Fibre Optic Loop - ABB REL670 Installation And Commissioning Manual

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Fibre optic loop

Fibre optic loop
The SPA communication is mainly used for SMS. It can include different numerical relays/ter-
minals with remote communication possibilities. The fibre optic loop can contain < 20-30 ter-
minals depending on requirements on response time. Connection to a personal computer (PC)
can be made directly (if the PC is located in the substation) or by telephone modem through a
telephone network with ITU (CCITT) characteristics.
Table 7: Max distances between terminals/nodes
glass < 1000 m according to optical budget
plastic < 25 m (inside cubicle) according to optical budget
Remote monitoring
system with
PCM600
Teleph Teleph
one one
modem modem
Where:
A separate minute pulse synchronization from station clock to obtain ± 1 ms accuracy for
1
time tagging within the substation might be required.
Figure 23: Example of SPA communication structure for a station monitoring system
Local monitoring
system with
PCM600
IED670
Optical to electrical
converter, e.g. SPA-ZC 22
or Fiberdata modem
Chapter 8
Establishing connection and
verifying the
SPA/IEC-communication
IED670 IED670
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