Setting Guidelines - Hitachi Relion 670 Series Applications Manual

1MRK511407-UUS Rev. N
IEC06000519 V2 EN-US
Figure 125:
The LDCM can also be used together with an external optical to galvanic G.703 converter as shown in
figure 126. These solutions are aimed for connections to a multiplexer, which in turn is connected to a
telecommunications transmission network (for example PDH).
*) Converting optical to galvanic G.703
IEC05000527 V2 EN-US
Figure 126:
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/2 mile length. The IEEE/ANSI C37.94 protocol is always used between
LDCM and the modem.
20.1.3

Setting guidelines

64 kbit mode common settings
ChannelMode defines how an IED discards the LDCM information when one of the IEDs in the system is
out of service: it can either be done on the IED out of service by setting all local LDCMs to channel mode
OutOfService or at the remote end by setting the corresponding LDCM to channel mode Blocked. If
OutOfService is selected, the IED should have active communication to the remote end during the whole
maintenance process, that is, no restart or removal of the fiber can be done.
This setting does not apply to two-end communication.
Phasor measurement unit RES670
Application manual
Direct fiber optical connection between two IEDs with LDCM
Multiplexer
*)
LDCM with an external optical to galvanic converter and a multiplexer
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Telecom. Network
Remote communication
en06000519-2.vsd
Multiplexer
*)
en05000527-2.vsd
Section 20
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