System Planning Corporation GTLITEV3 Manuale Utente

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GlobalTrak ™ 
GT Lite Operation and Maintenance Manual 
 
Over-the-Air Programming 
The GT Lite firmware for both the main processor and low power controller are changeable 
wirelessly, with full code load capable through GPRS.  The method shall includes an 
appropriate level of security.  GT Lite authenticates OTA Upgrade messages first, then 
accesses a password protected repository to download code.  
ZigBee Mesh Network 
At a configurable interval in hours starting at 0:00 GMT, the ZigBee Mesh Network will wake 
to transmit pending Event LM’s to nodes with external communication (as indicated by the 
Connectivity Flag).  The network will remain awake for a configurable time period to ensure 
every node has ample time to enumerate the network and transmit data.  Nodes with an 
external network will take the data received via ZigBee and pack an LM by appending the last 
valid  GPS  fix.    The  message  will  then  be  placed in the queue for transmission on next 
transmission attempt. 
DSP:  Operations from the M100 
ZB:  Operations from the ZigBee module 
 
1)  DSP:  Wake ZigBee module 
2)  DSP:  Send connectivity flag status to ZigBee module 
3)  ZB:  If connectivity flag = True 
a)  ZB:  Wait X seconds for all nodes to wake 
b)  ZB:  Declare node as Coordinator 
c)  ZB:  Enumerate network 
d)  ZB:  If no network is available 
i)  ZB:  Go to sleep 
ii)  DSP:  Return to previous function 
e)  ZB:  If network is available 
i)  ZB:  Listen for ZMT seconds for children to send messages 
ii)  ZB:  If ZigBee messages received 
(1) ZB:  Pass messages to M100 
(2) ZB:  Go to sleep 
(3) DSP:  If GPS mode = Previous valid 
(a) DSP:  Repack LM with last valid GPS fix 
(4) DSP:  Place messages in queue with Message Identifier = LZ 
(5) DSP:  Attempt transmit during next scheduled transmission or transmission of events 
(6) DSP:  Return to previous function 
iii)  ZB:  If no ZigBee messages received 
(1) ZB:  Go to sleep 
  Prepared:  R. Straz 
Date: July 25, 2007 
 
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