dronecode_sdk::Telemetry Class Reference

#include: telemetry.h

This class allows users to get vehicle telemetry and state information (e.g. battery, GPS, RC connection, flight mode etc.) and set telemetry update rates.

Data Structures

struct Battery

struct EulerAngle

struct GPSInfo

struct GroundSpeedNED

struct Health

struct Position

struct PositionNED

struct PositionVelocityNED

struct Quaternion

struct RCStatus

struct VelocityNED

Public Types

Type	Description
enum FlightMode	Flight modes.
enum Result	Results enum for telemetry requests.
std::function< void(Result)> result_callback_t	Callback type for telemetry requests.
std::function< void(PositionVelocityNED)> position_velocity_ned_callback_t	Callback type for kinematic (position and velocity) updates.
std::function< void(Position)> position_callback_t	Callback type for position updates.
std::function< void(bool in_air)> in_air_callback_t	Callback type for in-air updates.
std::function< void(bool armed)> armed_callback_t	Callback type for armed updates (asynchronous).
std::function< void(Quaternion quaternion)> attitude_quaternion_callback_t	Callback type for attitude updates in quaternion.
std::function< void(EulerAngle euler_angle)> attitude_euler_angle_callback_t	Callback type for attitude updates in Euler angles.
std::function< void(GroundSpeedNED ground_speed_ned)> ground_speed_ned_callback_t	Callback type for ground speed (NED) updates.
std::function< void(GPSInfo gps_info)> gps_info_callback_t	Callback type for GPS information updates.
std::function< void(Battery battery)> battery_callback_t	Callback type for battery status updates.
std::function< void(FlightMode flight_mode)> flight_mode_callback_t	Callback type for flight mode updates.
std::function< void(Health health)> health_callback_t	Callback type for health status updates.
std::function< void(bool health_all_ok)> health_all_ok_callback_t	Callback type for health status updates.
std::function< void(RCStatus rc_status)> rc_status_callback_t	Callback type for RC status updates.

Public Member Functions

Type	Name	Description
	Telemetry (System & system)	Constructor. Creates the plugin for a specific System.
	~Telemetry ()	Destructor (internal use only).
	Telemetry (const Telemetry &)=delete	Copy constructor (object is not copyable).
Result	set_rate_position_velocity_ned (double rate_hz)	Set rate of kinematic (position and velocity) updates (synchronous).
Result	set_rate_position (double rate_hz)	Set rate of position updates (synchronous).
Result	set_rate_home_position (double rate_hz)	Set rate of home position updates (synchronous).
Result	set_rate_in_air (double rate_hz)	Set rate of in-air status updates (synchronous).
Result	set_rate_attitude (double rate_hz)	Set rate of attitude updates (synchronous).
Result	set_rate_camera_attitude (double rate_hz)	Set rate of camera attitude updates (synchronous).
Result	set_rate_ground_speed_ned (double rate_hz)	Set rate of ground speed (NED) updates (synchronous).
Result	set_rate_gps_info (double rate_hz)	Set rate of GPS information updates (synchronous).
Result	set_rate_battery (double rate_hz)	Set rate of battery status updates (synchronous).
Result	set_rate_rc_status (double rate_hz)	Set rate of RC status updates (synchronous).
void	set_rate_position_velocity_ned_async (double rate_hz, result_callback_t callback)	Set rate of kinematic (position and velocity) updates (asynchronous).
void	set_rate_position_async (double rate_hz, result_callback_t callback)	Set rate of position updates (asynchronous).
void	set_rate_home_position_async (double rate_hz, result_callback_t callback)	Set rate of home position updates (asynchronous).
void	set_rate_in_air_async (double rate_hz, result_callback_t callback)	Set rate of in-air status updates (asynchronous).
void	set_rate_attitude_async (double rate_hz, result_callback_t callback)	Set rate of attitude updates (asynchronous).
void	set_rate_camera_attitude_async (double rate_hz, result_callback_t callback)	Set rate of camera attitude updates (asynchronous).
void	set_rate_ground_speed_ned_async (double rate_hz, result_callback_t callback)	Set rate of ground speed (NED) updates (asynchronous).
void	set_rate_gps_info_async (double rate_hz, result_callback_t callback)	Set rate of GPS information updates (asynchronous).
void	set_rate_battery_async (double rate_hz, result_callback_t callback)	Set rate of battery status updates (asynchronous).
void	set_rate_rc_status_async (double rate_hz, result_callback_t callback)	Set rate of RC status updates (asynchronous).
PositionVelocityNED	position_velocity_ned () const	Get the current kinematic (position and velocity) in NED frame (synchronous).
Position	position () const	Get the current position (synchronous).
Position	home_position () const	Get the home position (synchronous).
bool	in_air () const	Get the in-air status (synchronous).
bool	armed () const	Get the arming status (synchronous).
Quaternion	attitude_quaternion () const	Get the current attitude in quaternions (synchronous).
EulerAngle	attitude_euler_angle () const	Get the current attitude in Euler angles (synchronous).
Quaternion	camera_attitude_quaternion () const	Get the camera's attitude in quaternions (synchronous).
EulerAngle	camera_attitude_euler_angle () const	Get the camera's attitude in Euler angles (synchronous).
GroundSpeedNED	ground_speed_ned () const	Get the current ground speed (NED) (synchronous).
GPSInfo	gps_info () const	Get the current GPS information (synchronous).
Battery	battery () const	Get the current battery status (synchronous).
FlightMode	flight_mode () const	Get the current flight mode (synchronous).
Health	health () const	Get the current health status (synchronous).
bool	health_all_ok () const	Returns true if the overall health is ok (synchronous).
RCStatus	rc_status () const	Get the RC status (synchronous).
void	position_velocity_ned_async (position_velocity_ned_callback_t callback)	Subscribe to kinematic (position and velocity) updates (asynchronous).
void	position_async (position_callback_t callback)	Subscribe to position updates (asynchronous).
void	home_position_async (position_callback_t callback)	Subscribe to home position updates (asynchronous).
void	in_air_async (in_air_callback_t callback)	Subscribe to in-air updates (asynchronous).
void	armed_async (armed_callback_t callback)	Subscribe to armed updates (asynchronous).
void	attitude_quaternion_async (attitude_quaternion_callback_t callback)	Subscribe to attitude updates in quaternion (asynchronous).
void	attitude_euler_angle_async (attitude_euler_angle_callback_t callback)	Subscribe to attitude updates in Euler angles (asynchronous).
void	camera_attitude_quaternion_async (attitude_quaternion_callback_t callback)	Subscribe to camera attitude updates in quaternion (asynchronous).
void	camera_attitude_euler_angle_async (attitude_euler_angle_callback_t callback)	Subscribe to camera attitude updates in Euler angles (asynchronous).
void	ground_speed_ned_async (ground_speed_ned_callback_t callback)	Subscribe to ground speed (NED) updates (asynchronous).
void	gps_info_async (gps_info_callback_t callback)	Subscribe to GPS information updates (asynchronous).
void	battery_async (battery_callback_t callback)	Subscribe to battery status updates (asynchronous).
void	flight_mode_async (flight_mode_callback_t callback)	Subscribe to flight mode updates (asynchronous).
void	health_async (health_callback_t callback)	Subscribe to health status updates (asynchronous).
void	health_all_ok_async (health_all_ok_callback_t callback)	Subscribe to overall health status updates (asynchronous).
void	rc_status_async (rc_status_callback_t callback)	Subscribe to RC status updates (asynchronous).
const Telemetry &	operator= (const Telemetry &)=delete	Equality operator (object is not copyable).

Static Public Member Functions

Type	Name	Description
std::string	flight_mode_str (FlightMode flight_mode)	Get a human readable English string for a flight mode.
const char *	result_str (Result result)	Get human-readable English string for Telemetry::Result.

Constructor & Destructor Documentation

Telemetry()

dronecode_sdk::Telemetry::Telemetry(System &system)

Constructor. Creates the plugin for a specific System.

The plugin is typically created as shown below:

auto telemetry = std::make_shared<Telemetry>(system);

Parameters

System& system - The specific system associated with this plugin.

~Telemetry()

dronecode_sdk::Telemetry::~Telemetry()

Destructor (internal use only).

Telemetry()

dronecode_sdk::Telemetry::Telemetry(const Telemetry &)=delete

Copy constructor (object is not copyable).

Parameters

const Telemetry& -

Member Typdef Documentation

typedef result_callback_t

typedef std::function<void(Result)> dronecode_sdk::Telemetry::result_callback_t

Callback type for telemetry requests.

typedef position_velocity_ned_callback_t

typedef std::function<void(PositionVelocityNED)> dronecode_sdk::Telemetry::position_velocity_ned_callback_t

Callback type for kinematic (position and velocity) updates.

typedef position_callback_t

typedef std::function<void(Position)> dronecode_sdk::Telemetry::position_callback_t

Callback type for position updates.

typedef in_air_callback_t

typedef std::function<void(bool in_air)> dronecode_sdk::Telemetry::in_air_callback_t

Callback type for in-air updates.

Parameters

in_air - true if in-air (flying) and not on-ground (landed).

typedef armed_callback_t

typedef std::function<void(bool armed)> dronecode_sdk::Telemetry::armed_callback_t

Callback type for armed updates (asynchronous).

Parameters

armed - true if armed (motors spinning).

typedef attitude_quaternion_callback_t

typedef std::function<void(Quaternion quaternion)> dronecode_sdk::Telemetry::attitude_quaternion_callback_t

Callback type for attitude updates in quaternion.

Parameters

quaternion - Attitude quaternion.

typedef attitude_euler_angle_callback_t

typedef std::function<void(EulerAngle euler_angle)> dronecode_sdk::Telemetry::attitude_euler_angle_callback_t

Callback type for attitude updates in Euler angles.

Parameters

euler_angle - Attitude Euler angle.

typedef ground_speed_ned_callback_t

typedef std::function<void(GroundSpeedNED ground_speed_ned)> dronecode_sdk::Telemetry::ground_speed_ned_callback_t

Callback type for ground speed (NED) updates.

Parameters

ground_speed_ned - Ground speed (NED).

typedef gps_info_callback_t

typedef std::function<void(GPSInfo gps_info)> dronecode_sdk::Telemetry::gps_info_callback_t

Callback type for GPS information updates.

Parameters

gps_info - GPS information.

typedef battery_callback_t

typedef std::function<void(Battery battery)> dronecode_sdk::Telemetry::battery_callback_t

Callback type for battery status updates.

Parameters

battery - Battery status.

typedef flight_mode_callback_t

typedef std::function<void(FlightMode flight_mode)> dronecode_sdk::Telemetry::flight_mode_callback_t

Callback type for flight mode updates.

Parameters

flight_mode - Flight mode.

typedef health_callback_t

typedef std::function<void(Health health)> dronecode_sdk::Telemetry::health_callback_t

Callback type for health status updates.

Parameters

health - health flags.

typedef health_all_ok_callback_t

typedef std::function<void(bool health_all_ok)> dronecode_sdk::Telemetry::health_all_ok_callback_t

Callback type for health status updates.

Parameters

health_all_ok - If all health flags are ok.

typedef rc_status_callback_t

typedef std::function<void(RCStatus rc_status)> dronecode_sdk::Telemetry::rc_status_callback_t

Callback type for RC status updates.

Parameters

rc_status - RC status.

Member Enumeration Documentation

enum FlightMode

Flight modes.

For more information about flight modes, check out https://docs.px4.io/en/config/flight_mode.html.

Value	Description
`READY`	Armed and ready to take off.
`TAKEOFF`	Taking off.
`HOLD`	Hold mode (hovering in place (or circling for fixed-wing vehicles).
`MISSION`	Mission mode.
`RETURN_TO_LAUNCH`	Returning to launch position (then landing).
`LAND`	Landing.
`OFFBOARD`	Offboard mode.
`FOLLOW_ME`	FollowMe mode.
`UNKNOWN`	Mode not known.

enum Result

Results enum for telemetry requests.

Value	Description
`SUCCESS`	Request succeeded.
`NO_SYSTEM`	No system connected.
`CONNECTION_ERROR`	Connection error.
`BUSY`	System busy.
`COMMAND_DENIED`	Command denied.
`TIMEOUT`	Request timeout.
`UNKNOWN`	Unknown error.

Member Function Documentation

set_rate_position_velocity_ned()

Result dronecode_sdk::Telemetry::set_rate_position_velocity_ned(double rate_hz)

Set rate of kinematic (position and velocity) updates (synchronous).

Parameters

double rate_hz - Rate in Hz.

Returns

Result - Result of request.

See Also:

PositionVelocityNED

set_rate_position()

Result dronecode_sdk::Telemetry::set_rate_position(double rate_hz)

Set rate of position updates (synchronous).

Parameters

double rate_hz - Rate in Hz.

Returns

Result - Result of request.

set_rate_home_position()

Result dronecode_sdk::Telemetry::set_rate_home_position(double rate_hz)

Set rate of home position updates (synchronous).

Parameters

double rate_hz - Rate in Hz.

Returns

Result - Result of request.

set_rate_in_air()

Result dronecode_sdk::Telemetry::set_rate_in_air(double rate_hz)

Set rate of in-air status updates (synchronous).

Parameters

double rate_hz - Rate in Hz.

Returns

Result - Result of request.

set_rate_attitude()

Result dronecode_sdk::Telemetry::set_rate_attitude(double rate_hz)

Set rate of attitude updates (synchronous).

Parameters

double rate_hz - Rate in Hz.

Returns

Result - Result of request.

set_rate_camera_attitude()

Result dronecode_sdk::Telemetry::set_rate_camera_attitude(double rate_hz)

Set rate of camera attitude updates (synchronous).

Parameters

double rate_hz - Rate in Hz.

Returns

Result - Result of request.

set_rate_ground_speed_ned()

Result dronecode_sdk::Telemetry::set_rate_ground_speed_ned(double rate_hz)

Set rate of ground speed (NED) updates (synchronous).

Parameters

double rate_hz - Rate in Hz.

Returns

Result - Result of request.

set_rate_gps_info()

Result dronecode_sdk::Telemetry::set_rate_gps_info(double rate_hz)

Set rate of GPS information updates (synchronous).

Parameters

double rate_hz - Rate in Hz.

Returns

Result - Result of request.

set_rate_battery()

Result dronecode_sdk::Telemetry::set_rate_battery(double rate_hz)

Set rate of battery status updates (synchronous).

Parameters

double rate_hz - Rate in Hz.

Returns

Result - Result of request.

set_rate_rc_status()

Result dronecode_sdk::Telemetry::set_rate_rc_status(double rate_hz)

Set rate of RC status updates (synchronous).

Parameters

double rate_hz - Rate in Hz.

Returns

Result - Result of request.

set_rate_position_velocity_ned_async()

void dronecode_sdk::Telemetry::set_rate_position_velocity_ned_async(double rate_hz, result_callback_t callback)

Set rate of kinematic (position and velocity) updates (asynchronous).

Parameters

double rate_hz - Rate in Hz.
result_callback_t callback - Callback to receive request result.

See Also:

PositionVelocityNED

set_rate_position_async()

void dronecode_sdk::Telemetry::set_rate_position_async(double rate_hz, result_callback_t callback)

Set rate of position updates (asynchronous).

Parameters

double rate_hz - Rate in Hz.
result_callback_t callback - Callback to receive request result.

set_rate_home_position_async()

void dronecode_sdk::Telemetry::set_rate_home_position_async(double rate_hz, result_callback_t callback)

Set rate of home position updates (asynchronous).

Parameters

double rate_hz - Rate in Hz.
result_callback_t callback - Callback to receive request result.

set_rate_in_air_async()

void dronecode_sdk::Telemetry::set_rate_in_air_async(double rate_hz, result_callback_t callback)

Set rate of in-air status updates (asynchronous).

Parameters

double rate_hz - Rate in Hz.
result_callback_t callback - Callback to receive request result.

set_rate_attitude_async()

void dronecode_sdk::Telemetry::set_rate_attitude_async(double rate_hz, result_callback_t callback)

Set rate of attitude updates (asynchronous).

Parameters

double rate_hz - Rate in Hz.
result_callback_t callback - Callback to receive request result.

set_rate_camera_attitude_async()

void dronecode_sdk::Telemetry::set_rate_camera_attitude_async(double rate_hz, result_callback_t callback)

Set rate of camera attitude updates (asynchronous).

Parameters

double rate_hz - Rate in Hz.
result_callback_t callback - Callback to receive request result.

set_rate_ground_speed_ned_async()

void dronecode_sdk::Telemetry::set_rate_ground_speed_ned_async(double rate_hz, result_callback_t callback)

Set rate of ground speed (NED) updates (asynchronous).

Parameters

double rate_hz - Rate in Hz.
result_callback_t callback - Callback to receive request result.

set_rate_gps_info_async()

void dronecode_sdk::Telemetry::set_rate_gps_info_async(double rate_hz, result_callback_t callback)

Set rate of GPS information updates (asynchronous).

Parameters

double rate_hz - Rate in Hz.
result_callback_t callback - Callback to receive request result.

set_rate_battery_async()

void dronecode_sdk::Telemetry::set_rate_battery_async(double rate_hz, result_callback_t callback)

Set rate of battery status updates (asynchronous).

Parameters

double rate_hz - Rate in Hz.
result_callback_t callback - Callback to receive request result.

set_rate_rc_status_async()

void dronecode_sdk::Telemetry::set_rate_rc_status_async(double rate_hz, result_callback_t callback)

Set rate of RC status updates (asynchronous).

Parameters

double rate_hz - Rate in Hz.
result_callback_t callback - Callback to receive request result.

position_velocity_ned()

PositionVelocityNED dronecode_sdk::Telemetry::position_velocity_ned() const

Get the current kinematic (position and velocity) in NED frame (synchronous).

Returns

PositionVelocityNED - PositionVelocityNED.

position()

Position dronecode_sdk::Telemetry::position() const

Get the current position (synchronous).

Returns

Position - Position.

home_position()

Position dronecode_sdk::Telemetry::home_position() const

Get the home position (synchronous).

Returns

Position - Home position.

in_air()

bool dronecode_sdk::Telemetry::in_air() const

Get the in-air status (synchronous).

Returns

bool - true if in-air (flying) and not on-ground (landed).

armed()

bool dronecode_sdk::Telemetry::armed() const

Get the arming status (synchronous).

Returns

bool - true if armed (propellers spinning).

attitude_quaternion()

Quaternion dronecode_sdk::Telemetry::attitude_quaternion() const

Get the current attitude in quaternions (synchronous).

Returns

Quaternion - Attitude as quaternion.

attitude_euler_angle()

EulerAngle dronecode_sdk::Telemetry::attitude_euler_angle() const

Get the current attitude in Euler angles (synchronous).

Returns

EulerAngle - Attitude as Euler angle.

camera_attitude_quaternion()

Quaternion dronecode_sdk::Telemetry::camera_attitude_quaternion() const

Get the camera's attitude in quaternions (synchronous).

Note that the yaw component of attitude is relative to North (absolute frame).

Returns

Quaternion - Camera's attitude as quaternion.

camera_attitude_euler_angle()

EulerAngle dronecode_sdk::Telemetry::camera_attitude_euler_angle() const

Get the camera's attitude in Euler angles (synchronous).

Note that the yaw component of attitude is relative to North (absolute frame).

Returns

EulerAngle - Camera's attitude as Euler angle.

ground_speed_ned()

GroundSpeedNED dronecode_sdk::Telemetry::ground_speed_ned() const

Get the current ground speed (NED) (synchronous).

Returns

GroundSpeedNED - Ground speed in NED.

gps_info()

GPSInfo dronecode_sdk::Telemetry::gps_info() const

Get the current GPS information (synchronous).

Returns

GPSInfo - GPS information.

battery()

Battery dronecode_sdk::Telemetry::battery() const

Get the current battery status (synchronous).

Returns

Battery -

flight_mode()

FlightMode dronecode_sdk::Telemetry::flight_mode() const

Get the current flight mode (synchronous).

Returns

FlightMode - Flight mode.

health()

Health dronecode_sdk::Telemetry::health() const

Get the current health status (synchronous).

Returns

Health - Health status.

health_all_ok()

bool dronecode_sdk::Telemetry::health_all_ok() const

Returns true if the overall health is ok (synchronous).

Returns

bool - True if all health flags are OK.

rc_status()

RCStatus dronecode_sdk::Telemetry::rc_status() const

Get the RC status (synchronous).

Returns

RCStatus - RC status.

position_velocity_ned_async()

void dronecode_sdk::Telemetry::position_velocity_ned_async(position_velocity_ned_callback_t callback)

Subscribe to kinematic (position and velocity) updates (asynchronous).

Parameters

position_velocity_ned_callback_t callback - Function to call with updates.

position_async()

void dronecode_sdk::Telemetry::position_async(position_callback_t callback)

Subscribe to position updates (asynchronous).

Parameters

position_callback_t callback - Function to call with updates.

home_position_async()

void dronecode_sdk::Telemetry::home_position_async(position_callback_t callback)

Subscribe to home position updates (asynchronous).

Parameters

position_callback_t callback - Function to call with updates.

in_air_async()

void dronecode_sdk::Telemetry::in_air_async(in_air_callback_t callback)

Subscribe to in-air updates (asynchronous).

Parameters

in_air_callback_t callback - Function to call with updates.

armed_async()

void dronecode_sdk::Telemetry::armed_async(armed_callback_t callback)

Subscribe to armed updates (asynchronous).

Note that armed updates are limited to 1Hz.

Parameters

armed_callback_t callback - Function to call with updates.

attitude_quaternion_async()

void dronecode_sdk::Telemetry::attitude_quaternion_async(attitude_quaternion_callback_t callback)

Subscribe to attitude updates in quaternion (asynchronous).

Parameters

attitude_quaternion_callback_t callback - Function to call with updates.

attitude_euler_angle_async()

void dronecode_sdk::Telemetry::attitude_euler_angle_async(attitude_euler_angle_callback_t callback)

Subscribe to attitude updates in Euler angles (asynchronous).

Parameters

attitude_euler_angle_callback_t callback - Function to call with updates.

camera_attitude_quaternion_async()

void dronecode_sdk::Telemetry::camera_attitude_quaternion_async(attitude_quaternion_callback_t callback)

Subscribe to camera attitude updates in quaternion (asynchronous).

Parameters

attitude_quaternion_callback_t callback - Function to call with updates.

camera_attitude_euler_angle_async()

void dronecode_sdk::Telemetry::camera_attitude_euler_angle_async(attitude_euler_angle_callback_t callback)

Subscribe to camera attitude updates in Euler angles (asynchronous).

Parameters

attitude_euler_angle_callback_t callback - Function to call with updates.

ground_speed_ned_async()

void dronecode_sdk::Telemetry::ground_speed_ned_async(ground_speed_ned_callback_t callback)

Subscribe to ground speed (NED) updates (asynchronous).

Parameters

ground_speed_ned_callback_t callback - Function to call with updates.

gps_info_async()

void dronecode_sdk::Telemetry::gps_info_async(gps_info_callback_t callback)

Subscribe to GPS information updates (asynchronous).

Parameters

gps_info_callback_t callback - Function to call with updates.

battery_async()

void dronecode_sdk::Telemetry::battery_async(battery_callback_t callback)

Subscribe to battery status updates (asynchronous).

Parameters

battery_callback_t callback - Function to call with updates.

flight_mode_async()

void dronecode_sdk::Telemetry::flight_mode_async(flight_mode_callback_t callback)

Subscribe to flight mode updates (asynchronous).

Note that flight mode updates are limited to 1Hz.

Parameters

flight_mode_callback_t callback - Function to call with updates.

health_async()

void dronecode_sdk::Telemetry::health_async(health_callback_t callback)

Subscribe to health status updates (asynchronous).

Note that health status updates are limited to 1Hz.

Parameters

health_callback_t callback - Function to call with updates.

health_all_ok_async()

void dronecode_sdk::Telemetry::health_all_ok_async(health_all_ok_callback_t callback)

Subscribe to overall health status updates (asynchronous).

Note that overall health status updates are limited to 1Hz.

Parameters

health_all_ok_callback_t callback - Function to call with updates.

rc_status_async()

void dronecode_sdk::Telemetry::rc_status_async(rc_status_callback_t callback)

Subscribe to RC status updates (asynchronous).

Parameters

rc_status_callback_t callback - Function to call with updates.

operator=()

const Telemetry& dronecode_sdk::Telemetry::operator=(const Telemetry &)=delete

Equality operator (object is not copyable).

Parameters

const Telemetry& -

Returns

const Telemetry & -

flight_mode_str()

static std::string dronecode_sdk::Telemetry::flight_mode_str(FlightMode flight_mode)

Get a human readable English string for a flight mode.

Parameters

FlightMode flight_mode -

Returns

std::string -

result_str()

static const char* dronecode_sdk::Telemetry::result_str(Result result)

Get human-readable English string for Telemetry::Result.

Parameters

Result result - The enum value for which string is needed.

Returns

const char * - Human readable string for the Telemetry::Result.