ABB RELION 670 Series Technical Manual page 1258

Section 21
Basic IED functions
time will drift by maximum the error rate in the internal clock. If the minute pulse is returned, the
first pulse is automatically rejected. The second pulse will possibly be rejected due to the spike
filter. The third pulse will set the time if the time offset is more than 500 ms or adjust the time if
the time offset is small enough. If the time is set, the application will be brought to a safe state
before the time is set. If the time is adjusted, the time will reach its destination within one minute.
Synchronization via IRIG-B module
IRIG-B is a protocol used only for time synchronization. A clock can provide local time of the year in
this format. The "B" in IRIG-B states that 100 bits per second are transmitted and the message is
sent every second. After IRIG-B there are numbers stating if and how the signal is modulated and
the information transmitted.
To receive IRIG-B there are two connectors in the IRIG-B module, one galvanic BNC connector and
one optical ST connector. IRIG-B 12x messages can be supplied via the galvanic interface, and IRIG-
B 00x messages can be supplied via either the galvanic interface or the optical interface, where x
(in 00x or 12x) means a number in the range of 0-7.
"00" means that a base band is used, and the information can be fed into the IRIG-B module via the
BNC contact or an optical fiber. "12" means that a 1 kHz modulation is used. In this case the
information must go into the module via the BNC connector.
If the x in 00x or 12x is 4, 5, 6 or 7, the time message from IRIG-B contains information of the year.
If the x is 0, 1, 2 or 3, the information contains only the time within the year, and year information
has to be set via PCM600 or local HMI.
The IRIG-B module also takes care of IEEE1344 messages that are sent by IRIG-B clocks, as IRIG-B
previously did not have any year information. IEEE1344 is compatible with IRIG-B and contains year
information and information of the time-zone.
21.1.3.4 Process bus IEC 61850-9-2LE synchronization
When process bus communication (IEC 61850-9-2LE protocol) is used, it is essential that the
merging units are using the same time source as the IED. To achieve this, a satellite-controlled
clock shall provide time synchronization to the IED (either internal GPS or via IRIG-B 00x with
IEEE1344 support) and to the merging units (via for instance PPS). For the time synchronization of
the process bus communication, GPS Time Module (GTM) and/or IRIG-B module can be used. If the
IED contains a GTM, the merging unit can be synchronized from the PPS output of the GTM.
21.1.4 Technical data
Table 968: Time synchronization, time tagging
Function
Time tagging resolution, events and sampled measurement values
Time tagging error with synchronization once/min (minute pulse synchronization),
events and sampled measurement values
Time tagging error with SNTP synchronization, sampled measurement values
1252
1MRK 502 066-UUS B
M11346-146 v8
GUID-6E384BDB-5598-4108-99B4-0B4A4E1828B2 v3
IP9658-1 v1
M12331-1 v7
Value
1 ms
± 1.0 ms typically
± 1.0 ms typically
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