User's Manual

GlobalTrak ™ GT Lite Operation and Maintenance Manual
Condition Blink Code
Boot Dash Dash
Acquiring GPS Dash Dash Dot
Successful GPS Fix (2D or 3D) Dot Dot Dash Dash
Unsuccessful GPS Fix Dash Dash
Successful transmission
Dot Dot
Unsuccessful transmission
Dash Dash
Auxiliary Serial Port
An auxiliary serial port is available on GT Lite. This serial port can be selected as an external
RS232 port or an internal UART through a software controlled switch. The switch selects
between an RS232 driver to the Power I/O connector and a UART to the internal expansion
header. Serial data is carried on the Transmit (TX) and Receive (RX) lines. The specifications
are as follows (all are software configurable):
a) Baud Rate: 9600 up to 115200 bps
b) Stop Bits: 0, 1, 2
c) Parity Bits: odd, even, none
Use of the auxiliary serial port requires additional software on the device and IMB for proper
behavior.
Power Management
The main processor and low power control are provided with power control of the various
subsystems. This includes the GPS receiver, the onboard sensors, and the cellular modem.
This high degree of control is needed to enable very low power modes, thus reducing battery
power requirements.
Main Battery Switch
The exterior key switch enables complete disconnection of the internal batteries from the
electronics, to preserve shelf life and minimize battery recharging / replacement events. The
switch is keyed to reduce the opportunity for deviant or accidental behavior resulting in
deactivation of the GT Lite.
Battery Level Reporting
The remaining power is reported by the GT Lite. A voltage vs. capacity curve is stored on the
GT Lite. GT Lite uses this curve to determine remaining capacity.
While external power is applied, the battery will be reported as maximum capacity and
external power will be reported as present.
Real-Time Clock Function
The GT Lite maintains date and time information even when in its lowest power state. The
clock is updated following a successful GPS location estimate as well as through the GSM
network.
Prepared: R. Straz Date: July 25, 2007 Page 22 of
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