NEO-M9N - Integration manual
• After a valid position fix,
Tracking
state is entered and the
ONTIME
starts. In other words the
ONTIME
starts with the first valid position fix.
• Once the
ONTIME
is over,
POT
state is entered.
• In
POT
state the receiver continues to output position fixes according to the CFG-RATE-*. To
have maximum power savings, set the
ONTIME
to zero. This causes the receiver to enter
POT
state as soon as possible.
• If the signal becomes weak or is lost during
POT
state,
Tracking
state is entered.
• Once the signal is good again and the newly started
ONTIME
is over, the receiver will re-enter
POT
state.
• If the receiver cannot get a position fix in the
Tracking
state, it enters
Acquisition
state. Should
the acquisition fail as well,
(Inactive) awaiting next search
state is entered. If
DONOTENTEROFF
is enabled and no fix is possible, the receiver will remain in
Acquisition
state until a fix is possible
and it will never enter
(Inactive) awaiting next search
state.
3.11.2.1.4 User-controlled operation - update and search period of zero
Setting the CFG-PM-POSUPDATEPERIOD to zero causes the receiver to wait in the
(Inactive)
awaiting next fix
state until woken up by the user. Setting the search period to zero causes the
receiver to wait in the
(Inactive) awaiting next search
state indefinitely after an unsuccessful start-
up. Any wake-up event will re-start the receiver. See section
for more information on wake-
up events.
External wake-up is required when setting update or search period to zero.
3.11.2.1.5 Satellite data download
The receiver is not able to download satellite data (e.g. the ephemeris) while it is working in on/off
or cyclic tracking operation. Therefore it has to temporarily switch to continuous operation for the
time the satellites transmit the desired data. To save power the receiver schedules the downloads
according to an internal timetable and only switches to continuous operation while data of interest
is being transmitted by the satellites.
Each satellite transmits its own ephemeris data. Ephemeris data download is feasible when the
corresponding satellite has been tracked with a sufficient C/N0 over a certain period of time. The
download is scheduled in a 30-minute grid or immediately when fewer than a certain number of
visible satellites have valid ephemeris data.
Almanac, ionosphere, UTC correction and SV health data are transmitted by all SVs simultaneously.
Therefore these parameters can be downloaded when a single SV is tracked with a high enough C/
N0.
Allowing more ephemerides to be downloaded before going into
POT
or
(Inactive) awaiting next
fix
state can help improve the quality of the fixes and reduce the number of wake ups needed
to download ephemerides at the cost of extra time in
Acquisition
state (only when an inadequate
number of ephemerides are downloaded from tracked satellites).
3.11.2.2 Configuration
Power save mode is enabled and disabled with CFG-PM-OPERATEMODE and configured with items
in the CFG-PM group.
When enabling power save mode, the receiver will be unable to download or process any
SBAS data. Therefore, there is no benefit in enabling SBAS and it is recommended to disable
it. SBAS support can be disabled in the CFG-SIGNAL group.
A number of parameters can be used to customize PSM to your specific needs. These parameters,
which can be found in the CFG-PM group, are listed in the following table:
UBX-19014286 - R07
3 Receiver functionality
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