p_sopc_zephyr_time.h File Reference

#include <stdbool.h>
#include <stdint.h>
#include "sopc_time_reference.h"

Go to the source code of this file.

Enumerations
enum	SOPC_Time_TimeSource { SOPC_TIME_TIMESOURCE_INTERNAL , SOPC_TIME_TIMESOURCE_PTP_SLAVE , SOPC_TIME_TIMESOURCE_PTP_MASTER }
	This file provides time related ZEPHYR-specific implementations which are defined in "sopc_time_reference.h". More...

Functions
SOPC_Time_TimeSource	SOPC_Time_GetTimeSource (void)
	returns the current time source used for time-related operations (including timestamping)
float	SOPC_Time_GetClockPrecision (void)
	returns an evaluation of the system clock precision (relatively to a remote PtP MASTER) This value can be used to check that PtP clock is sufficiently synchronized before allowing some time-related events, typically like sending Publisher messages with PublishOffset constraints. The threshold value may clearly be determined experimentally depending on expected precision.
float	SOPC_Time_GetClockCorrection (void)
	Provides the information about clock discrepancy towards a PtP master.

Enumeration Type Documentation

SOPC_Time_TimeSource

enum SOPC_Time_TimeSource

This file provides time related ZEPHYR-specific implementations which are defined in "sopc_time_reference.h".

Note

The ZEPHYR PtP time correction is realized while processing specific time events (SOPC_Time_GetCurrentTimeUTC). Natively, in S2OPC core, this function may not be called as long as no PubSub is started. As a consequence, in the case an application waits for a PtP synchronization before activating this service, it is mandatory to firstly force this synchronization by calling this functions explicitly until synchronization is good enough. A simple way to do that could be calling SOPC_Time_GetCurrentTimeUTC function as long as SOPC_HighRes_TimeReference_GetClockPrecision does not return sufficient precision.

Possible time sources

Enumerator
SOPC_TIME_TIMESOURCE_INTERNAL	Local system time, non-ptp synchronized
SOPC_TIME_TIMESOURCE_PTP_SLAVE	PtP time (acting as SLAVE device)
SOPC_TIME_TIMESOURCE_PTP_MASTER	PtP time (acting as MASTER device)

Function Documentation

SOPC_Time_GetTimeSource()

SOPC_Time_TimeSource SOPC_Time_GetTimeSource

(

void

)

returns the current time source used for time-related operations (including timestamping)

SOPC_Time_GetClockPrecision()

float SOPC_Time_GetClockPrecision

(

void

)

returns an evaluation of the system clock precision (relatively to a remote PtP MASTER) This value can be used to check that PtP clock is sufficiently synchronized before allowing some time-related events, typically like sending Publisher messages with PublishOffset constraints. The threshold value may clearly be determined experimentally depending on expected precision.

Returns

A value between 0.0 and 1.0:

• 1.0 for a perfectly synchronized PtP SLAVE (typically, current time source is SOPC_TIME_TIMESOURCE_PTP_SLAVE and remote PtP time is perfectly synchronized and stable with S2OPC internal clock)
• 0.0 if there is no PtP synchronization (not PtP SLAVE or SLAVE but with clock failed to stabilize)

SOPC_Time_GetClockCorrection()

float SOPC_Time_GetClockCorrection

(

void

)

Provides the information about clock discrepancy towards a PtP master.

Returns

clock ratio discrepancy: < 1.0 when local clock is faster than actual (PtP) time

‍1.0 when local clock is slower than actual (PtP) time