DCT Antares SB, User Manual

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6.25. (TD) TIME AND DISTANCE SIGNALS CONFIGURATION
6.25 (TD) Time and Distance signals configuration
Qualifiers :
Q
,
S
,
R
The Time and Distance signals are set by its corresponding Time and Dis-
tance counter which is a counter that follows a Time and Distance criteria.
This criteria allows to create a counter that does not follow a time or dis-
tance criteria independantely from each other, instead, combines these two
variables to generate an intelligent trigger to be used for a more efficient
vehicle tracking.
These signals are immediately reset by the processor after
being evaluated in order to allow future triggers .
Time and Distance criteria
The main purpose of this counter is to control the reporting frequency ac-
cording to the vehicle’s displacement. So that the unit increases the report
frequency when the vehicle is moving (accumulating traveled distance) and
decreases it when the vehicle is not moving. This is more efficient than
having the unit report by a
time-only criteria were almost all of the reports
triggered when the vehicle is not moving are not relevant.
The counter can also be configured to follow a time-only criteria.
To do so, set the Distance Threshold parameter to
0
and the unit
will only use the Minimum Report Time as trigger.
Note:
How does this criteria works ?
First, the signal has to be triggered by a distance threshold that tells the
activate its associated TD signal whenever the accumulated distance exceeds
this value. This
distance-only scheme has two problems:
1. What if the vehicle goes too fast and/or the distance threshold is low
?. It will set the signal too frequent.
2. What if the vehicle moves too slow and/or the distance threshold is
large ?. Or worse, what if it does not move at all?. It will activate
the signal very few times or may never activate it.
To solve this problem the distance-only trigger is improved with a Time
and Distance trigger that adds two controlling parameters for the Dis-
tance threshold . These parameters are the Minimum Time and the Maxi-
mum Time .
The Maximum Time takes control of the signal when the unit has not ex-
ceeded the Distance Threshold for a long time. So this value ensures a
minimum triggering frecuency. One way to see this parameter, is that this
time will be the signal activation period when the vehicle is stationary.
The Minimum Time takes control of the signal when the unit exceeds the
Distance threshold . Assuring that even when the unit is exceeding the Dis-
tance threshold it will not activate the signal too frequently, no more frequent
than the configured minimum time value. One way of seeing this parameter
is that this time will be the report period when the vehicle is moving too
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