• Radio Synchronisation:
The main transmitters in europe are located in: United Kingdom (MSF), France (France Inter) and Germany (DCF). Signals are in Local time and contain a complete message: Hour, minute, second, day of the year, day of the week, month, year, Summer/Winter changeover.
Bodet slave clock receives the time message, checks it, and compares it to its internal clock. If there is a difference, it automatically resets the time. The clock operates on the internal time base in case of radio signal interruption.
The radio synchronisation provides absolute accuracy and automatic summer/winter changeovers.
Today, most of the clock systems are equipped with a radio antenna
• GPS Synchronisation:
All over the world, time synchronisation can be ensured via a network of 24 satellites part of the GPS system. A specific antenna receives these timing message in GMT* time. Good reception of three satellites is sufficient for accuracy greater than one microsecond.
The GPS antenna receives the time message every second, decodes it and sends it to the master clock.
* GMT: Greenwich Mean Time. GMT is World Time and the basis of every world time zone which sets the time of day and is at the centre of the time zone map. GMT sets current time or official time around the globe.
Note : A standalone analogue or digital clock can be Radio synchronised only.