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en06000519-2.vsd
IEC06000519 V2 EN-US
Figure 165: Direct fiber optical connection between two IEDs with LDCM
The LDCM can also be used together with an external optical to galvanic G.703
converter as shown in figure 166. These solutions are aimed for connections to a
multiplexer, which in turn is connected to a telecommunications transmission
network (for example PDH).
Telecom. Network
*) *)
Multiplexer Multiplexer
en05000527-2.vsd
*) Converting optical to galvanic G.703
IEC05000527 V2 EN-US
Figure 166: 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.
19.1.3 Setting guidelines
M12454-3 v7
ChannelMode can be set to Normal or Blocked. It can also be set to OutOfService.
In that case, the communication channel remains active, and a message is sent to
the remote IED that the local IED is out of service. However, no COMFAIL signal
exists and the analog and binary values are sent as zero.
1MRK 505 393-UEN B Section 19
Remote communication
Line differential protection RED650 2.2 IEC 395
Application manual
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