Clock source

The Clock Source setup register defines the meter’s representation of a one second period, and can be set to:

Setting option Description
Line Frequency

The meter monitors the ISO Grid Operation line frequency, and adjusts the one second period based on the measured line frequency. All devices connected to the grid network are synchronized to maintain a consistent time base. If a power outage occurs, the clock automatically synchronizes with the meter’s internal crystal until power is restored. Once power is restored, the clock resynchronizes with the line frequency.

Note: Do not use line frequency when your meter is synchronized to an external time sync source.
Internal

The meter clock is synchronized to the meter’s internal crystal.
Comm

The meter clock is synchronized to an external time sync source. Use this for the Clock Source if:

  • The Time Sync Source setup register is set to a serial communications port to receive GPS time synchronization signals.
  • The Time Sync Source setup register is set to ethernet-ptp and your meter is installed in a trusted PTP network.
  • The Time Sync Source setup register is set to irig-b.