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7 Installation
7.6 Powering Up the System
If both the antenna and the power supply have been connected the system is ready to operate. About 10 seconds
to 3 minutes after power-up the receiver has warmed up and operates with the required accuracy. If the receiver
nds valid almanac and ephemeris data in its battery buered memory and the receivers position has not changed
signicantly since its last operation the receiver can nd out which satellites are in view now. Only a single satellite
needs to be received to synchronize and generate output pulses, so synchronization can be achieved maximally
one to 10 minutes after power-up. After 20 minutes of operation the OCXO is full adjusted and the generated
frequencies are within the spezied tolerances.
If the receiver position has changed by some hundred kilometers since last operation, the satellites real ele-
vation and doppler might not match those values expected by the receiver thus forcing the receiver to start
scanning for satellites. This mode is called Warm Boot because the receiver can obtain ID numbers of existing
satellites from the valid almanac. When the receiver has found four satellites in view it can update its new position
and switch to Normal Operation. If the almanac has been lost because the battery had been disconnected the
receiver has to scan for a satellite and read in the current almanacs. This mode is called Cold Boot. It takes
12 minutes until the new almanac is complete and the system switches to Warm Boot mode scanning for other
satellites.
In the default mode of operation, neither pulse and synthesizer outputs nor the serial ports will be enabled
after power-up until synchronization has been achieved. However, it is possible to congure some or all of those
outputs to be enabled immediately after power-up. If the system starts up in a new environment (e. g. receiver
position has changed or new power supply) it can take some minutes until the OCXOs output frequency has
been adjusted. Up to that time accuracy of frequency drops to 10
-8
reducing the accuracy of pulses to +-3
µ
s.
7.7 Change the Fuse
Ÿ
Keep a spare fuse ready for replacement. Make sure rated current and characteristics are
correct. ATTENTION : The fuse must be suited for breaking DC current.
Ÿ
Disconnect all signal lines, such as error relais, serial cables and GPS antenna.
Ÿ
Disconnect the device from mains ! Switch off the device at first, afterwards release the
screws of the 5pole mains connector and remove it from the device
Ÿ
Replace the fuse.
Ÿ
Connect all cables and signal lines in reverse order and switch on the device after
checking there is no potential danger caused by the installation.
Type
Size
T 0.63A / 250V acc. to IEC 60127
with extinguishing agent
5 x 20mm
Fuse
SB (SlowBlow)
20
Date: 27th January 2016
GPS164
Содержание GPS164-LQ/PPFO-3/REL-1/DAHS
Страница 1: ...MANUAL GPS164 PPFO 3 REL 1 DAHS 27th January 2016 Meinberg Radio Clocks GmbH Co KG ...
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Страница 6: ...Page 2 1 General Details 2 Date 27th January 2016 GPS164 ...
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Страница 17: ...6 4 Time code outputs Page 13 6 4 5 AFNOR Standard Format GPS164 Date 27th January 2016 13 ...