LDCMLD CMLDCMLDCMLDCMLD CMLDCMLDCMLD CMLD CMLDCMLDCMLDCMLDCMLDCMLDCMen06000519-2.vsdIEC06000519 V2 EN-USFigure 165: Direct fiber optical connection between two IEDs with LDCMThe LDCM can also be used together with an external optical to galvanic G.703converter as shown in figure 166. These solutions are aimed for connections to amultiplexer, which in turn is connected to a telecommunications transmissionnetwork (for example PDH).Telecom. Network*) *)Multiplexer Multiplexeren05000527-2.vsd*) Converting optical to galvanic G.703IEC05000527 V2 EN-USFigure 166: LDCM with an external optical to galvanic converter and amultiplexerWhen an external modem G.703 is used, the connection between LDCM and themodem is made with a multimode fiber of max. 3 km length. The IEEE/ANSIC37.94 protocol is always used between LDCM and the modem.19.1.3 Setting guidelines M12454-3 v7ChannelMode 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 tothe remote IED that the local IED is out of service. However, no COMFAIL signalexists and the analog and binary values are sent as zero.1MRK 505 393-UEN B Section 19Remote communicationLine differential protection RED650 2.2 IEC 395Application manual
