ABB Relion 670 series, Technical Reference Manual

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Synchronization via IRIG-B
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 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 1-7.
“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 x is 0, 1, 2 or 3, the information contains only the time
within the year, and year information has to come from 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.
It is recommended to use IEEE 1344 for supplying time information to the IRIG-B
module. In this case, send also the local time in the messages, as this local time plus
the TZ Offset supplied in the message equals UTC at all times.
4.3.2.4 Process bus IEC 61850-9-2LE synchronization
For the time synchronization of the process bus communication (IEC 61850-9-2LE
protocol) an optical PPS or IRIG-B signal can be used. This signal should emanate
from either an external GPS clock, or from the merging unit.
An optical PPS signal can be supplied to the optical interface of the IRIG-B module.
4.3.3 Function block
IEC05000425-2-en.vsd
TIMEERR
TSYNCERR
RTCERR
IEC05000425 V2 EN
Figure 28: TIMEERR function block
1MRK505222-UUS C
Section 4
Basic IED functions
91
Technical reference manual