monitoring/collectd-extensions/src/ptp.conf

<Plugin "threshold">
  <Plugin "ptp">
    <Type "time_offset">
      Instance "nsec"
      Persist true
      PersistOK true
      WarningMax 1000
      FailureMax 1000000
      WarningMin -1000
      FailureMin -1000000
      Invert false
    </Type>
  </Plugin>
</Plugin>