Sierra Wireless MC8775 Reference Manual page 131

Table 8-2: GPS command details (Continued)
Command
!GPSTRACK = <fixType>,
<maxTime>, <maxDist>,
<fixCount>, <fixRate>
!GPSTRACK=?
Supporting Mini Cards:
•
MC8775V
•
MC8780 / 81
•
MC8785V
•
MC8790 / 91
•
MC8791V
•
MC8792V
Note: This command is not
password-protected.
Rev 2.9 Oct.08
Initiate a local tracking (multiple fix) session
This command initiates a local tracking session comprising a specific
number of position fixes taken at regular time intervals.
Usage:
•
AT!GPSTRACK = <fixType>, <maxTime>, <maxDist>, <fixCount>,
<fixRate> initiates a series of time-limited position fixes.
•
AT!GPSTRACK=? returns 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)
•
0–255 — Number of seconds to wait
<maxDist> (Requested accuracy of fix)
•
Entered in decimal format
•
0–0xFFFFFFEF—Accuracy (in meters) requested for the fix
•
0xFFFFFFF0—No preference
<fixCount> (Number of position fixes requested)
•
1–999—Number of position fixes to perform.
•
1000—Take a continues series of position fixes.
<fixrate> (Amount of time to wait between fix attempts)
•
0–1799999—The number of seconds to wait between position fix
attempts.
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 139 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 (!GPSFIX) with a greater <maxTime> value.
Example:
AT!GPSTRACK=1, 15, 10, 20, 60 requests a series of 20 standalone
position fixes to 10 meters accuracy—fixes are taken every 60 seconds.
(Continued on next page)
GPS Commands
Description
131