Trimble Outdoors thunderbolt 64057-00-eng Benutzerhandbuch

Trimble ThunderBolt E GPS Disciplined Clock User Guide     

Setting up and Running the ThunderBolt E     

If the host has not uploaded a reference position, or if the module has been moved 
more than one to two kilometers since its last position, the GPS module automatically 
conducts a position survey at startup. By default, the GPS module averages 2000 
position fixes before entering the clock-only mode. The host system can adjust the 
survey period using packet 0x8E-A6. While the GPS module is performing its survey, 
the accuracy of the timing outputs will be degraded.

To upload an accurate reference position, use packet 0x31 (

), or packet 0x32 (

): The 

reference position is stored in EEPROM (Electrically Erasable Programmable Read-
Only Memory) and is retained during power loss. When a reference position is stored 
in EEPROM, the GPS module bypasses the position survey procedure and enters 
clock-only mode. If you move the antenna, you must send packet 0x8E-45 to clear the 
position stored in EEPROM: The GPS module then initiates a self-survey, unless the 
host uploads a new position using packet 0x31 or packet 0x32. 

To store the reference position from the self-survey procedure in the EEPROM, send 
packet 0x8E-4C to the receiver. Alternatively, you can configure the ThunderBolt E to 
automatically save the position using packet 0x8E-A9.