LENA-R8 series - System integration manual
UBX-22015376 - R02
System description
Page 15 of 116
C1-Public
1.5.3.1
GNSS continuous mode
The UBX-M10050-KB GNSS receiver uses dedicated signal processing engines optimized for signal
acquisition and tracking. The acquisition engine actively searches for and acquires signals during cold
starts or
when insufficient signals are available during navigation. The tracking engine continuously
tracks and downloads all the almanac data and acquires new signals as they become available during
navigation. The tracking engine consumes less power than the acquisition engine.
The current consumption is lower when a valid position is obtained quickly after the start of the
receiver navigation, the entire almanac has been downloaded, and the ephemeris for each satellite in
view is valid. If these conditions are not met, the search for the available satellites takes more time
and consumes more power.
☞
For further details about GNSS continuous mode, see the u-blox UBX-M10050-KB integration
manual
and the u-blox M10 SPG 5.10 interface description
1.5.3.2
GNSS power save mode
Power Save Mode (PSM) allows a reduction in the GNSS system power consumption by selectively
switching
parts of the receiver on and off.
Power Save Mode (PSM) has two modes of operation:
•
Power Save Mode Cyclic Tracking (
PSMCT) operation is used when position fixes are required in
short periods of 0.5 s to 10 s.
•
Power
Save Mode On/Off
(PSMOO) operation is used for periods longer than 10 s, and can be in
the order of minutes, hours, or days.
The mode of operation can be configured, and depending on the setting, the receiver demonstrates
different behavior: In on/off operation the receiver switches between
phases of startup/navigation
and phases with low or almost no system activity (backup/sleep). In cyclic tracking the receiver does
not shut down completely between fixes, but uses low
-power tracking instead.
☞
BeiDou B1C is not supported in power save mode.
GPS, GLONASS, BeiDou B1I, Galileo and QZSS signals are supported in power save mode. BeiDou B1C
signal is not supported. The receiver is unable to download or process any SBAS data in GNSS power
save mode and it is therefore recommended to disable SBAS.
☞
For further details about GNSS power save mode (operation, acquisition, cyclic tracking, on/off
mode, external control, c
onfiguration
, satellite data download), see the u-blox UBX-M10050-KB
integration manual
and the u-blox M10 SPG 5.10 interface description
1.5.3.3
GNSS backup mode
A backup mode is an inactive state where the power consumption is reduced to a fraction of that in
operating modes. The receiver maintains time information and navigation data to speed up the
receiver restart after backup or standby mode.
LENA-R8001M10 GNSS system supports hardware backup mode and software standby mode.
GNSS
hardware backup mode
The hardware backup mode allows entering a backup state and resuming operation by switching the
power supplies on and off. The receiver automatically enters the hardware backup mode if the
VCC_GNSS
is removed. The hardware backup mode always requires an independent backup battery.
VBCKP_GNSS
must be supplied to maintain the backup domain (BBR and RTC) to allow better TTFF,
accuracy, availability, and power consumption at the next startup. As V_IO is not supplied, the PIOs
cannot be driven by an external host processor. If driving of the PIOs cannot be avoided, buffers are
required for isolating the PIOs.