User's Manual

DRAFT TrimTrac 1.5 Technical Manual v0.3ab 14
POSITION_REP will have the TriggerType set “2=Alert”, the position that first
triggered the boundary crossing notice and the Geofence Status field will be set
“1=Violation”. The RESP_GEOFENCE_CONFIG message will denote which
particular geofence had a boundary crossed.
Geofences and GPS Fix Rate
Depending upon how strictly geofences must be enforced, it may be advantageous
to set the GPS Fix Rate to “1=GPS 1Hz”. Geofences are enforced based upon the
most recently computed GPS position. If the TrimTrac 1.5 only computes a new
fix each time it enters the FIX State, then the latency in reporting a geofence
violation is extended to the time it takes the TrimTrac 1.5 to cycle through the
entire state machine.
If a more vigilant enforcement of the geofence is desired, then the GPS Fix Rate
can be increased to once per second. This would afford more continuous
enforcement of the geofences, albeit at the expense of power consumption, and
near real time reporting of violations.
Geofences and Automatic Message Log Dump
GSM coverage may or may not be available throughout the geofence area and
beyond. This means that a device may be able to slip out of and then back into a
geofence area undetected by server, at least until GSM coverage became
available. If a geofence violation had occurred while there was no GSM
coverage, the device will maintain keep the Geofence Status flag set as a violation
until reported to the server application whether not the device is inside or outside
the geofence area at the time the message is transmitted.
Before the device is able to transmit a message with the geofence violation, the
TrimTrac 1.5 may have traveled well beyond the geofence area while outside
GSM coverage. If the Automatic Message Log Dump feature is enabled, then the
device will not only transmit the message noting the geofence violation when
GSM coverage becomes available, but it will also transmit all positions logged
while traveling in violation of the geofence outside GSM coverage. In so doing,
the server application will not only know that a geofence violation had occurred,
but also where the device traveled in the mean time.
Scheduled Hours of Operation
This feature establishes daily consecutive hours during which use of the monitored asset
is considered either “authorized” or “unauthorized”. In so doing, you establish when no
routine messages are to be transmitted. In effect, the Schedule Hours of Operation
selectively sets the Report Delay Flag in accordance with a daily schedule. (Note: This
feature should not be confused with Scheduled Reporting Mode or the Runtime Meters.)
Before the Schedule Hours of Operation feature can be activated, you must define a daily
start time (relative to UTC) and how long each workday lasts. You must also specify