XT55 AVL Software Instructions User’s Guide
Confidential/Preliminary s
mo b i l e
XT55_avl_ug_V01 Page 13 of 20 15.03.2004
3 Tracking

3.1 History function

When receiving valid GPS protocols, the module XT55 is capable of saving up to 10,000
GPS protocols in its history memory.
When the memory space has been used up, the oldest protocols will automatically be
deleted to make space for new incoming data.
Figure 11 shows a logical flow chart, for a better understanding how the module XT55 saves
history data.
Position Fix Filter
Fix Position
enable ?
No
No
No
No
Yes
Yes
Yes
Yes
END
Store data on
Flash memory
> 10 Km/h ?
>180 sec.?
*) X >= 3;
X*
SV solution?
No
Yes
History enabled
Time
Speed
Figure 11: History Filter