ABB Relion 670 series - Time Synchronization Using IRIG-B

restart time after a short GPS interruption. If time deviation after the interruption is
less than the set MaxtDiffLevel, the protection function can be enabled directly.
In the case of GPS interruption, the protection function is disabled or echo timing
is enabled as a back-up synchronization method. Enabling echo timing has a delay
which depends on how long the GPS system has been in service after start.
Inaccuracy of the internal clock starts at 16 μs and goes down to ±1μs after some
minutes.
In telecommunication networks with unspecified route switching, echo timing can
only be used with unchanged time delay in both directions. As soon as the time
delay is outside the set limits, the protection function gets blocked. Some additional
features are available to increase the performance of echo timing:
• If redundant or alternative routes are available, they are also supervised for
changes in time delay. If no time delay difference is observed in these routes,
echo timing continues to use the reserve channel.
• In telecommunication networks with unspecified route switching, time
deviations below the set limits are accumulated to handle multiple route
switching, and these accumulated deviations can reach the set time deviation
limit.
3.3 Time synchronization using IRIG-B
GUID-16212191-F952-4155-80C3-3B2245998311 v1
Time synchronization can be provided via IRIG-B 00X with IEEE1344 support.
This setting can be done via PCM600 (see Figures 11 and 12).
Procedure:
1. Set Fine SyncSource = IRIG-B.
2. Set SynchType = Opto (default).
3. Set Encoding = 1344.
4. Select a value for TimeZoneAs1344, for example, to enable tagging of events
using the real time clock.
IEC10000064 V1 EN-US
Figure 11: Setting IRIG-B as the synchronization source
Section 3 1MRK 505 382-UEN B
Common time synchronization
24 Communication set-up 670/650 series 2.2
Application Guide