Setting Guidelines - ABB REC670 Applications Manual

1MRK 511 401-UEN A
21.1.3
Bay control REC670 2.2 IEC
Application manual
IEC06000519 V2 EN-US
Figure 240: Direct fibre 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 241. These solutions are aimed for connections to a
multiplexer, which in turn is connected to a telecommunications transmission
network (for example PDH).
Multiplexer
*) Converting optical to galvanic G.703
IEC05000527 V2 EN-US
Figure 241: 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 fibre of max. 3 km length. The IEEE/ANSI
C37.94 protocol is always used between LDCM and the modem.

Setting guidelines

64 kbit and 2 Mbit 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
Telecom. Network
*)
Section 21
Remote communication
en06000519-2.vsd
Multiplexer
en05000527-2.vsd
*)
M12454-3 v6
569