XT55 AVL User’s Guide
Confidential/Released
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XT55_avl_ug_V03
Page 6 of 37
28.06.2004
1 Overview of the document
The XT55 module, supporting GSM, GPRS and GPS features, contains the Automatic
Vehicle Location software application (AVL) which can be configured.
The Global Positioning System (GPS) is a satellite-based navigation system made up of a
network of 24 satellites placed into orbit. GPS satellites receive data to determine the current
position of the tracked vehicle.
The concept of the device is based on a simple implementation for a wide range of
applications with low costs and high flexibility. In particular it offers a fast development of
system solutions within the fields of:
•
Tracking
The vehicle to be tracked is fitted with the module XT55 including a GPS and a GSM
antenna. GPS satellites are continuously transmitting a radio message containing
information, including when the data was sent, which satellite sent it and the current
reliability of the system. The XT55, containing the AVL software, fitted in a vehicle
receives this information from at least 4 satellites and carries out the necessary
calculations to determine its current position.
•
AVL
The GPS receiver embedded into the XT55 module determines its current location,
speed and heading. These data can either be stored or directly transmitted to an
operating center. The terminal reports its position to the call center over GSM
communications network. The current position can be displayed on a PC/PDA in digital
maps which must be obtained separately.
Depending on the configuration, the device exchanges data with a server application (e.g.
mapping software, etc.). The module XT55 can be configured by the user via local RS-232
interface or via remote GSM (air link).
At the core of the system solutions mentioned above is a classical set-up with client-server
architecture. In this scenario, the module XT55 represents the so called mobile client (see
Figure 1).
The integration of the module XT55 requires a clear definition:
-
The characteristics of the integrated AVL software solution of the module XT55 as a
client of the user solution, and the possibilities for configuration.
-
The instruction command for communicating with the client as the main part of the
server application
This document intends to describe the module XT55 AVL firmware and how it can be
configured, including the description, which is based on the Windows
HyperTerminal
configuration (terminal emulator program). For the flashing process of the AVL software into
the module please contact Siemens AG for further information.
Furthermore, this document gives a detailed description of the instruction command,
providing information for setting up customized server applications for communicating with
the mobile client (XT55).
