avl_time_state

D2Sphere and Device Time Managment

Timeformat

current time formats are in use:
- International Atomic Time (TAI)
- Coordinated Universal Time (UTC)
- GPS time (GPST)
Time difference by leap seconds
- (TAI − GPS = 19 seconds)
- (TAI - UTC = 37 seconds)
all devices use 'GPS time' GPST as base (https://en.wikipedia.org/wiki/Global_Positioning_System#Timekeeping)
ONLY Front End GUI must use Time Zone offset - backend and device time must stay UTC/GPST.

AVL Time State


sequenceDiagram
    participant SystemTime
    participant LastValidPosition 
    participant RTC 
    participant GNSS 
    participant UserTime
    
    LastValidPosition ->> SystemTime: load last valid time and timestamp not older then build date
    RTC ->> SystemTime: load RTC time if time valid flag and timestamp not older then build date
    GNSS ->> SystemTime: load GNSS time if time and date valid and timestamp not older then build date
    GNSS ->> RTC: set RTC time if time and date valid and timestamp not older then build date
    UserTime ->> SystemTime: set Time via $PFAL,Sys.SetTime,dd.mm.yy,hh:mm:ss
    UserTime ->> RTC: set Time via $PFAL,Sys.SetTime,dd.mm.yy,hh:mm:ss
    SystemTime ->> LastValidPosition: save last Valid pos and time $PFAL,GPS.Nav.SaveLastValid

D2Sphere Response to 'non' correct time in Login Field

AVL Time State

$PFAL:ID1,Sys.SetTime,06.07.2020,09:40:19;GPS.Nav.SaveLastValid

GPS.Nav.SaveLastValid is only sent to store on AVL the given time as default startup time
Sys.SetTime,06.07.2020,09:40:19 need to be parsed and used as time in UTC for any further data sent to D2Sphere