Electronics -- System Architecture

[Dockhead]

As to MFD's, I've decided that I will definitely want two at the nav table, considering how many different uses these devices have (so many more than the old ones did). Radar & plotter would be the obvious two uses, to put on two different screens, but then there is plotter & pilot, plotter and wind instrument, video feed, all kinds of possibilities.

The first MFD will definitely be the Zeus T8, and the second one could be a second such one, but what about the Simrad NSS7? It has VGA resolution (same as my old $5000 RL80CRC+). It won't take up as much instrument panel real estate. And with the rebates, it costs about a grand only! This is phenomenal value for money.

I think the usefulness of a T8 + NSS7 should be greater than the single T12 I had originally planned, for about the same money ($2400 + $1000).

Has anyone noticed the autopilot controls on these new plotter? These are the dog's danglies! I could seriously contemplate doing without a separate pilot control at the helm -- the plotters have dedicated buttons for engaging and disengaging the pilot.

[colemj]

Originally Posted by goboatingnow

The big disadvantage is trying to find potential cable fault in a boat wide 2K network,

....

NMEA2K should be star and hub , like Ethernet is now, way more resilience.

Dave

I agree that the topology isn't the most efficient or user friendly, but how often do you expect cable faults? The Maretron cabling and connectors we used are waterproof and seem almost milspec in quality. They are certainly far, far more robust than any of the NMEA0183, transducer and instrument cabling and associated connectors that we pulled out to replace. Not to mention the cheap (manufacturer supplied) junction boxes, etc used in the old install. Even the connections to commercial 0183 multiplexers are cheaper and more fragile than any of the N2K stuff we put in. Heck, the connections and supplied wiring on the back of most current instruments are more fragile than the Maretron cabling and connectors.

While I can foresee problems with individual instruments, I don't see issues with our cabling in the future. And troubleshooting individual instruments is a snap - you just unplug them.

Mark

[goboatingnow]

why T8s The B&G software is useful for racing, but after that theres not much in it with the NSO/NSE/NSS. Note I notice the NSS is the one that supports iPad integration best. ( and Go free as well. maybe the new Zeus touch might be a better variant. Simrad seem to be focusing the future around touch.

Has anyone noticed the autopilot controls on these new plotter? These are the dog's danglies! I could seriously contemplate doing without a separate pilot control at the helm -- the plotters have dedicated buttons for engaging and disengaging the pilot.

yes absolutely brilliant, Simrad are out ahead at the moment

Dave

[goboatingnow]

Originally Posted by colemj

I agree that the topology isn't the most efficient or user friendly, but how often do you expect cable faults? The Maretron cabling and connectors we used are waterproof and seem almost milspec in quality. They are certainly far, far more robust than any of the NMEA0183, transducer and instrument cabling and associated connectors that we pulled out to replace. Not to mention the cheap (manufacturer supplied) junction boxes, etc used in the old install. Even the connections to commercial 0183 multiplexers are cheaper and more fragile than any of the N2K stuff we put in. Heck, the connections and supplied wiring on the back of most current instruments are more fragile than the Maretron cabling and connectors.

While I can foresee problems with individual instruments, I don't see issues with our cabling in the future. And troubleshooting individual instruments is a snap - you just unplug them.

Mark

It depends, if you are using premade up cables/connector sets then yes, if field installable , then "maybe". I dont like long "bus" architectures, inherently its a single point of failure. It doesnt matter when you look at typical 2K installations today , possibly everything is within a few feet, But as we proceed ... well.

even cars today , side step it, My car currently has 3 independent Can buses, and a MOST bus as well.

Dave

[colemj]

I agree with you 100% on the architecture part, I just don't think cabling will be the problem with long bus networks going forward. Even the field installable connectors - yes, mistakes can be made assembling them, but if they are working on install, they are good to go.

My "car" engine is 15hp and I can strip and reassemble it with my eyes close - the last auto I owned was made in 1990 and I can't even imagine the electrical and communication complexity of a modern auto nowadays.

Mark

[Saltyhog]

I don't have any informed opinions, but I just wanted to say that I've found this thread to be extremely informative. I'll be going through this same exercise in a couple of years on our boat, so I mostly interested in the thought process and architecture in the design of the system while maintaining robustness. I'm an Electrical Engineer and a systems and software architect IRL. I've worked in safety critical industries for most of my career, so I'm no stranger to the issues accompanying the level of complexity of the systems being discussed. Not to drift the thread too much, but the concepts of complexity and single point failure has been touched on. It seems to me that the number potential failure points that can bring the entire boat to its knees is climbing quickly. However the connectors/cables etc. are more robust, so perhaps the likely-hood of any given failure is less, but the severity is potentially much greater. I can tell you that if a system like what is being described were to be installed on an aircraft, the FMEA (Failure Mode Effects Analysis) exercise would require more engineering man hours dollars than what this entire system plus installation will cost! Also, the redundancy and automatic fail-over requirements are huge. Even then, the first few installations generally reveal unanticipated failure modes. Almost always, the simpler the system overall, the happier the customer. So, although I truly appreciate the capabilities and features available with N2K systems, from a total boat standpoint, is my life any simpler with them? A a cruiser venturing far, will a failed bridge or connector kill the entire backbone? I'd be interested to hear from others who have gone from a simple system to something like this as to what their general experience has been. I don't want to be a slave to the complexities of the shipboard systems, and I'm likely more capable at solving issues than most boat owners. I'm not advocating either way, just posing the question from the standpoint of someone who attempts to rein in complexity on a daily basis. I don't wish to be a slave to my system, nor do I want to be a ludite.

[Dockhead]

Originally Posted by Saltyhog

I don't have any informed opinions, but I just wanted to say that I've found this thread to be extremely informative. I'll be going through this same exercise in a couple of years on our boat, so I mostly interested in the thought process and architecture in the design of the system while maintaining robustness. I'm an Electrical Engineer and a systems and software architect IRL. I've worked in safety critical industries for most of my career, so I'm no stranger to the issues accompanying the level of complexity of the systems being discussed. Not to drift the thread too much, but the concepts of complexity and single point failure has been touched on. It seems to me that the number potential failure points that can bring the entire boat to its knees is climbing quickly. However the connectors/cables etc. are more robust, so perhaps the likely-hood of any given failure is less, but the severity is potentially much greater. I can tell you that if a system like what is being described were to be installed on an aircraft, the FMEA (Failure Mode Effects Analysis) exercise would require more engineering man hours dollars than what this entire system plus installation will cost! Also, the redundancy and automatic fail-over requirements are huge. Even then, the first few installations generally reveal unanticipated failure modes. Almost always, the simpler the system overall, the happier the customer. So, although I truly appreciate the capabilities and features available with N2K systems, from a total boat standpoint, is my life any simpler with them? A a cruiser venturing far, will a failed bridge or connector kill the entire backbone? I'd be interested to hear from others who have gone from a simple system to something like this as to what their general experience has been. I don't want to be a slave to the complexities of the shipboard systems, and I'm likely more capable at solving issues than most boat owners. I'm not advocating either way, just posing the question from the standpoint of someone who attempts to rein in complexity on a daily basis. I don't wish to be a slave to my system, nor do I want to be a ludite.

Well, it's an important issue! My boat will NOT be brought to its knees even by a total failure of the entire N2K network.

Backups:

1. Updated paper charts, recently swung steering compass, a hand bearing compass, an old-fashioned long-lat GPS kept in a Faraday cage, and a skipper who learned navigation and pilotage before any of this electronic nonsense. I would not freak out even with the the whole boat electrical system dead. My first boat, in fact, didn't have a single item of electrical or electronic gear of any type. I don't sail anywhere without paper charts of the area, which, as much as I adore this new electronic technology, are still supreme for passage planning.

2. The old wind instruments and depth gauge on a separate Seatalk network, with the old displays.

3. An IPad with INavX and charts for all of Europe, and built-in GPS.

I think the N2K network will be very robust and I will be surprised if I have any problems (the old less robust Seatalk network peformed flawlessly for 12 years). But if it does flake out, it will not, by any means, be the end of the world. In business, it's called a "disaster recovery plan". We have that.

[Dockhead]

Originally Posted by goboatingnow

why T8s The B&G software is useful for racing, but after that theres not much in it with the NSO/NSE/NSS. Note I notice the NSS is the one that supports iPad integration best. ( and Go free as well. maybe the new Zeus touch might be a better variant. Simrad seem to be focusing the future around touch.



yes absolutely brilliant, Simrad are out ahead at the moment

Dave

Well, the B&G Zeus has a couple of useful features, not found in their Simrad cousins. For me, the coolest thing is graphing of wind speed and direction over time, so important when sailing. Then, you have laylines displayed on the plotter, and calculated according to your present AWA or whatever angle you input. Now that would not be rocket science, except that the laylines are corrected for tidal current drift. Now how cool is that? And currents are calculated with reference to differences between speed through water and SOG, COG and heading. That will be really useful.

And the difference in price between the Zeus and the comparable Simrad is quite modest, except only the 6.4" version, which is, in the case of Simrad, exceptionally cheap!!!

[Saltyhog]

Originally Posted by Dockhead

Well, it's an important issue! My boat will NOT be brought to its knees even by a total failure of the entire N2K network.

Backups:

1. Updated paper charts, recently swung steering compass, a hand bearing compass, an old-fashioned long-lat GPS kept in a Faraday cage, and a skipper who learned navigation and pilotage before any of this electronic nonsense. I would not freak out even with the the whole boat electrical system dead. My first boat, in fact, didn't have a single item of electrical or electronic gear of any type. I don't sail anywhere without paper charts of the area, which, as much as I adore this new electronic technology, are still supreme for passage planning.

2. The old wind instruments and depth gauge on a separate Seatalk network, with the old displays.

3. An IPad with INavX and charts for all of Europe, and built-in GPS.

I think the N2K network will be very robust and I will be surprised if I have any problems (the old less robust Seatalk network peformed flawlessly for 12 years). But if it does flake out, it will not, by any means, be the end of the world. In business, it's called a "disaster recovery plan". We have that.

Sounds like you've got things covered. If it seemed like I was trying to poke holes in what you have planned, I sure wasn't. It sounds great! I guess I was just saying that in general, the more complex a system is, the more "opportunities" there are for us having to fix it. How often does a shipboard system comprised of many different components from different vendors, completely satisfy all the needs and desires with little or no muss/fuss. I don't know and I'm really hoping that your system does (satisfy) because then I can use your planning and design as a starting point (or perhaps even copy it in total). I like the approach, I was just posing the question.

[lateral]

Originally Posted by arisatx

Dockhead:

I'm late to this discussion but -

1) Did you decide on a Rudder Feedback Unit? For the AC42, you can direct wire the traditional RF300 or an RF25 onto the N2K backbone.

2) Maretron now has a smaller version of the DSM250, the DSM150:



3) What's your energy budget? Have you modeled your system in N2K Builder?

4) How are you planning to handle termination at the masthead?

Does it have the same functions as the 250? As in configuring the SSC200?

[Dockhead]

Originally Posted by lateral

Does it have the same functions as the 250? As in configuring the SSC200?

As far as I can tell, it does. It even has the same screen res! (VGA). And it's half the price. Doesn't seem to make sense - $450 for a couple of square inches more screen. . .

[lateral]

It would want to as using a laptop is a PITA. Seems little point if it doesn't, apart from saving space. Odd they don't list that in the speil. Guess i'll have to download the manual.

[lateral]

FYI- Yes it does both basic and advanced config. (PNG's and 0183 )section 6.22 of the manual.
I guess the RD33 will not do that as it will require proprietory software. I prefer the RD33.(For my requirements)

[DeepFrz]

DH, I noticed that you are leaving out cooling water information. That could be a very valuable piece of information allowing you to shut down your engine before you do irreparable damage. Especially as you have mentioned using your engine in light winds. By the time you notice the temp gauge or the temp alarm comes on it could be to late.

[Dockhead]

Originally Posted by DeepFrz

DH, I noticed that you are leaving out cooling water information. That could be a very valuable piece of information allowing you to shut down your engine before you do irreparable damage. Especially as you have mentioned using your engine in light winds. By the time you notice the temp gauge or the temp alarm comes on it could be to late.

You are keen observer. Yes, I will install a cooling water flow alarm, but freestanding. I don't see any particular need to have this on the network. Same for gas and bilge alarms.