System Planning Corporation GTLITEV3 Manuale Utente

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GlobalTrak ™ 
GT Lite Operation and Maintenance Manual 
 
Door Sensor (optional) 
The door sensor is a digital input to the device.  If the input is open or floating, the door state 
is reported to be open.  If the input is connected to ground, the door state is reported closed. 
The sensor output is constantly monitored and edge triggered, even when the GT Lite is in its 
lowest power state.  Following first indication of a possible change of state, the sensor is 
sampled for an additional number of seconds, and an event is declared only after all 
consecutive readings indicate such.  For a door open or closed event, the GT Lite immediately 
generates a message and sends to the IMB.  The door sensor is immediately re-armed after 
any event. 
The sensor can be enabled or disabled over-the-air through the GSM network or locally. 
The door sensor can be either externally wired or mounted internal to the GT Lite.  The 
external sensor can be any contact closure switch between the input and ground.  The 
internal door sensor is a reed-based, magnetic proximity sensor, implemented as a single 
pole, single throw (SPST) normally open contact switch.  Circuit is closed when the actuator is 
within 1.5”.  The circuit is open when the actuator is outside of 1.7”.  This sensor is placed at 
the edge of the enclosure for applications where GT Lite is mounted on, or next to, a door. 
Temperature Sensor 
The sensor range is from -40°C to +85°C, with accuracy within <1°C across this range. 
The sensor output is be sampled by the low power controller at a rate of 1 reading per 
second, even when the GT Lite is in its lowest power state.  The measured value is compared 
against a stored upper and lower threshold, and when either is crossed, an event message is 
to be immediately generated and sent to the IMB.  The sensor is re-armed after the sensor 
level returns from the alarm state.  At the point where the sensor level crosses the threshold 
back to a typical level the sensor alarm is once again active. 
All thresholds are user programmable, changeable over-the-air through the GSM network or 
locally. Also the thresholds can be disabled, such that no event message is generated. 
Mount Sensor 
The sensor is a reed-based, magnetic proximity sensor, implemented as a single pole, single 
throw (SPST) normally open contact switch.  Circuit is closed when the actuator is within 1.5”.  
The circuit is open when the actuator is outside of 1.7”. 
The sensor output is constantly monitored and edge triggered, even when the GT Lite is in its 
lowest power state.  Following first indication of a possible change of state, the sensor is 
sampled for an additional number of seconds, and an event is declared only after all 
consecutive readings indicate such.  For any change in mount status, the GT Lite immediately 
generates a message and sends to the IMB.  The mount sensor is immediately re-armed after 
any event. 
The sensor can be enabled or disabled over-the-air through the GSM network or locally. 
The location of the magnetic sensor located inside the GT Lite cover is marked.  The actuator 
is located in line with the sensor making on the GT Lite cover.  The actuator and GT Lite 
enclosure are to be mounted separately so if the GT Lite is removed, the actuator stays. 
  Prepared:  R. Straz 
Date: July 25, 2007 
 
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