Model 922-MES
– User Manual
Focal Technologies Corporation
Page 3-3
A Moog Inc. Company
Document No. 922-0662-00, Rev 1.0
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.
Figure 3-3: Many sensors transmitting via separate or redundant optical links
Figure 3-4: Multiple Modems Optically Multiplexed onto 1 fiber using CWDM
4x SMF
TO SURFACE
ENET
SWITCH
TX1
RX1
TX2
RX2
BACKPLANE
SENSOR 1
SENSOR 2
SENSOR 3
PLC
SERIAL
SERVER
CAT 5e
CAT 5e
CAT 5e
CAT 5e
1x SMF
TO SURFACE
l
1,
l l l
3, 5, 7
8-CHANNEL
CWDM
OPTICAL
MODULE
NODE 1
ENET
SWITCH
TX1
RX1
TX2
RX2
NODE 2
ENET
SWITCH
TX1
RX1
TX2
RX2
l
1
l
2
l
3
l
4
l
5
l
6
l
7
l
8
l
2,
l l l
4, 6, 8
