Setting Guidelines - ABB RET670 Applications Manual

1MRK504116-UUS C
5.1.2
Application manual

Setting guidelines

ChannelMode: This parameter can be set Enabled or Disabled. Besides this, it can be
set OutOfService which signifies that the local LDCM is out of service. Thus, with this
setting, the communication channel is active and a message is sent to the remote IED
that the local IED is out of service, but there is no COMFAIL signal and the analog
and binary values are sent as zero.
TerminalNo: This setting shall be used to assign an unique address to each LDCM, in
all current differential IEDs. Up to 256 LDCMs can be assigned a unique number.
Consider a local IED with two LDCMs:
• LDCM for slot 302: Set TerminalNo to 1 and RemoteTermNo to 2
• LDCM for slot 303: Set TerminalNo to 3 and RemoteTermNo to 4
In multiterminal current differential applications, with 4 LDCMs in each IED, up to 20
unique addresses must be set.
The unique address is necessary to give high security against incorrect
addressing in the communication system. Using the same number for
setting TerminalNo in some of the LDCMs, a loop-back test in the
communication system can give incorrect trip.
RemoteTermNo: This setting assigns a number to each related LDCM in the remote
IED. For each LDCM, the parameter RemoteTermNo shall be set to a different value
than parameter TerminalNo, but equal to the TerminalNo of the remote end LDCM. In
the remote IED the TerminalNo and RemoteTermNo settings are reversed as follows:
• LDCM for slot 302: Set TerminalNo to 2 and RemoteTermNo to 1
• LDCM for slot 303: Set TerminalNo to 4 and RemoteTermNo to 3
The redundant channel is always configured in the lower position, for
example
• Slot 302: Main channel
• Slot 303: Redundant channel
The same is applicable for slot 312-313 and slot 322-323.
DiffSync: Here the method of time synchronization, Echo or GPS, for the line
differential function is selected.
Section 5
Remote communication
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