GE B90 Instruction Manual page 243

CHAPTER 5: SETTINGS
When the relay does not have the IEEE 1588 software option and this setting does not display, it uses IRIG-B when enabled
and operational, then failing that SNTP when configured and operational, and otherwise it free-runs unless the clock is
changed from the front panel or from communications protocols.
Setup for IRIG-B is illustrated in the Installation chapter.
For the Other protocols, whenever a time synchronization message is received through any of the active protocols, the B90
clock updates. However, given that IEC 60870-5-103, IEC 60870-5-104, Modbus, and DNP are low-accuracy time
synchronization methods, avoid their use for synchronization when better accuracy time protocols, such as IRIG-B and PTP,
are active in the system. If IRIG-B or PTP is used to update the relay clock, the other protocols (such as SNTP) are not
allowed to update, even if active.
See the
COMMANDS  SET DATE AND TIME
The setting allows changes to the date and/or time to be captured in the event record. The event
REAL TIME CLOCK EVENTS
records the RTC time before the adjustment. A Date/Time Changed event is generated when:
• The real time clock changed from SNTP/PTP/IRIG-B and the time difference is more than one second
• The real time clock changed from the front panel or via Modbus register. The relay always generates this event
regardless of the time difference.
• The Daylight Saving Time (DST) setting gets enabled and the current relay time is already in the DST zone
• The real time clock enters or leaves DST
To enable IRIG-B synchronization, the input
synchronization can be disabled by making this setting None.
To configure and enable PTP and/or SNTP, or to set local time parameters (for example time zone, daylight savings), use the
following sections.
5.3.7.2 Precision time protocol (1588)
SETTINGS  PRODUCT SETUP  REAL TIME CLOCK  PRECISION TIME PROTOCOL (1588)
 PRECISION TIME
 PROTOCOL (1588)
SETTINGS  PRODUCT SETUP  REAL TIME CLOCK  PRECISION TIME PROTOCOL (1588)  PTP PORT 1(3)
 PTP PORT 1

The B90 is provided with optional Precision Time Protocol capability. This feature is specified as the IEEE 1588
software option at the time of ordering. See the Order Codes section in chapter 2 for details.
B90 LOW IMPEDANCE BUS DIFFERENTIAL SYSTEM – INSTRUCTION MANUAL
menu section of this manual to manually set the RTC.
must be set to DC Shift or Amplitude Modulated. IRIG-B
IRIG-B SIGNAL TYPE
STRICT POWER

PROFILE: Disabled
PTP DOMAIN NUMBER:

0
PTP VLAN PRIORITY:

4
PTP VLAN ID:

0
 PTP PORT 1


PORT 1 PTP FUNCTION:

Disabled
PORT 1 PATH DELAY

ADDER: 0 ns
PORT 1 PATH DELAY

ASYMMETRY: 0 ns
Range: Enabled, Disabled
Range: 0 to 255
Range: 0 to 7
Range: 0 to 4095
See below
Range: Enabled, Disabled
Range: 0 to 60000 ns in steps of 1
Range: –1000 to +1000 ns in steps of 1
PRODUCT SETUP
5
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