Setting Guidelines - ABB RELION 650 Series Applications Manual

Section 18
Remote communication
The LDCM can also be used together with an external optical to galvanic G.703 converter as
shown in figure 159. These solutions are aimed for connections to a multiplexer, which in turn
is connected to a telecommunications transmission network (for example, SDH or PDH).
*) Converting optical to galvanic G.703
IEC05000527 V2 EN-US
Figure 159: LDCM with an external optical to galvanic converter and a multiplexer
When an external modem G.703 is used, the connection between LDCM and the modem is
made with a multimode fiber of max. 3 km length. The IEEE/ANSI C37.94 protocol is always
used between LDCM and the modem.
18.1.3

Setting guidelines

ChannelMode : This parameter can be set Normal or Blocked . 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
• LDCM for slot 303: Set
RemoteTermNo : This setting assigns a number to each related LDCM in the remote IED. For
each LDCM, the 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
• LDCM for slot 303: Set
330
Multiplexer
*)
TerminalNo to 1 and RemoteTermNo to 2
TerminalNo to 3 and RemoteTermNo to 4
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 shall be set to a different value than parameter
TerminalNo to 2 and RemoteTermNo to 1
TerminalNo to 4 and RemoteTermNo to 3
Telecom. Network
1MRK 505 363-UEN A
Multiplexer
*)
en05000527-2.vsd
M12454-3 v5.1.1
Application manual