4.
Setup Holdover Timeout
Use the holdover time settings to configure the maximum time in seconds the GridTime 3000 will remain in the
'holdover' state after losing all of its sync sources before entering the 'out of sync' state. When in the 'holdover'
state, the GridTime 3000 relies on its internal oscillator in free run mode as a time reference. The accuracy
of the oscillator time reference will slowly degrade as the oscillator drifts. This slow decline in accuracy during
holdover is tracked by the accuracy reported in the GridTime 3000's outputs. If a rubidium or OCXO (Oven
Controlled Crystal) Oscillator expansion is fitted in the GridTime 3000, the oscillator time will drift slower than
the time drift of the base VCTCXO (Voltage Controlled, Temperature Compensated crystal) Oscillator that is
fitted.
Once the holdover time has expired, the GridTime 3000's time will be considered too inaccurate to be usable
and the GridTime 3000 will enter the 'out of sync' state. In the 'out of sync' state the GridTime 3000 will still rely
on its oscillator as a reference, but will trigger the out of sync alarm and and will trigger the indication of out of
sync on outputs that have a specific out of sync indicator, such as PTP clockClass .
The GridTime 3000 can resynchronize to a sync source if it becomes available when in the 'holdover' or 'out of
sync' states, which makes it reenter the 'in sync' state.
To use holdover timeout, select 'USE HOLDOVER TIMEOUT' with the holdover timeout radio buttons. You can
then enter the time you want the GridTime 3000 to remain in holdover after losing its sync sources with the
'HOLDOVER TIME IN SECONDS' textbox.
Provisioning
©
2022 Microchip Technology Inc.
and its subsidiaries
Manual
DS00004572A-page 67
