Table 1. Overall Sync State

State

Definition

Locked

Overall PTP State is Locked

Indicates the following:

  • all monitored services are Locked or Synchronized (excluding clockClass)

  • a Secondary PTP source is present and the DU is syncing time from it.

    Note: In scenarios where a secondary PTP source is present, exclude GNSS-State from the overall sync state calculation.

Freerun

Overall PTP State is Freerun

Indicates that any of the PTP services are either in Freerun or non-Synchronized state.

Holdover

Overall PTP State is Holdover

Indicates that the Sync state is not locked, it transitions out of sync state, and the Holdover time does not expire.
Table 2. PTP Lock State

State

Definition

Freerun

Clock is out of sync state

Indicates the following:

  • portState is not “SECONDARY”, the ClockClass value is NOT “6”, or the timeTraceable flag is FALSE

  • holdover time exceeds its provided value

  • ptp4l or phc2sys services are not running and are not accessible

Locked

Clock is in sync state

Indicates that portState is “Primary” or "Secondary", the ClockClass value is “6”, the timeTraceable flag is TRUE, and PMC, ptp4l configuration, ptp4l or phc2sys are accessible.

Holdover

Clock is in holdover state

Indicates that the holdover time does not expire.
Table 3. PTP Clock Class

State

Definition

6

Locked with Primary Reference Clock

Indicates that PMC, ptp4l configuration , ptp4l or phc2sys are accessible.

Note: Determine the clockClass value using the PMC command. If the reading of the value fails, set the clockClass to 248.

7

PRC in holdover mode after losing synchronization

248

Default, if nothing else applies

255

Slave Only Clock
Table 4. OS Clock State

State

Definition

Freerun

Clock is in Freerun

Indicates that the Holdover conditions are met, but the holdover timer expired.

Locked

Clock is in Locked

  • Indicates that Phc2sys is running and discipling the OS clock.

  • Indicates that the OS clock is within 1000ns of expected offset from PHC.

Holdover

Clock is in holdover state

Indicates the following:

  • Holdover timer has not expired

  • phc2sys is not running and not discipling the OS clock

  • OS clock offset is outside of tolerance values
Table 5. GNSS State

State

Definition

SYNCHRONIZED

Indicates the following:

  • ts2phc is running and synchronizing NIC PHC

  • NIC driver DPLL reports GNSS state is locked

ANTENNA-DISCONNECTED

Indicates the following:

  • DPLL is in HOLDOVER state

  • ts2phc is running and synchronizing NIC PHC

FAILURE-NOFIX

Indicates the following:

  • ts2phc is not running and not synchronizing NIC PHC

  • DPLLs are not in LOCKED state