User's Manual

DRAFT TrimTrac 1.5 Technical Manual v0.3ab 25
Application Scenarios
Introduction
The TrimTrac 1.5 is both elegant and powerful in its simplicity. How to best configure it
for any given application, however, may not always be intuitively obvious. The intent of
this section is to provide operational insight and specific configuration suggestions based
on different application environments.
General Considerations
When deciding how to best configure the TrimTrac 1.5, consider the following:
1. What is the expected frequency and duration of motion?
2. How often should the unit compute a new position fix while in motion?
3. How often should the unit report while in motion? While stationary?
4. How sensitive is the end-user application to power consumption, recurring
communication costs, or both?
Motion Profile
How frequently the TrimTrac 1.5 is moved and how long it remains in motion
will effect unit operation. For instance, a unit that is expected to make many short
trips per day will generally benefit from having a higher number of position fixes
than one that moves only a couple of times per day but remains in motion longer
during each trip.
Fix Density While in Motion
In general, if there are going to be multiple trips per day, setting the DELAY
Timeout, T4, to 25% of the expected duration of each trip will provide a
reasonable fix density. For instance, if the average time of each trip is
approximately one hour, setting DELAY Timeout, T4, to 15 minutes (900
seconds) has proven to be a good balance between fix density, power
consumption and, if transmitted, communication costs.
The maximum fix density one can expect to get from the TrimTrac 1.5 is one
position fix every 3 to 5 minutes. While this is probably not sufficient for some
dispatch, intercept and real-time fleet management application, a fix density of 3
to 5 minutes is more than acceptable for an extremely wide range of less real time
critical applications.
Reporting Frequency
The rate at which the TrimTrac 1.5 computes new position fixes needs not be the
same rate at which it transmits those logged positions to the server application.
While the device is in motion, the DELAY Timeout, T4, setting largely
determines the frequency at which the TrimTrac 1.5 will attempt to compute and
log a new position fix.