NEO-M9N-Integration manual
3.11.2.2.5 On time (ONTIME)
The ONTIME parameter specifies how long the receiver stays in Tracking state before switching to
the POT state (in PSMCT) or (Inactive) awaiting next fix state (in PSMOO).
3.11.2.2.6 Wait for time fix (WAITTIMEFIX)
A time fix is a fix type in which the receiver will ensure that the time is accurate and confirmed to
within the limits set in CFG-NAVSPG. Enabling the WAITTIMEFIX option will force the receiver to stay
in Acquisition state until the time is known to be within the configured limits, then it will transition to
Tracking state. Take into account that enabling waitTimeFix will delay the transition from Acquisition
state to Tracking state by at least two extra seconds (see Acquisition Timeout). It is necessary to
enable WAITTIMEFIX in timing products.
The quality of the position fixes can also be configured by setting the limits in the CFG-NAVSPG
group. Setting harder limits in CFG-NAVSPG will typically prolong the time in Acquisition state. Thus,
ensuring sufficient time is given to the receiver at start-up (when externally controlled) is necessary
(see Acquisition Timeout Logic). When internally controlled, the receiver can make good judgment
on the time needed in Acquisition state and no further adjustments will be needed.
3.11.2.2.7 Maximum startup state duration (MAXACQTIME)
The MAXACQTIME is the maximum time that the receiver will spend in Startup state (i.e., Acquisition
state). If the receiver is unable to acquire a valid position fix within this maximum time, it will
transition to (Inactive) awaiting next search state (if DONOTENTEROFF is disabled). Subsequently,
the receiver will attempt to acquire another position fix according to the search period (see Update
period (POSUPDATEPERIOD) and search period (ACQPERIOD)). If MAXACQTIME is set to zero,
the receiver will autonomously determine the maximum time to spend in Acquisition state. Note
that shorter settings (below about 45 s) will degrade an unaided receiver's ability to collect new
Ephemeris data at low signal levels (see section Satellite data download).
3.11.2.2.8 Do not enter '(Inactive) awaiting next search' state when no fix (DONOTENTEROFF)
If this option is enabled, the receiver acts differently in case it cannot get a fix: instead of entering
(Inactive) awaiting next search state, it keeps attempting to acquire a position fix. In other words,
the receiver will never be in (Inactive) awaiting next search state and therefore searchPeriod and
MINACQTIME will be ignored.
3.11.2.2.9 Update ephemeris (UPDATEEPH)
To maintain the ability of a fast start-up, the receiver needs to update its ephemeris data on a
regular basis. This can be ensured by activating the update Ephemeris option (UPDATEEPH). The
ephemeris data is updated approximately every 30 minutes. See section Satellite data download for
more information.
3.11.2.2.10 EXTINT pin control
The operation of PSM can be externally controlled using either EXTINT0 or EXTINT1 pin. This
external control allows the user to decide when to wake up the receiver to obtain a fix and when to
force the receiver into sleep/backup mode to save power. Operating the receiver externally through
the EXTINT pins will override internal functions that coincide with that specific operation.
The choice of which pin to use can be configured through the EXTINTSEL feature in CFG-PM. Only
one pin can be selected at a time but it is sufficient to perform all the required tasks.
If the Force-ON (EXTINTWAKE) feature in CFG-PM is enabled, the receiver will not enter Inactive
states for as long as the configured EXTINT pin (EXTINT0 or EXTINT1) is at 'high' level. The receiver
will therefore always be in Acquisition/Tracking state in PSMOO or in Acquisition/Tracking/POT state
in PSMCT. When the pin level changes to 'low' the receiver will continue with its configured behavior.
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