Rover-X User Manual Version 1.0
17
Rover-X Tasks
The Rover-X
’s behavior is based on multiple timed
tasks. Understanding how these tasks
interact is necessary to properly use the Rover-X in the field. There are three major timed tasks:
GPS
The Rover-X will search for the GPS constellation and get a location fix based on this interval.
Any successful GPS fixes will be queued for the next Iridium (SBD) transmission.
The Rover-X
’s internal clock will also be set and adjusted based on the GPS network. The GPS
interval will execute before the SBD interval if they are scheduled for the same time.
SBD (Iridium)
The Rover-X will attempt to communicate with the Iridium Gateway based on this interval. If
the Rover-X successfully registers with the Iridium Satellite Constellation, Rover-X will transmit
any messages queued to be sent to the user. Once this is finished it will receive any queued
messages from the Iridium network, implement them, and respond, provided the proper unlock
code is received with those commands.
Iridium also employs a retry scheme, in the event queued messages are not successfully
transmitted. For each scheduled Iridium task, two retries are possible if necessary:
•
Two minutes after the scheduled Iridium task ends, if a message was not sent.
•
Five minutes after the first retry task ends, if a message still has not been sent.
•
If a message still has not been sent after both retries, it is queued for the next regularly
scheduled Iridium task.
TLT
The tilt sensor of the Rover-X will take regular readings to determine the orientation of the
device. If the Tilt function is enabled in the Switch menu, consecutive inversions prompt the
device to transition to the Inverted alarm mode, or out of that mode if readings show the
device has returned to an upright position.
The tilt sensor is also used to choose the correct GPS and Iridium hardware to use when either
of these tasks run, regardless of the Tilt alarm setting.
