Example Optical Topologies; Figure 3-3: Many Sensors Transmitting Via Separate Or Redundant Optical Links; Figure 3-4: Multiple Modems Optically Multiplexed Onto 1 Fiber Using Cwdm - Focal 922-MES User Manual

3.1 Example Optical Topologies

The Ethernet switch-based architecture and the configuration adopted for the 922-MES can be used to satisfy
a number of different subsea operational requirements.
For example, more than one MES Ethernet modem can be used to provide full card redundancy. Alternatively,
configuring each card to connect to separate copper Ethernet devices provides additional throughput capacity.
Lastly, connecting a copper Ethernet channel between two modems (i.e. electrically daisy-chaining the second
card), can provide a second pair of optical connections for other subsea nodes. With RSTP functionality enabled
in the MES the copper ports can also be used to electrically daisy chain multiple cards using multiple copper
ports. The figures below illustrate some alternative optical topologies supported by this modem.
4x SMF
TO SURFACE

Figure 3-3: Many sensors transmitting via separate or redundant optical links

l1, l
1x SMF
TO SURFACE
l2, l

Figure 3-4: Multiple Modems Optically Multiplexed onto 1 fiber using CWDM

Focal Technologies Corporation
A Moog Inc. Company
TX1
RX1
TX2
RX2
8-CHANNEL
l l
3, 5, 7
CWDM
l l OPTICAL
4, 6, 8
MODULE
BACKPLANE
ENET
SWITCH
CAT 5e
Document No. 922-0662-00, Rev 1.0
Model 922-MES – User Manual
CAT 5e
SENSOR 1
CAT 5e
SENSOR 2
SENSOR 3
SERIAL
SERVER
CAT 5e
PLC
NODE 1
l1
TX1
l2
RX1
ENET
l3
SWITCH
TX2
l4
RX2
NODE 2
l5
TX1
l6
RX1
ENET
l7
SWITCH
TX2
l8
RX2
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