Signals - ABB 615 series Technical Manual

Section 3
Basic functions
3.5.1.3
[1] The line differential protection is available only in RED615.
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When Modbus TCP or DNP3 over TCP/IP is used, SNTP or IRIG-B time
synchronization should be used for better synchronization accuracy.
With the legacy protocols, the synchronization message must be received
within four minutes from the previous synchronization. Otherwise bad
synchronization status is raised for the protection relay. With SNTP, it is
required that the SNTP server responds to a request within 12 ms,
otherwise the response is considered invalid.
The relay can use one of two SNTP servers, the primary or the secondary server. The
primary server is mainly in use, whereas the secondary server is used if the primary server
cannot be reached. While using the secondary SNTP server, the relay tries to switch back
to the primary server on every third SNTP request attempt. If both the SNTP servers are
offline, event time stamps have the time invalid status. The time is requested from the
SNTP server every 60 seconds. Supported SNTP versions are 3 and 4.
IRIG-B time synchronization requires the IRIG-B format B004/B005 according to the
200-04 IRIG-B standard. Older IRIG-B standards refer to these as B000/B001 with
IEEE-1344 extensions. The synchronization time can be either UTC time or local time. As
no reboot is necessary, the time synchronization starts immediately after the IRIG-B sync
source is selected and the IRIG-B signal source is connected.
IRIG-B time synchronization requires a COM card with an IRIG-B input.
When using line differential communication between RED615 protection relays, the time
synchronization messages can be received from the other line end protection relay within
the protection telegrams. The protection relay begins to synchronize its real-time clock
with the remote end protection relay's time if the Line differential time synchronization
source is selected. This does not affect the protection synchronization used in the line
differential protection or the selection of the remote end protection relay's time
synchronization method.

Signals

Table 28: GNRLLTMS output signals
Name
ALARM
WARNING
[1]
Type
BOOLEAN
BOOLEAN
1MAC059074-MB A
Description
Time synchronization alarm
Time synchronization warning
615 series ANSI
Technical Manual