Fiber Optic Considerations; Fiber Optic Cable Compatibility; Optical Bypass Relay - Motorola MPMC221 Installation And Use Manual

Fiber Optic Considerations

Fiber Optic Cable Compatibility

Any standard small configuration (SC) cable assembly is
compatible with the MPMC221/MPMC222, if the
station-connection terminal has two standard Media Interface
Connectors (MIC) with a fixed shroud enclosure.

Optical Bypass Relay

An external Optical Bypass Relay (OBR) is used for DAS fiber
configurations with the MPMC222. The OBR is controlled by the
host.
The OBR is installed between a MPMC222 and the FDDI network.
The OBR protects the network from possible link failures due to
station failures, by switching the network data stream to bypass the
attached station after the OBR detects a power failure in that
station. Without this bypass, the entire network will be affected by
the failure, forcing the neighboring stations to reconfigure.
One two-by-two unit provides the FDDI LAN primary and
secondary data ring with a fully-reversing optical bypass switch.
Switching to bypass mode takes less than 10ms. The bypass relay
and the MPMC222 join in three physical locations:
To allow bypass-to-network connection, two standard SC
receptacles with bulkhead adapters are located on the network end
of the unit. The receptacles accept two standard fixed shroud
duplex optical fiber cables, one for each FDDI data ring.
Figure 1-4
one central optical bypass control cable drives the switching
operation
two standard SC cables, one for each transmit and receive
pair, connect the fiber media
shows the operation of the OBR.
Fiber Optic Considerations
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