NMEA Network

[colemj]

Originally Posted by goboatingnow

For example most people want some form of seperate instrument to display 2 or three main variables like wind, depth and speed and people also like dedicated autopilot controls. So the pure MFD route isnt really used that much and it brings up issues of redundancy

We need to define MFD here. They range from huge fully integrated chartplotter/radar systems to individual 4" square displays. Our new Simrad autopilot comes with a 4" MFD and not a separate instrument dedicated to the autopilot. It does control the autopilot, but it also displays wind, speed, depth, position, heading and navigation data. And some of that graphically. In fact, we are using it as a main display, along with the Furuno plotter until our 4" B&G displays arrive. Then we will configure them to display 2 or 3 main variables such as wind, depth, speed, position, etc data, and that will give us immense redundancy.

Mark

[goboatingnow]

as to MFD, ie Multi function displays, like the b&g trition, Ray I70 etc , sure but these are expensive beasties

[colemj]

Originally Posted by goboatingnow

Sorry Mark , I dont agree nor do companies like NASA marine agree. There is a plentiful market at the low end that want simple systems and commensurate prices, right now N2K is nowhere near the cheapest way to achieve some level of integration. There will always be a market for low cost simple systems. Garmin for example has several plotters that are not N2K compatible to save cost and complexity. There will always be a market for that.

If you are budget restricted then you have to install whats affordable, it would be silly to say leave out "depth" because you couldn't afford the N2K transducer.

As to future failed, that could be N2K your describing, a protocol dating from the 80s, badly specified and implemented in different ways by the manufacture, Will it be around in 10 years, I doubt it.

Dave

Dave

Yes, I agree about the low end. But that market has always been there and it hasn't changed in decades. Hummingbird depthsounders, etc. The OP did asked about as cheap as possible. Since he also asked about a complete refit, I think cheap as possible is short-sighted and almost always asking for trouble, but it does fit certain cases.

Future-failed is when the manufacturers are telling you they are abandoning that thing. No one is abandoning N2K. Yes, it has been around for over 20 years, but it was ignored for decades while everyone tried to corner the market with bastardized systems and this is the first year or so that the manufacturers have gone whole hog for it.

10 years is future-proof in technology. I hope switchable ethernet supplants it all next year, but I doubt it will. You will see N2K around as long as 0183 was, which is as much as you can hope for.

Might as well get in close to the ground floor.

Mark

[goboatingnow]

Yes, I agree about the low end. But that market has always been there and it hasn't changed in decades. Hummingbird depthsounders, etc. The OP did asked about as cheap as possible. Since he also asked about a complete refit, I think cheap as possible is short-sighted and almost always asking for trouble, but it does fit certain cases.

Nobody is arguing that, but to some its the difference between doing it or not. The other thing of course is that N2K doesn't really bring much to the party. Sure you could argue multi vendor sensors ( or is that which badge my Airmar sensor has on). Today you can do with 0183 what you can with N2K often at a lower cost, in fact with AIS, you still have to use it. ( can you believe that).

Then you have companies like Furuno driving a horse and carriage through the certification process, coupled with smaller manufacturers actually not certifying at all ( according to NMEA)

Yes it has its advantages, but there're not that great in reality

dave

[colemj]

Originally Posted by goboatingnow

as to MFD, ie Multi function displays, like the b&g trition, Ray I70 etc , sure but these are expensive beasties

Yes, they are. But they take the place of many other displays. Just one of them provides all the functionality of every other independent display on board. In the case of the Triton, it can even control the autopilot. In the case of the i70, it can display AIS from a black box receiver. Two of them take the place of a slew of independent displays while providing redundancy.

Given that, a refit will be less expensive using them than separate instruments.

For reference, the B&G Triton is almost the same cost as buying a remanufactured direct replacement for our damaged B&G Network display that only did one function. A single Triton does the functionality (and more) of all four of our Network instruments.

Mark

[colemj]

Originally Posted by goboatingnow

The other thing of course is that N2K doesn't really bring much to the party.

Uhhh, have you ever wired up a N2K network? And a 0183 network?

It is the difference between commandeering your neighbor's 6 yr old for an hour or so vs. paying a highly skilled technician for a couple of weeks.

And just try to mix and match a 0183 system.

I pulled 30lbs and hundreds of feet of wire out of our boat that was dedicated to 0183. Replaced it with a fraction of that for N2K.

Mark

[CarinaPDX]

Dave: I am not a "fanboy"! You should keep the pejorative comments off the forum. Fair enough to state your opinions; not OK to be labeling folks.

As someone who had to gut and replace pretty much the entire instrument package on my little boat, I had the advantage of a clean sheet of paper to start with. And with that in mind, I found the N2K solution to be best for me. I would agree that there are cheaper ways to go - which is to say less expensive and less capable. If one were to take an MFD plus N2K sensors from one of the big names (Furuno, Raymarine, Simrad for sure) and compares them to a standalone radar and sensors (each with their own displays) from the same companies, there won't be a lot of difference in price. Personally I don't want a wall of displays - I don't like the clutter. The MFD serves my needs perfectly. And N2K (as 0183) allows me to source equipment from multiple sources. The simplification to the ship's wiring has to be seen to be believed. Lots of good reasons to go that way.

As for redundancy, there are several solutions to getting that. I am using an Actisense N2k-USB bridge to my computer for the moment. One could also buy the multi-use displays from Maretron, Raymarine, and others as mentioned above. And there is now a wifi bridge for the iPad. Redundancy of the display is an advantage of N2K, not a disadvantage.

Saying that you doubt that N2K will be around in 10 years is moot, to say the least. N2K is based on the CANBUS technology, which is found in virtually all modern cars and trucks, and many marine engines. It has proven to be robust. Assembling systems from it is very easy (MUCH easier than integrating with 0183).

I am not necessarily down on using cheap instruments with little or no integration - that approach has its place. But having installed an N2K system with modules from at least 6 different vendors I can confirm that it works well and is something that is worth stretching a bit to buy. YMMV

Greg

[goboatingnow]

Originally Posted by colemj

Uhhh, have you ever wired up a N2K network? And a 0183 network?

It is the difference between commandeering your neighbor's 6 yr old for an hour or so vs. paying a highly skilled technician for a couple of weeks.

And just try to mix and match a 0183 system.

I pulled 30lbs and hundreds of feet of wire out of our boat that was dedicated to 0183. Replaced it with a fraction of that for N2K.

Mark

In a large vessel sure, but I'm talking about your average cruiser with say wind depth and speed an autopilot and a chartplotter, GPS, theres not that much more wiring, yes its not as neat in that you dont have devicenet etc ( mind you you could put nice connectors on 0183)

You have a range of multiplexors to get over the single talker etc.

Yes its not as neat, but it works

We of course can leave the discussion as to how a single bus, strewn about your boat, seriously compromises your system and makes it extremely difficult to fault find. The damm thing should have been star based IMHO.( or at least star/bus)

dave

[Kettlewell]

We of course can leave the discussion as to how a single bus, strewn about your boat, seriously compromises your system and makes it extremely difficult to fault find. The damm thing should have been star based IMHO.( or at least star/bus).

How are you supposed to find the problem when the cable accidently gets crimped someplace you can't see, or someone accidently puts a screw right through it? Doesn't that knock out the whole system?

[xymotic]

Originally Posted by colemj

Uhhh, have you ever wired up a N2K network? And a 0183 network?

It is the difference between commandeering your neighbor's 6 yr old for an hour or so vs. paying a highly skilled technician for a couple of weeks.

And just try to mix and match a 0183 system.

I pulled 30lbs and hundreds of feet of wire out of our boat that was dedicated to 0183. Replaced it with a fraction of that for N2K.

Mark

I agree. If you are linking one thing to another. there's little to no difference.

If you have 3, 4 or more devices, especially if you want to mix a different brand or two or three in, 0183 gets real complicated, real fast. Even stuff that should be dead simple like hooking a VHF to a GPS. one manufacturer will have 3 wires, the other 4, one manufacturer will call a wire nema "in" and the other will say Nema "A" and the third will call it "earth" The orange wire hooks to the purple wire on that instrument but to the yellow and white wires on the other.

[goboatingnow]

I am not a "fanboy"!

I didnt mean you persay, I mean its important not to loose sight of ones critical facilities.

As for redundancy, there are several solutions to getting that. I am using an Actisense N2k-USB bridge to my computer for the moment. One could also buy the multi-use displays from Maretron, Raymarine, and others as mentioned above. And there is now a wifi bridge for the iPad. Redundancy of the display is an advantage of N2K, not a disadvantage.

Yes but explain how the bus is made redundant. get a short somewhere in the many metres of bus cabling all over the boat, then try to find it , short of having a TDR unit.!! I designed CAN systems, I know where all the skeletons lie!.

Dave

[xymotic]

Originally Posted by Kettlewell

How are you supposed to find the problem when the cable accidently gets crimped someplace you can't see, or someone accidently puts a screw right through it? Doesn't that knock out the whole system?

How is 0183 any better? Is it the ducer, the wiring, the multiplexor, the MFD or the seatalk converter?

With 2k you can unplug and jump/bypass a section very easily and troubleshoot fault.

AND you can also just remove a fault and keep on trucking.

[colemj]

Originally Posted by goboatingnow

We of course can leave the discussion as to how a single bus, strewn about your boat, seriously compromises your system and makes it extremely difficult to fault find. The damm thing should have been star based IMHO.( or at least star/bus)

dave

Won't argue the topology, but the network backbone itself is a simple, inexpensive single cable. It is hardly strewn about the boat unless it was purposefully and carelessly done this way. And did I mention it was a single cable? An inexpensive one at that? Just run another if you worry about it.

You must be joking about fault finding? Unplugging devices one at a time will isolate a fault in seconds. So will disconnecting sections of cable. We have a large network system running through 2 hulls, a bridgedeck, up a mast and through an arch and I can pinpoint a fault area in under 30 seconds. And that is without using Maretron's free network analyzer software.

Have you ever had to fault find a 0183 system?

Mark

[bstreep]

Would it be possible...

For us to just address the OP's question? Rather than argue merits of systems?

[CarinaPDX]

OK Dave, you don't like N2K. It could have been designed better. Agreed. But we weren't on that committee. As consumers we have to choose from what the manufacturers make available. And for now N2K is head and shoulders above the alternatives.

The question of the certification situation is a mess, to be sure. That is an organizational issue, not a technical one. Products that are "compatible" and not "certified" still interoperate just fine. The costs involved in getting certified are very high, including: dues, documentation, software, approval fees. NMEA could have, and should have, made certification more affordable. But as a consumer, it matters very little.

The question of damage to wiring and fault-finding is not an issue in practice. It is very easy to narrow any problem down to a single link by just knowing which instruments are responding and which aren't. Having just pulled out the wires from all of my old instruments I can confirm that the quality of the Maretron DeviceNet cables is better than all of the old wiring. (To be fair, Simrad's Simnet cables are much lower quality.)

I spent a bit of time integrating as much as possible my older instruments using 0183. N2K is a huge leap ahead - the network effects are very useful. One solid state compass supports the autopilot, AIS, radar/chartplotter, wind instrument, etc. One GPS is available everywhere (but yes, there are multiple backups). The speed and heading data are used throughout (in addition to SOG and COG from the GPS). Pretty much everything works better, and is more informative, as a result. So how to value that?

Greg