What is the redundancy or backup for integrated electronic systems that all share the same network? I have been wondering about this and would like to pose a few questions for anyone who would like to jump in.
My background is in aviation where integrated electronics
has become common but not without two or more degrees of redundancy or backup at every level. Essential instruments have their own network and are not allowed on the main network. Is there any such thing in the design of marine
For example, a NMEA 2000
network is a four wire cable with two signal wires and two power wires for all the instruments on the bus. If the power wires loose power, then everything goes dead? True? Is anyone installing these networks with alternative power source or are there any networks that make a provision for this?
I see these networks sometimes go up the mast
to masthead instruments. If you get dismasted then what? Wouldn't that also break the network cable and cause you to loose position, heading, radar
and maybe even engine
Do those of you with these systems still have a magnetic compass
Is is possible for a device, connector, terminator or something on the network to fail and bring everything down with it? How do you troubleshoot this or is anyone installing these systems with some kind of redundancy and what is that?
Do you carry spare parts
for the network? Spare cable, connectors, terminator resistors, etc?
Do these networks have any kind of built-in lightning
protection? Are they being installed with external lightning
What if the boat takes on water
? Is the routing of the network cable and all the exposed connectors (i.e. N2K depth sounder
sensor) immune to this?
It looks to me like an increasing number of boats are being equipped with these integrated systems and nothing else. If anyone has given any thought to this, I'd like to hear your reasoning.