8 SERIES PROTECTIVE RELAY PLATFORM – COMMUNICATIONS GUIDE
3-1
8 Series Protective Relay Platform
Chapter 3: Time Protocols
GE
Grid Solutions
Time Protocols
Real-time Clock
Path
:
Setpoints > Device > Real Time Clock
The 8 Series relay is capable of receiving a time reference from several time sources in
addition to its own internal clock for the purpose of time-stamping events, transient
recorders and other occurrences within the relay. The accuracy of the time stamp is based
on the time reference that is used. The 8 Series relay supports an internal clock, SNTP, IRIG-
B, and PTP IEEE 1588 as potential time references.
If two or more time sources are available, the time source with the higher priority shown in
Time Sources table is used where 1 is considered to be the highest priority. Please note
that the time source priority of PTP and IRIG-B can be swapped. If both PTP and IRIG-B are
available to the 8 Series relay, by default the 8 Series relay clock syncs to PTP over IRIG-B.
If PTP is not available the 8 Series relay CPU syncs the internal clock to IRIG-B.
Table 3-1: Time Sources
* The priority of IRIG-B and PTP can be swapped.
FASTPATH:
Synchronization by IEC103, DNP, Modbus and IEC104 is not going to be issued if there is a
sync source from IRIG-B, SNTP or PTP.
Time Source
Priority
PTP (IEEE1588)
1*
IRIG-B
2*
SNTP
3
Internal Clock
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