User's Guide

Model: VSM3
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Positioning Universal, Inc. - Confidential & Proprietary
4.3 Absolute G detection
Absolute G is an algorithm that detects low frequency changes in the resultant vector of
the acceleration reported by a MEMs accelerometer. This permits the device to detect
things like vehicle acceleration without a GPS fix. Higher frequency activity like normal
vibration, doors opening or closing, are filtered out. Exceeding the Absolute G threshold
specified in the Settings file will wake a device and put it in the Stopped state.
4.4 Moving State
A device enters Moving state either due to detection of a hardwired Ignition signal, an
increase in the supply voltage, detection of movement by the GPS, or an “Absolute G”
detection. While in Moving state, the device reports periodically as configured. Both
primary Moving interval reports with full data, and “minor intervals” (with only latitude,
longitude, speed, and time) for data compression can be reported while in Moving state.
4.5 Stopped State
A device enters Stopped state when it wakes from Sleep, or when it exits Moving State
due to an Ignition OFF signal, or detection of a Stop event.
4.6 Sleeping State
A device enters Sleeping state from Stopped state when all of vibration, GPS movement,
and primary voltage are quiescent for a sufficient duration. The qualifying duration of
quiescence, and the degree of sleep encountered, are controlled by parameters in the
Settings file.
4.7 Heartbeat Reporting
The device reports a Heartbeat message at an interval specified regardless of state. If the
device is sleeping when the Heartbeat timer expires, it will wake up and generate the
Heartbeat message. Whether the device attempts a GPS fix for each Heartbeat message
can be specified.
4.8 Driver Behavior
Driver Behavior reporting is still in development and is not recommended for use at this
time.
Driver Behavior reporting generates alerts based on detection of g values that exceed
thresholds specified in the Settings file. The direction of the acceleration determines
whether the event represents Hard Acceleration, Hard Braking, or a Swerve.
4.9 AGPS
Where the inbound server has the capability, Assisted GPS is employed if a GPS fix is
not available following the detection of an Ignition ON or Virtual Ignition event.