to synchronize and generate output pulses. If the receiver position has changed by some kilometers since the last operation, the satellites real elevation and Doppler might not match the values expected by the receiver thus forcing the receiver to start scanning for satellites. When the receiver has found four satellites in its view it can update its new position and switch to Normal Operation. If the almanac has been lost because the battery had been disconnection the receiver has to scan for a satellite and read in the current almanacs. When antenna has clear view of the sky it takes up to 30 minutes until the new almanac is completed and the system starts to operate. For this time NTS-x000 will operate from it's internal quartz time clocks. After starting up the system the network function is initiated and the program for communication between GPS and NTP becomes active. The following screen appear on LCD display while starting:
17-09-2010 Err sync 18:02:21 sat A= 5/12
From the left side there are: date and time, error status, UTC time, number of satellites reached per total amount of visible satellites. It is possible to setup much shorter startup time of
NTP (about 1 minute) by selecting a special “Fast”
option in “Misc” menu of SETUP. This can be helpful for
environments with a high risk of unexpected power down.
Using this option results in less accurate (approx 1s
error of time information provided by NTP service
during first 3-4 minutes of operation).
17-09-2010 OK 18:02:21 sat A= 5/12
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