Globalstar ST150M User Manual page 58

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of-location event. This track mode adds resiliency by utilizing two sources for movement verification.
9.1.14.3 Theft-Alert Mode
Theft Alert mode creates a geofence around the device after power-up.
If inside the geofence, OTA position messages are sent the same as in Normal Track Mode.
If outside the geofence, OTA position messages are sent more frequently at the in-motion interval.
9.1.14.4 Enabling/Disabling Track Modes
Track modes can be enabled and canceled/disabled via Track Mode AT commands.
9.1.14.5 Previous Track Point
Previous Track Point is a feature that helps compensate for any missed tracks by sending the delta latitude/longitude of the
last two positions at preset intervals. This makes it possible to re-construct a track up to two reporting intervals beyond the
initial reported location.
9.1.14.6 OTA Messages
OTA messages can include legacy standard and speed/heading messages, or Modular GPS Position messages.
Up to 64 bytes of user-defined payload can accompany OTA messages when utilizing the Mod Msg GPS Position Track OTA
profile (See Messages section).
9.1.14.7 Track Events
Track events can be sent via URCs to indicate asynchronous events that are occurring, and can be very useful for
debugging.
9.1.14.8 Non Maskable Track Mode
Non Maskable Track Mode is similar to regular Track Mode, except it is intended to be used like an SOS track mode, where a
priority 4 OTA message will pre-empt any and all messages in the transmit queue (See Transmit Queue section).
Non Maskable Track Mode contains its own modular message profile, or can be used with legacy standard and speed/
heading messages (see Messages section).
9.1.15 GPS MODULE
The GPS module can use the internal GPS chipset or leverage an external GPS via the set GPS position AT commands. The
GPS generates events that are used by the application's track mode.
9.1.15.1 Stale Time
GPS stale time is the amount of elapsed time allowed to occur while utilizing the current GPS fix in OTA messages that send
GPS positions.
If the stale time has elapsed, a new fix will be attempted. Requesting new GPS fixes consumes considerable power, so the
stale time can provide a balance for optimizing this tradeoff.
9.1.15.2 Fix Timeout
The GPS fix timeout refers to the maximum amount of time the GPS module will wait to obtain a position before giving up
and putting the GPS back into a low-power state.
9.1.15.3 Fix Settle Time
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