User's Guide

Model: VSM3
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Positioning Universal, Inc. - Confidential & Proprietary
4 Tracking Behavior Summary
VSM3 applications address the needs of typical vehicle and asset tracking. Variations in
functional behavior for specific applications is controlled via parameters in the settings
file.
4.1 Power State Reporting
The VSM3 can be configured to report power up and rebooting behavior in a variety of
ways depending on what is desired. Cold Boot, Warm Boot, and first GPS Acquisition
are reported if so configured following Power Up events, power cycling, commanded
reboots, and configured periodic reboots. In addition, there is an option to report a Stop
event following a reboot of a non-moving device to address some customer needs to
ensure that the corner case of a reboot occurring at the end of a trip doesn’t result in an
error in trip or idle reporting by the server.
If the device is equipped with a backup battery, then it will also report Power
Disconnected and Power Connected events when primary power is removed and restored.
4.2 Ignition and Virtual Ignition
The VSM3 power harness includes an input which is normally used to detect ignition
status. This should be connected to a source on the vehicle or asset that provides a
voltage only when the ignition is in the ON state. When connected, this provides the
device with clear indication of when the ignition changes state (ie ignition is turned on or
off). The device reports these events and uses them to enter and leave “Moving” state. A
debounce value can be applied to the ignition signal. Debounce in this application means
a minimum dwell time of the change in ignition state before the state changes. This is
intended to avoid multiple messages being generated when the key switch in a vehicle
may generate multiple transitions during the starting sequence.
There are cases when an Ignition signal is not present, but it is desired to detect and
change the state of the device. These include simple installations without a hardwired
ignition line, towing of vehicles, or moving of assets that don’t supply an ignition signal.
Virtual Ignition is triggered by a sudden step up in voltage, consistent with starting a
vehicle. A minimum voltage threshold can also be specified to further qualify an ignition
event. A Virtual Ignition event is reported and the device enters Moving state.
If the device GPS indicates that a device is moving, it will enter Moving state and start
reporting based on the parameters set by the Settings file.
If a device without hardwired ignition comes to a stop of sufficient duration, a Stop event
is reported and the device enters Stopped state.