Detailed Description

The time of applicability and additional information for an incoming sensor measurement.

By convention this will be the first member of any message containing input measurements by the host to the device, as well as raw measurement outputs from the device.

The measurement_time field stores time of applicability/reception for the measurement data, expressed in one of the available source time bases (see SystemTimeSource). The timestamp will be converted to P1 time automatically by FusionEngine using an internal model of P1 vs. the specified source time.

Timestamp On Arrival

On most platforms, incoming sensor measurements are timestamped automatically by FusionEngine when they arrive. To request timestamp on arrival, set measurement_time_source to either SystemTimeSource::TIMESTAMPED_ON_RECEPTION or SystemTimeSource::INVALID.

Timestamp Externally

On some platforms, incoming sensor measurements may be timestamped externally by the host prior to arrival, either in GPS time (SystemTimeSource::GPS_TIME), or using a monotonic clock controlled by the host system (SystemTimeSource::SENDER_SYSTEM_TIME). For those platforms, the measurement_time field should be specified in the incoming message.

Note: Use of an external monotonic clock requires additional coordination with the target FusionEngine device.

Timestamp With External P1 Time

Measurements may only be timestamped externally using P1 time (SystemTimeSource::P1_TIME) if the external system supports remote synchronization of the P1 time clock model. This is intended for internal use only.

Definition at line 193 of file measurements.h.

#include <point_one/fusion_engine/messages/measurements.h>

Public Attributes
SensorDataSource	data_source = SensorDataSource::UNKNOWN
	The source of the incoming data, if known. More...

Timestamp	measurement_time
	The measurement time of applicability, if available, in a user-specified time base. More...

SystemTimeSource	measurement_time_source = SystemTimeSource::INVALID
	The source for measurement_time. More...

Timestamp	p1_time
	The P1 time corresponding with the measurement time of applicability, if available. More...

Member Data Documentation

◆ data_source

SensorDataSource point_one::fusion_engine::messages::MeasurementDetails::data_source = SensorDataSource::UNKNOWN

The source of the incoming data, if known.

Definition at line 210 of file measurements.h.

◆ measurement_time

Timestamp point_one::fusion_engine::messages::MeasurementDetails::measurement_time

The measurement time of applicability, if available, in a user-specified time base.

The source of this value is specified in measurement_time_source. The timestamp will be converted to P1 time internally by the device before use.

Definition at line 200 of file measurements.h.

◆ measurement_time_source

SystemTimeSource point_one::fusion_engine::messages::MeasurementDetails::measurement_time_source = SystemTimeSource::INVALID

The source for measurement_time.

Definition at line 205 of file measurements.h.

◆ p1_time

Timestamp point_one::fusion_engine::messages::MeasurementDetails::p1_time

The P1 time corresponding with the measurement time of applicability, if available.

For inputs to the device, this field will be populated automatically by the device on arrival based on measurement_time. Any existing value will be overwritten. To specify a known P1 time, specify the value in measurement_time and set measurement_time_source to SystemTimeSource::P1_TIME.

For outputs from the device, this field will always be populated with the P1 time corresponding with the measurement.

Definition at line 227 of file measurements.h.

The documentation for this struct was generated from the following file:

src/point_one/fusion_engine/messages/measurements.h