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
). 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
). 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
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
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
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.
UBX-19014286 - R07
3 Receiver functionality
Page 48 of 95
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