ABB Relion 670 Series Applications Manual page 556

Section 21
Remote communication
• LDCM for slot 305: set
• LDCM for slot 306: set
In multiterminal current differential applications,with 4 LDCMs in each IED, up to 20 unique
addresses must be set.
RemoteTermNo is used to assign a number to each related LDCM in the remote IED. For each
LDCM, RemoteTermNo is set to a different value than TerminalNo , but equal to the TerminalNo of
the remote end LDCM. In the remote IED,
• LDCM for slot 305: set
• LDCM for slot 306: set
DiffSync defines the method of time synchronization for the line differential function: Echo or GPS .
GPSSyncErr : when GPS synchronization is lost, synchronization of the line differential function
continues for 16 s based on the stability in the local IED clocks. After that, setting
line differential function or setting
CommSync defines the Master and Slave relation in the communication system, and should not be
mistaken for the synchronization of line differential current samples. When direct fiber is used,
one LDCM is set as
is always set as
OptoPower has two settings: LowPower and HighPower .
Short-range LDCM: Use
Medium-range LDCM: Typical distance 80 km for both
550
TerminalNo to 1 and RemoteTermNo to 2
TerminalNo to 3 and RemoteTermNo to 4
A unique address is necessary to give high security against incorrect addressing in
the communication system. If the same number is used for
the LDCMs, a loop-back test in the communication system can give an incorrect
trip.
TerminalNo to 2 and RemoteTermNo to 1
TerminalNo to 4 and RemoteTermNo to 3
The redundant channel is always configured to the lower position, for example:
• Slot 305: main channel
• Slot 306: redundant channel
The same is applicable for slot 312-313 and slot 322-323.
Echo in this case is safe only if there is no risk of varying transmission
Using
asymmetry.
Echo keeps it on by using the Echo synchronization method.
Echo in this case is safe only if there is no risk of varying transmission
Using
asymmetry.
Master and the other as Slave . When a modem and multiplexer is used, the IED
Slave because the telecommunication system provides the clock master.
LowPower for fibers 0 – 1 km and HighPower for fibers greater than 1 km.
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TerminalNo and RemoteTermNo are reversed as follows:
LowPower and HighPower .
1MRK 511 401-UUS F
TerminalNo in some of
Block blocks the
Bay control REC670
Application manual