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4.5. *EVENT MACHINE
4.5 *Event Machine
The unit’s reporting is controlled by an Event Machine which constantly (*)Essential configuration
evaluates user defined events. These events allow the user to create a re-
porting schema and functionality controlled by
triggers and actions . Events
can be consulted or configured at any time with the
ED
message throughout
the TAIP console, enabling the user to alter the Event Machine parameters
at any time locally or over the air .
Up to 50 events may be defined on the unit. These events are evaluated
on a sequential order based on the event’s ID. This means that lower IDs
are evaluated first. Having this in mind an event’s ID may be relevant if its
trigger depends on other events’ signals and/or on other events’ user-defined
actions. The whole 50 events’ evaluation is performed at a 1 second rate.
This section examines the events’ components: triggers and actions . Then
it gives an overview of the events’ definition to complement the TAIP refer-
ence. Finally explains one of the most important components of the events’
triggers:
Signals .
The Event Machine , based on user’s configuration decides what,
where and when to send a report and/or execute an action, but
it is not all of the configuration needed by the unit. When
the user starts configuring the Event Machine , it is assumed that
he has already defined the Destination Addresses an their corre-
sponding Destination Points as described on the previous sections
of this chapter. Enabling the unit on the GSM/GPRS network is
also required.
Note:
4.5.1 Triggers
A trigger is determinated with the logical combination of several situations
(also called signals). A logical combination is basically an equation (specifi-
cally: a boolean equation) that combines signals (situations) with the logical
operators
AND
,
OR
and
NOT
.
Combining situations with operators:
Example
A vehicle going at or over 60mph is a situation, let’s call it situation
S
.
This situation may be true or may be false , there are no other possibilities.
These kind of situations that can only take two possible values, true or false ,
are said to be of boolean nature. Let’s add another
boolean
situation: A
vehicle located within some cities’ perimeter. This again is a two-value-only
situation. Let’s call it P.
How can we combine these two situations to create a third complex situation
?. We can do so with logical operators. For example, let’s create a third
situation C that is only true when the other two situations are also true.
For this we use the
AND
operator in the following form:
C = S AND P
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