RCB-F9T - Integration manual
The geofencing feature allows for the configuration of up to four circular areas (geofences) on the
Earth's surface. The receiver will then evaluate for each of these areas whether the current position
lies within the area or not and signal the state via UBX messaging and PIO toggling.
3.2.2 Interface
Geofencing can be configured using the CFG-GEOFENCE-* configuration group. The geofence
evaluation is active whenever there is at least one geofence configured.
The current state of each geofence plus the combined state is output in UBX-NAV-GEOFENCE with
every navigation epoch.
Additionally the user can configure the receiver to output the combined geofence state on a physical
pin (assigned to a PIO being used for geofence state indication).
3.2.3 Geofence state evaluation
With every navigation epoch the receiver will evaluate the current solution's position versus the
configured geofences. There are three possible outcomes for each geofence:
•
Inside
- The position is inside the geofence with the configured confidence level
•
Outside
- The position lies outside of the geofence with the configured confidence level
•
Unknown
- There is no valid position solution or the position uncertainty does not allow for
unambiguous state evaluation
The position solution uncertainty (standard deviation) is multiplied with the configured confidence
sigma level number and taken into account when evaluating the geofence state (red circle in figure
below).
Figure 6: Geofence states
The combined state for all geofences is evaluated as the combination (Union) of all geofences:
•
Inside
- The position lies inside of at least one geofence
•
Outside
- The position lies outside of all geofences
•
Unknown
- All remaining states
3.3 Interfaces
RCB-F9T provides a UART interface for communication with a host CPU.
It is important to isolate interface pins when the RCB-F9T VCC is removed. They can be
allowed to float or connected to a high impedance.
3.3.1 UART interface
RCB-F9T includes one UART port.
UART
can be used for host interface. It supports a configurable baud rate and protocol selection.
The default baud rate is 115200 baud. To prevent buffering problems it is recommended
not to run at a lower baud rate than 38400 baud.
UBX-19003747 - R04
3 Receiver functionality
Page 17 of 54
Early production information
