ZED-F9R - Integration manual
Figure 5: Time mark on external input
3.2.4.2.3 UBX-ESF-MEAS time tagging configuration
The time tag factor can be used to convert the sensor time tags into the required seconds.
It is essential that the time tags used for all UBX-ESF-MEAS data have the same resolution.
ZED-F9R automatically generates UBX-ESF-MEAS messages containing measurements from the
internal IMU using the default time tag resolution of 1 millisecond. If the customer wants to input
odometer data with UBX-ESF-MEAS messages, it is essential that the odometer time tag has a
resolution of 1 millisecond.
ZED-F9R automatically generates UBX-ESF-MEAS messages containing measurements from the
internal IMU. If the customer inputs UBX-ESF-MEAS with odometer data with a different sensor
time tag factor than that used by ZED-F9R for IMU data, it will fail!
The same sensor time-tag (ttag) factor must be used for all UBX-ESF-MEAS data.
The following sensor time tagging settings need to be specified:
•
CFG-SFCORE-SEN_TTAG_FACT:
This parameter can be used to convert the sensor time tags
from their original time unit into the required seconds. It has a resolution of 1 micro second. The
default value is 1000 (1 millisecond).
•
CFG-SFCORE-SEN_TTAG_MAX:
External sensor time tags can be encoded in different data
types (signed/unsigned, varying number of bytes) which might vary across sensor types. For
example, if the IMU raw packet's time-tag field is encoded into an unsigned long integer (4
bytes), the maximum possible time-tag value is
4294967295
(
0xFFFFFFFF
in hexadecimal).
3.2.5 HPS system configuration
3.2.5.1 Enabling/disabling fusion filter
The HPS feature can be enabled and disabled with the
CFG-SFCORE-USE_SF
key. If HPS is disabled,
the receiver outputs a GNSS-only solution. IMU sensor measurements are still available in UBX-ESF-
MEAS and UBX-ESF-RAW messages.
3.2.5.2 Recommended configuration
In general, it is recommended to use the default configuration values in order to achieve optimal HPS
navigation performance.
By default, the navigation solution update rate is 1 Hz. It can be configured with the
CFG-RATE-NAV
key.
UBX-20039643 - R01
3 Receiver functionality
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