ABB AC 800M, User Manual

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Section 2 Transmission Technology Basics of fibre optics topology technologies
3BDS009029R5001 B 47
Line Topology
In a line structure, the individual optical link modules are connected together by
dual-fiber optical fibers (transmit/receive fibres). Modules with one optical port are
sufficient at the beginning and end of a line, between then modules with two optical
ports are necessary. If single point-to-point connections are to be built up, this can
be achieved using two modules each with one optical port.
This operating mode should preferably be used if an interrupted fiber segment is to
be separated from the rest of the network.
The following monitoring mechanisms shall be set on the optical link modules:
• Send echo: yes
• Monitor echo: yes
• Suppress echo: yes
• Monitor: yes
• Segmentation: yes
In this operating mode the individual fiber links are monitored by the two connected
modules.
Figure 10. Network structure in an optical line topology