WEMPE 20097, Руководство по эксплуатации

Страница: 32 / 60

WEMPE digital main clock 20097
Operation
32
V3.0 01/2011
1.1.4 Setting of synchronisation rate
The use of GPS receivers without PPS impulse involves a risk in view of the correct
synchronisation of the main clock.
All data frames that correspond to the usual layout are regarded as valid. For GPS receivers
with an up-date rate of more than 1 second, this means for example that the receiver
transmits the same time for up to 5 seconds and then makes a 5-seconds leap forwards.
This results in leaps of the time indicated on the main clock and the secondary clocks and in
some cases even a fast adjustment of the secondary clocks is carried out without interfering
of the user.
In order to eliminate this source of error, modify the synchronisation rate as follows:
1. Remove write protection ( 1.1.1).
2. Press the key
1
several times until
the message on the right appears on
the display:
3. Press the
ENTER
key for confirmation. The cursor starts flashing.
4. Press the key 2 to set whether data is to be synchronised once per second, minute,
hour or day.
NOTICE!
During the period in between two synchronisations, the main clock runs with the
accuracy of the internal oscillator.
5. Press the ENTER key to confirm the modification.
To cancel the modifications, press the
MENUE
key twice.
6. Press the
MENUE
key to return to the date display.
NOTICE!
Although a "jumping" main clock display and fast adjustment of the secondary clocks
does not occur anymore after having modified the synchronisation rate, it is
nevertheless recommended to refit the PPS standard or to let the manufacturer of the
GPS system activate at least a higher up-date rate.