User`s manual

Alcorn McBride Digital Video Machine DVM-7400 User’s Manual Rev 1.5

GPS Control

Overview

The Digital Video Machine can automatically trigger videos whenever it enters into a

predetermined geographical area. With this feature you can easily design a “No

Operator-Intervention Required” A/V system on a tour bus or tram that automatically

plays pre-recorded spiels or videos whenever it enters a specified area.

Enable the GPS mode

of operation by turning

DIP switch #2 of the

2-key DIP switch

block OFF (UP).

In GPS Mode, the

DVM will not accept

normal serial

commands.

The DVM accepts a

standard NMEA-0183

data stream at default

4800 baud. You can

change the baud rate

using the BR

command in your

GPS playlist.

The DVM accomplishes this by reading a data stream from a GPS (Geographical

Position Satellite) sensor. This sensor is often in the form of a “GPS Mouse” or pod

that outputs a serial data stream containing Longitude and Latitude data obtained

from orbiting GPS satellites, and normally connects up to a serial or USB port on a

laptop computer running mapping or direction-finding software. In the case of the

DVM, the sensor connects up to the 9-pin serial port.

The Longitude and Latitude data supplied by the GPS sensor is compared to

geographical points stored in a GPS playlist. Each entry in a GPS playlist contains a

command supported by the DVM’s Command Protocol as well as GPS coordinates

that are associated with that command. When a GPS sensor is connected to the

DVM and a GPS Playlist is active, the incoming coordinates are compared to those

listed in the GPS Playlist. When a match is found, the command is executed.

GPS Playlists can be easily created using a Alcorn McBride’s free Windows

application called GPS Builder.