ABB AC 800F

8 Accessories
8-19
8.4.2 Functional principle of the GPS satellite radio clock
The time base of the satellite radio clock is synchronized by the GPS (Global Posi-
tioning System) satellite navigation system installed everywhere in the world. Satel-
lites are orbiting the earth twice a day at 20,000 km of height, on different paths and at
different angles. Each satellite is equipped with a high-precision atomic clock. The
GPS receiver receives the orbit positions and a GPS world time from as many satel-
lites as possible. This allows to determine the exact position of the receiver (location).
Once the position has been determined, the travel time of the received GPS world
time signal from a satellite can be determined. After conversion of the GPS UTC and
regional adaptation, the local time is available with high precision.
The connection of the satellite radio clock to the AC 800F and the time synchroniza-
tion is done system-wide, as for the DCF77 radio clock (see Section 8.3).
8.4.3 GPS satellite radio clock deliverables
Normally, the components listed below are needed for connecting a GPS satellite ra-
dio clock to the AC 800F:
Qty. Component Order code
1 Stand-alone 6841GPS system with LC display,
keyboard and power supply in half 19" rack
FG6841G11
1 Active GPS antenna with 25 m standard cable for flat roof
and wall mounting
FG4490G0
1 Indirect lightning protector for GPS antenna FG4495G0
Note that the component names and order codes may have changed.
Please contact Hopf for details.
If the distance between the GPS system and the external antenna should be longer
than 25 m, please contact the company Hopf who will then offer you the appropriate
components for your application. The clock in the ordering example listed above is
equipped with an outdoor antenna and a 25 m antenna cable.
The 19" model can be mounted to the same support rails as the AC 800F. A space-
saving model with half 19" mounting width is also available.
An external antenna is always required for satellite radio reception. It is therefore rec-
ommended to order the appropriate lightning protection module, too. Please contact
Hopf for the configuration meeting your requirements and for further details.