Sierra Wireless AirPrime WP75 Series, Справочник по командам AT

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GNSS Commands
Rev. 6 Oct.18 Proprietary and Confidential - Contents subject to change 203
!GPSTRACK Initiate local tracking (multiple fix) session
Initiate a local tracking session comprising a specific number of position fixes taken at
regular time intervals.
Password required: No
Reset required to apply changes: No
Persistent across power cycles: No
Usage:
•
Execution: AT!GPSTRACK = <fixType>, <maxTime>, <maxDist>, <fixCount>,
<fixRate>
Response: OK
or ERROR CODE = <value>
OK
Purpose: Initiate a series of time-limited position fixes.
•
Query List: AT!GPSTRACK=?
Purpose: Return supported <fixType>, <maxTime>, <maxDist>, <fixCount>, and
<fixRate> values.
Parameters:
<fixType> (Type of fix to establish)
•
1=Standalone (not supported by a mobile station)
•
2=MS-based only
•
3=MS-assisted only
<maxTime> (Maximum time to wait for satellite information)
•
Valid range: 1–255 seconds
<maxDist> (Requested accuracy of fix)
•
Entered in decimal format
•
Valid range:
•
1–4294967279 meters
•
4294967280=No preference
<fixCount> (Number of position fixes requested)
•
Valid range: 1–1000 (1000—Take a continuous series of position fixes)
<fixrate> (Amount of time to wait between fix attempts)
•
Valid range: 1–65535 seconds
Failure conditions:
The request fails if the tracking session fails to initiate.
If the request fails, the message ERROR CODE = <value> is returned. See
Table 8-3 on
page 210 for a list of error codes.
Note: The ‘time to first fix’ may require more time than subsequent fixes, if almanac,
ephemeris, or location data needs to be updated. (Almanac data is valid for 3–4 days,
ephemeris for 30–120 minutes, and location data for 4 minutes). To avoid a timeout error
(time spent > <maxtime>), your application could precede the
!GPSTRACK
call with a
single position fix (
AGPSFIX
) with a greater <maxTime> value.
(Continued on next page)
Table 8-2: GPS Command Details (Continued)
Command Description