Furuno FI-304 Operator's Manual page 24

When using the Compass Data in a Network with more than 3 transducers, we
recommend you to use the FI-30 Server. One Nexus Network power/data cable is used
to connect all instruments. You will have NMEA 0183 in/out. Depth information will (if
used) be repeated at more than one FI-30 instrument.
Network bonus function:
When you are using the race timer on the Multi or Log
instrument, a graphical countdown timer will pop up the last 60
seconds.
In this example there is 45 seconds to the start.
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