Fiber optic for boat data networks

[alanvee]

Originally Posted by mgrouch

Why fiber optic cabling is not a choice for boat data networks? Thin cable, isolated, great bandwidth, no heating issue, less fire hazard.
Seems could have been good choice

Why do you need great bandwidth? N2K is only 250kbits/sec which is very low bandwidth, 0183 is even lower. Only reason I can see at the moment might be if you are sending video, radar or a sonar signal. These three can be sent over NMEA OneNet, an IP based system running at 10Mbits to 10Gbits/sec using standard network twisted pair cable. Onwa use this data system to transfer data and to send radar and sonar on their latest plotter and radar products.

[kubota]

i use fiber optic cable in off grid application. buried cat5e for some reason is lightning magnet.
lost 3 buried 400ft runs burned in half in 15 yrs.

i also consult on fiber systems for ISPs.

i bought
- consumer grade
-multimode only
-field attachable connector
kit i pieced together for $500.

it will give sufficient quality for <1 gigabit/s nets
at distances of 200 meters.

connectors are $10 apiece.
multi mode dual fiber cable (gotta have 2 strands per circuit so 4 connectors. muxes like commercial use are too expensive).

2 strand multimode is $250 for 1000 ft.

count on munging up bout 2 out of every 5 connectors with this grade of gear. no spicing, use connectors with end to end joiner.

SFPs to terminate fiber, one per end, are bout $40 apiece. upgraded ubiquiti switch to bridge elec to fiber adds another $150.

so for around $1000 plus connectors you can do your boat in fiber yourself.

however, i dont use it afloat, only ashore.
- optical interfaces suck power. my idle current at 12v is 2 amps. 24x7 for 1 drop.
-it hates vibration. particularly the connectors. must be rigid to same vibration plane as equipment its attached to. and i mean rigid.
- min bend radius 3". 8" preferred.
- and for god sake dont stress it while pulling it. elongated fibers, twists, or breaks on the strand and now you have junk.
- fragile as hell. proper outdoor stuff like corning makes each drop is going to cost $300/end if you have a $6000 fusion splicer.

wait for a prefab drop and equipment with direct fiber interface like in home video is my recco. it will be ruggidized and hopefully they will do something bout power consumption.

[kubota]

p.s. fs.com sells military grade pre connectorized simplex cables (need two per drop) in multiples of 5m length for $30 apiece.
alloy steel and tpm jacket.
at $60/ drop its more expensive but a bargain if u arent confident in splicing.
just bulkier and dont know how well the alloy is isolated for marine use.
still need all the other stuff, but this is at least ruggedized.

as a warning, this isnt corning gear at this price.
all china.

[kubota]

well this thread just died.

[Trawlerman]

R.I.P.

[kubota]

i feel like i just killed Kenny.
im sure the question will be back next episode. .

[team karst]

With a changed title “ how to protect my electronics from a lightning strike?”

[RaymondR]

Oh ye of little faith.

We all know that whilst the overt reason for changing from 0183 to 2000 was the inadequate data rate and single direction of data flow, the overt reason was the manufacturers desire to have us scrap perfectly adequate instrumentation and replace it with their "new improved versions" (the more senior of us will recall the "planned obsolescense" scandal when it was discovered that manufacturers built in the limited lifetime of items)

In these modern times it's difficult to comprehend that young men once bought suits with the intention of being buried in them after a lifetime of usage.

[team karst]

Yep, nothing wrong with vacuum tube B&W tv. The warmup gave u time to think what u wanted to watch. [emoji41].

[SailingHarmonie]

Originally Posted by team karst

Yep, nothing wrong with vacuum tube B&W tv. The warmup gave u time to think what u wanted to watch. [emoji41].

You didn't have to think too hard, there were only three choices....

[AKA-None]

Originally Posted by SailingHarmonie

You didn't have to think too hard, there were only three choices....

Unless you had uhf :-)

[SailingPNW]

Originally Posted by RaymondR

Oh ye of little faith.

We all know that whilst the overt reason for changing from 0183 to 2000 was the inadequate data rate and single direction of data flow, the overt reason was the manufacturers desire to have us scrap perfectly adequate instrumentation and replace it with their "new improved versions" (the more senior of us will recall the "planned obsolescense" scandal when it was discovered that manufacturers built in the limited lifetime of items)

In these modern times it's difficult to comprehend that young men once bought suits with the intention of being buried in them after a lifetime of usage.

There is a huge difference between a suit and electronics. NMEA 0183 was an awful networking implementation. Thankfully it was replaced.

[RaymondR]

It was a perfectly adequate low cost system for the needs of those who do not require every instrument in the catalogue and them all interconnected. The entire data wiring system on my old boat cost about the same as one n2k T piece.

[team karst]

I believe 0183 had high CMRR, since it specs opto isolators. Isnt N2k rs422 under the covers with much less surge survivability. CMRR something like 7 volts and when u get over 20, i think think it breaks altogether.