This user manual introduces the use of XT55 AVL Siemens Cellular Engine
The XT55 module integrates GSM, GPRS and GPS functions and includes Automatic Vehicle Location (AVL) software. This guide describes the module’s hardware configuration, software interface, and how to configure and evaluate the XT55 AVL firmware using a Windows HyperTerminal.
It also provides detailed information on command syntax, NMEA output messages, power‑on/off procedures, and an example application with a Li‑ion battery pack and GSM antenna. Technical specifications such as average supply current are listed in the final tables.