SAM-M10Q - Integration manual
• If the receiver is able to acquire weak signals but not of the quality needed to get a fix, it will
transition to the "Inactive for search" state after the timeout configured in MAXACQTIME or
earlier if too few signals are acquired.
• If the receiver is unable to acquire any signals or it acquires a small number of extremely bad
signals (e.g., no sky view), it will transition to the "Inactive for search" state after the timeout
configured in MAXACQTIME.
User-configurable mechanisms:
• MINACQTIME is the minimum time that the receiver will spend in the "Acquisition" state
• MAXACQTIME is the maximum time that the receiver will spend in the "Acquisition" state.
• DONOTENTEROFF forces the receiver to stay awake and in the "Acquisition" state even when a
fix is not possible.
External mechanisms:
• The receiver is forced to stay awake if EXTINTWAKE is enabled and the EXTINT pin is set to
"high". The receiver is forced to stay in the "Inactive for search/Fix" states if EXTINTBACKUP is
enabled and the EXTINT pin is set to "low".
• The receiver is forced to stay awake if EXTINTINACTIVE is enabled and the EXTINT pin is
toggled. If EXTINT pin state is not changed for a longer time than EXTINTINACTIVITY, the
receiver enters the "Inactive for search/Fix" states.
2.6.2.3 Cyclic tracking
Power save mode cyclic tracking (PSMCT) operation is described in
.
PSMCT supports 1 Hz and 2 Hz navigation update rates. In addition, longer update periods
from 2 s to 10 s are supported at 1 s steps.
Figure 11: Cyclic tracking operation
• When the receiver is switched on, it first enters the "Acquisition" state. A non-zero value for
MINACQTIME increases the acquisition period and allows the receiver to acquire more satellites
at startup. A larger number of signals tracked later helps the receiver to remain in the "POT"
state if some signals get blocked and are lost. This may reduce the overall power consumption.
• If it is able to acquire a valid position fix (one passing the navigation output filters) within the
time given by the
, it switches to the "Tracking" state and the ONTIME
starts. Otherwise it enters the "Inactive for search" state and restarts after the configured
search period (minus a start-up margin).
• Once the ONTIME is over, the "POT" state is entered. Setting the ONTIME to zero causes the
receiver to enter the "POT" state as soon as possible.
• In the "POT" state the receiver continues to output position fixes according to the CFG-RATE-*.
• If the signal becomes weak or is lost during the "POT" state, the "Tracking" state is entered.
• Once the signal is good again and the newly started ONTIME is over, the receiver will re-enter
the "POT" state.
UBX-22020019 - R01
2 Receiver functionality
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