Alcorn Mcbride AM-4, Hardware And Software Reference Manual

Page: 61 / 77

GPS Operation 55
Play
This is command normally associated with a specific geographical location and is executed
when the Longitude and Latitude locations specified in the corresponding columns are
matched. The Play command uses one Data column described here.
Data1 : The sound number of sound file name to be played.
Data2 : (Optional) The amount of time (in seconds) that the track will fade-in
Data1 and Data2
The Data1 and Data2 columns are used to supply additional parameters to commands. They
are described above with the specific commands to which they apply.
Latitude and Longitude
The Latitude and Longitude parameters specify where the command will be executed. This
data is entered by following the procedure described at the end of this section of the manual.
Direction
This is the heading, in degrees, of the direction of travel. North is 0 degrees and South is 180
degrees. The AM-4 will use the acquired direction to qualify a GPS trigger. The tolerance is
45 degrees (+/- 22.5 degrees). If you want the point to trigger independently of direction,
remove the direction parameter and the point will trigger no matter which direction you’re
going.
Tolerance
The amount of tolerance at which a particular trigger occurs for a programmed Latitude and
Longitude can be adjusted by specifying a Tolerance number. The pull-down menu provided
is shown here:
Longitude and Latitude data provided by the GPS sensor updates at one-second intervals (this
is a function of the sensor, and not the AM-4). As a result, you can “drive through” a desired
trigger point if the vehicle is going fast enough so that a matched GPS point is not received
within the one-second interval. Therefore, the faster the vehicle travels for a given point the
wider the specified tolerance must be. This menu allows you to specify the tolerance in either
meters or speed.