5700MSC-IP
IP Network Grand Master Clock & Video Master Clock System
Page - 26 Revision 0.2
Table 3-3: Genlock Range Characteristics
The status of the reference and lock progress can be monitored on the Lock Status screen, accessed
by pressing the STATUS button and selecting Lock Status. The current position within the tuning
range of the selected oscillator is shown as OCXO center or WIDE center. It is displayed as a
percentage (+100% to –100%) of the total tuning range. This reading gives an idea of how close to the
edges of the tuning range the oscillator is when locked to a reference.
The Narrow range OCXO oscillator ages over time and the center frequency may drift. It is important
that despite any drift it retains the ability to lock to a precision frequency source such as GNSS or a
rubidium/cesium frequency standard. Such frequency sources are extremely accurate. The oscillator is
guaranteed from the factory to lock to such a reference within ±10% of the center of its tuning range.
The aging of the oscillator is 10% maximum for the first year, and 5% for every year thereafter. This
translates to an expected lifetime of 15 years. If the oscillator locks at over ±90% of its tuning range, a
warning condition will be indicated and the status line will be shown in Red. Keep in mind that the
OCXO center value is only meaningful when locked to a very accurate frequency reference.
The 5700MSC-IP monitors the condition of both oscillators at all times. If an oscillator problem is
detected, the unit will seamlessly switch to the unused oscillator and report an internal hardware fault.
This will activate the Hw Fail message on the front panel and can also send out an SNMP trap. If such
a fault occurs, it is not advisable to power down or attempt to restart the unit. Contact Evertz customer
service for further assistance at +1 905-335-7570 or see
www.evertz.com/support.
3.2.4. Lock Type Selection
When the Genlock Range is set to Narrow, the Lock Type controls how the 5700MSC-IP will respond
when its oscillator becomes out of sync to the frequency reference. This situation can occur if the
incoming frequency reference changes or is reconnected after a period of absence long enough that
the 5700MSC-IP oscillator has drifted and is no longer synchronized. There are two lock types
available: Slow and Abrupt.
In the Abrupt mode, the 5700MSC-IP will respond to any change in the incoming frequency reference
with an immediate re-lock, shifting the timing of the unit to match the reference. This effect will ripple to
the outputs and may cause undesired effects in downstream equipment, depending on the amount of
correction performed. This is the default mode of operation. When the Genlock Range menu item is
set to Wide, the relocking mode is always Abrupt, regardless of the Lock Type menu setting.
When the Slow lock mode is selected, the 5700MSC-IP will detect when its oscillator is not
synchronized to the reference and issue a frequency reference unlocked warning. It will display REF
JAM NEEDED on the left LCD display and can also be configured to send out an SNMP trap. It will
then gradually adjust the frequency of the OCXO, limiting the rate of change, until the oscillator is
brought back into sync with the incoming reference. Once this “slow” re-lock process is complete, the
“REF JAM REQUIRED” warning will be cleared. The Lock progress display will return to 100% and the
unit will continue normal operation.
The Slow lock type can take a long time to relock to the reference signal, especially when
correcting for a large discrepancy in phase. It takes about a minute to correct for a phase
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