ZED-F9K - Integration manual
The monitoring algorithm relies on comparing the currently measured spectrum with a
reference from when a good fix was obtained. Thus the monitor will only function when the
receiver has had at least one (good) first fix, and will report "Unknown" before this time.
The monitor is reporting any currently detected interference over all currently configured signal
bands.
3.10.3 GNSS receiver integrity
3.10.3.1 Secure boot
The ZED-F9K boots only with firmware images that are signed by u-blox. This prevents the execution
of non-genuine firmware images run on the receiver.
3.10.3.2 Secure firmware update
The firmware image itself is encrypted and signed by u-blox. The ZED-F9K verifies the signature at
each start.
3.10.3.3 Receiver configuration lockdown
The receiver configuration lockdown feature ensures that no configuration changes are possible
once the feature is enabled. The configuration lockdown is enabled by setting the configuration item
CFG-SEC-CFG_LOCK to "true".
The configuration lockdown can be applied to different configuration layers including the RAM,
BBR, and flash memory. At startup, the receiver constructs the configuration database from
different configuration layers and maintains it in the run-time RAM memory. When the configuration
lockdown is set in the run-time RAM, the receiver configuration cannot be changed on any
configuration layer.
For more information on the configuration layers including the order of priority they are
applied in, see the ZED-F9K Interface description [
].
The configuration lockdown set on a configuration layer in volatile memory (RAM, BBR) is removed
when the memory is cleared. However, the configuration lockdown set in non-volatile memory (flash
memory) is permanent apart from one exception: during firmware upload to flash memory, the flash
is erased during the process causing the configuration lockdown to be cleared. Refer to
for more information on firmware update.
To test the lockdown functionality, set it on the RAM configuration layer. After a power cycle, the
information on RAM layer is cleared and the lockdown is no longer set.
It is recommended to apply the configuration lockdown on the same layer the configuration
is stored.
3.11 u-blox protocol feature descriptions
3.11.1 Broadcast navigation data
This section describes the data reported via UBX-RXM-SFRBX.
UBX-RXM-SFRBX reports the broadcast navigation data message the receiver has collected from
each tracked signal. When enabled, a separate message is generated each time the receiver decodes
a complete subframe of data from a tracked signal. The data bits are reported as received, including
preambles and error checking bits as appropriate. However, because there is considerable variation
in the data structure of the different GNSS signals, the form of the reported data also varies. This
UBX-20046189 - R01
3 Receiver functionality
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C1-Public
Early production information
