Advisory Legend


Advisory Legend

The *.LEG legend file defines the geographic constraints within which the advisory will be executed. The region where an advisory will be executed is a geographic region described identically to that of a map. Advisories are further defined by a course, between 0 and 360 degrees, and a course range, between 0 and 180 degrees, (also described in the *.LEG file) for which the advisory is executed. You can therefore define, for example, two advisories for a given place on a highway; one which is displayed when a vehicle is moving in one direction, and the other when the vehicle is moving in a different direction.

Having given a short description, we now list the different rules or qualifiers which may be specified in an advisory legend:

Geographic region;
Course and Course Variance;
Event ID; and
Specific Vehicles.

Reference Vehicle ID: An advisory can also contain a reference vehicle ID qualifier. If the reference vehicle ID is present, only the vehicle that matches the reference vehicle ID can cause the advisory to execute.

Filename: This is the name of the advisory. A default name is placed in this field (date time stamp). You can change this name to be eight characters with the .adv extension. If there is an associated image file, you must use the image filename for the advisory filename (e.g. AIRPORT.ADV opens AIRPORT.JPG).

'Always open this advisory...': This is used to always open an advisory when it is triggered. This is important for events. Any other advisory will open and close on it's own. An event will sometimes open and then just stay opened forever. When a vehicle enters an advisory with a region, the advisory opens. When the vehicle leaves a region, the advisory closes. If an advisory is opened and the operator closes the advisory window, the advisory stays closed until it is opened by 'Advisory... Reopen Closed Advisories...'. This way an operator can disable a particular advisory so it doesn't keep opening. If 'Always open this advisory...' is selected, the advisory will always open, even if it was closed by the operator. This is useful for events, since sometimes the operator will close an event advisory once it has been acknowledged.

Not Location-Sensitive (can trigger anywhere): This is for vehicle events (vehicle inputs like door open, emergency panic button, etc...). This allows advisories without map boundaries (it covers the entire world). This way, a vehicle does not have to enter a particular region to trigger the advisory. It will be triggered by the Event ID. If you are creating region advisories on the map, ignore this field (leave unchecked).

Course and Course Variance: RASTRAC qualifies an advisory's course, based on a vehicle's current course, by determining whether your course falls within the course range defined as follows:

Course Lower Bound = *.LEG Course - *.LEG Course Variance;
Course Upper Bound = *.LEG Course + *.LEG Course Variance.

Under this definition, the defined course variance acts as a "+/-" range above and below the defined course.

Event ID: RASTRAC also qualifies an advisory's event ID, based on a vehicle's current event ID(s), by determining whether the advisory's trigger event is active for the vehicle.

What is an Event?
This question is best explained by first answering the question, "What is an advisory"? An advisory is empirically described as "something that happens in RASTRAC when something special happens in the life of a vehicle". That is, the action of a vehicle entering a specific geographic region constitutes a special event. However, that event may not really be special unless the vehicle's course is within a specific range, i.e., he's traveling in a special direction. That's why advisories contain course qualifiers.

The key message of the above paragraph is that advisory regions are nothing more than "rules" that we use to define what is and what is not a "special event" in the outside world.

It's not difficult to define a geographic region and course, and, thereby, say that a vehicle should be annunciated when it enters and/or leaves the region. However, it is much easier to simply let the mobile unit tell us when a special event is happening. The action of a mobile unit annunciating himself is the definition of an event in the context of RASTRAC.

Beyond defining how events (which are identified by Event IDs) originate, it is of equal importance that we have some way of expressing the existence of such events within the RASTRAC software environment. If you define an advisory which covers the entire earth, whose course range covers the entire compass rose, and which contains a specific event’s ID, then the advisory will execute whenever any vehicle on the earth notifies us that that particular event is occurring. The advisory database serves to notify us of special external happenings in the outside world, whether they be associated with geography, direction, or simply predefined abstractions (i.e. incoming "Event IDs").

Examples of externally annunciated events are panic buttons, door closures, tailgate-down indications, or any other activity in the vehicle which can activate one of the vehicle modem’s sensor lines.

See also Define Advisory