DCT e-track, Руководство пользователя, Страница: 78 / 212

4.5. *EVENT MACHINE
the
GS
message.
•
Time Windows’ signals with the
GT
message: The signal is true
whenever the actual date/time lies between the minimum and
maximum date/time defined with the
GT
message.
•
Time and Distance’ signals with the
TD
message: The signal
is true when the Time And Distance condition configured with
the
TD
message is met. This signal has the particularity that it
is immediately set to false after a complete evaluation of all the
events. This creates a “periodic” sort of signal which is suitable
for a Time And Distance report.
An example of using these messages to define a signal:
Defining the speed signal
S06
to be true whenever the traveling speed Example
exceeds 55mph and false whenever the speed is below:
>
SGS0610550
<
Now the speed signal
S06
can be used on an event’s definition to
generate a report every time the vehicle exceeds 55mph :
>
SED33NT3;S06+
<
We just defined event 33 to send an ET report to DA 3 every time
the
S06
signal switches from false to true , that’s what the + sign
does. The report will only be generated once. In order for the event
to trigger again the
S06
signal has to become false first and then true
again. This means that the speed excess is going to be reported every
time the speed goes from anything less than
55mph to a larger value
but not every time the speed remains at the larger value.
4.5.5 Examples
Some examples about the use of the event machine are presented
next.
For complete examples containing both the Event Machine
and the other parameters necessary to get the unit working refer to
the
Scenarios and Examples chapter. To understand the events’ con-
figuration format refer to the
ED
message on the TAIP reference.
Creating an event to detect when e-track
TM
leaves a defined region: Example
When an unit is outside the perimeter defined by the polygon that
defines a region, the corresponding region’s signal is set to false. To
generate an event whenever the unit leaves the region the region’s
signal has to be monitored for the
true to false transition (this is
done with the minus sign on the event’s trigger):
>
SED24NV7;R26-
<
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