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Configuring the Oscillator

VersaPNT is equipped with an internal oscillator (see also the previous topics Managing the Oscillator). To configure the oscillator settings:

  1. Navigate to MANAGEMENT > OTHER: Disciplining.
  2. Click the GEAR icon at the top of the Status panel. The Oscillators Settings window will display:
  3. Populate the fields:
    • Maximum TFOM for Sync: When TFOM (Time Figure of Merit, see also Time Figure of Merit (TFOM)) is greater than Max TFOM, disciplining will still be attempted against the selected reference to improve the TFOM. If the condition persists, the system will transition to holdover, and eventually out of sync. When disciplining is performed such that TFOM is no longer greater than max TFOM, the system will transition back into sync.
    • Holdover Timeout(s): The default is 7200 s (= 2 hours).
      For more information on holdover timeouts, see Typical Holdover lengths in seconds. For additional information on holdover, see What is "Holdover Timeout"?.
    • Phase Error Limit: [Default=0 (disables this feature)]. Setting a Limit (valid for +/-) for the Phase Error between an external 1PPS reference and the System 1PPS will cause the disciplining tracking to restart automatically (after a few minutes delay) if that limit is exceeded. This will help to quickly re-align the System 1PPS with a reference.
    • When using a Host Reference as a primary or backup reference, for improved performance it is recommended to set the phase error limit for NTP to a suggested value of 100000 ns (= 1 µ second). Adjust this value as needed, based on your accuracy requirements.

    • Restart Tracking: Check this box, and click Submit if you want to manually restart disciplining tracking.
      This option causes the disciplining algorithm to stop tracking the input reference and start over (as if it was just acquired). This can be useful if there is a large phase offset between reference 1PPS and system 1PPS, as it may occur when going back into sync to the external reference after a long holdover. A Restart Tracking will re-align the system 1PPS with the reference 1PPS very quickly, but may cause the 1PPS output to jump.
    • Recalibrate: In rare cases, existing calibration data may no longer be suitable to calibrate the oscillator. This function will delete the existing calibration data, and begin a new calibration process (not applicable for low phase-noise Rubidium oscillators).
  4. Click Submit.