ABB S800 - Page 33

Section 2 Product Description Communication
3BSE015969-600 A 33
• star configuration with the Optical Media Converter. See Figure 12.
Figure 10. Optical ModuleBus and I/O Clusters, Simplex
Communication
Cluster 1
TB820
Cluster 2
TB820
Cluster 3
TB820
Cluster 7
TB820
Rx Rx
Rx Rx
Tx
Tx
TxTx
Rx
Tx
I/O Station
Maximum length of any cable is:
15 m (49 ft.) for plastic fiber
200 m (667 ft.) for HCS glass fiber
• Simplex provides a one-way ring connection from the FCI to the modem, to the
second modem, etc., and back from the last modem to the FCI.
• Duplex provides a two-way connection, and is normally the best
communication design.
• Duplex allows additional modems to be added do
wn-stream on-line.
• A cable break or loss of a modem will only affect I/O clusters down-stream of
the f
ailure.
Figure 11. Optical ModuleBus and I/O Clus
ters, Duplex Communication
Cluster 1
TB820
Cluster 2
TB820
Cluster 3
TB820
Cluster 7
TB820
Rx Rx
Rx Rx
Tx
Tx
TxTx
Rx
Tx
I/O Station
Maximum length of any cable is:
15 m (49 ft.) for plastic fiber
200 m (667 ft.) for HCS glass fiber
Tx Tx TxRx
Rx
Rx