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NMEA 2000 Certification, in the Panbo crossfire

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Written by Ben Ellison on Jan 22, 2014 for Panbo, The Marine Electronics Hub

It's great that boaters on research missions are constantly (though quietly) digging through the Panbo archives (or using Google's neat site search with the same intent). But when one is inspired to write a detailed, articulate rebuttal to a stand I took years ago on a subject that's still relevant, it deserves special attention. Bo Collins is working hard to figure out a new electronics system for his 53-foot 1978 Hatteras LRC trawler and he takes exception to my notion that NMEA 2000 certification is not an absolute must when choosing devices that use the data standard. What follows is his argument with my retorts interspersed and plenty of room at the end for you to add your opinion...


Ben, today was one of those occasions when I awoke at 1:30 AM and felt compelled, for God knows what reason, to pick up my iPad. Bouncing around your site I found "NMEA 2000 certification, the elephants in the room" and after reading it and all the posts felt that I must pen something from the perspective of a recreational user. The NMEA Certified and compatible issue struck me a bit different than it seems to have struck you.

Having read enough blogs I know that any posting of my comments will surely bring about a reprimand about being dependent on electronics. Enough please! Anyone that leaves port without some sort of paper chart and compass probably deserves whatever eventuality they get should the sea gods frown on their day of good spirits. Yes, I can read a paper chart and use a compass to plot a course. I can apply emergency measures to get me home if needed. I plan, plan, then plan again; which my wife believes is only done for the sake of driving her batty. I want comfort and safety when on the water. Let me rephrase that, I want safety then comfort when on the water. But, who in their right mind wants to pilot a 53-foot, 75,000 pound, 8-knot trawler through treacherous waters with a compass and chart? I like keeping a chart open at the helm to verify, but do we really want to return to the days of paddling at 20-degrees to the prevailing winds to find the next island? So, like my planning, I am spending hundreds of hours researching any equipment I put on my boat. And, that is where this whole NMEA 2000 stuff takes me.

Bo, You won't catch me judging anyone's paper chart habits. I think that there are lots of ways to navigate safely, plus lots of ways to do it badly, and that NMEA 2000 is key to the excellent electronic tools we now have available to use well.

I read over the NMEA Certification Process Overview on the NMEA web site. I gained a better perspective after reading all the posts resulting from your article. There are some very sharp folks that come to your site. But, it appears there are test methods and a verification process as outlined in the NMEA Certification Criteria and Test Methods (Appendix C in the Overview). There is a NMEA 2000 Certification Test tool which, from what I can tell, gathers specific data from a device so the data may be validated by NMEA. I am guessing that a NMEA representative doesn't show up with a ball bat and begin beating the everloving you know what out of the device, as they attest to do at Underwriters Laboratory. NMEA publishes a set of criteria, provides a verifiable means of testing, and offers NMEA 2000 Certification should the device pass the tests.

As I understand it, the NMEA 2000 certification tool -- which is essentially a special software program (that cost a lot of money to develop) -- is only intended to test the behavior of a device on an N2K network. Does it identify itself properly? Does it send out data in the right way that won't interfere with higher priority data-like switch commands? That sort of thing. But the tool does not test the data content of a particular device, which is a near impossible task if you think it through. So you could conceivably buy a certified NMEA 2000 depth transducer that did not output a standard N2K Depth message (PGN) or output one that was always wrong. Certification does largely assure that a product will not mess up a network, but the other issues are left for the market place to sort out :-) 

It would probably be a good thing if NMEA made public more of Appendix C in the Standard so that consumer doing serious research like you could better understand what is and isn't tested.

With respect to companies (manufacturers) who put NMEA 2000 Compatible, it is my opinion that NMEA should give fair warning, then use the power of the court to go after any company that violates the registered entity of NMEA 2000. I don't mean to sound harsh, and it appears that NMEA may have missed the boat (could not resist) by not registering the entire" NMEA 2000 Certified" name, to place the registered mark after the word "Certified" and group the statement, instead of after the 2000. I can bet dollars to donuts there is not a single recreational boater in my marina (mostly larger boats) that has a clue there is a difference between NMEA 2000 Certification and NMEA 2000 Compatible. Hey guys - yes, you guys that manufacture and go through all the trouble and costs of certifying a product - do you give a hoot about what happens should a non-certified device start throwing out odd sentences at our MFD's here in the real world? Help us out here, please.

I don't know about the details of NMEA's intellectual property claims, Bo, but I do know that the organization has sometimes at least threatened action against companies claiming N2K compatibility. In fact, I took a lot of flak from some readers for defending NMEA in such a situation. Happy to add that the offending company not only "came to Jesus," but is now an active participant in NMEA standards making.

How would Furuno, Raymarine, Simrad or others look at this? Not sure! From what I am reading they all have certified, non-certified, and certified but only compatible equipment. These companies know what they have. They know some of their equipment needs to be backward compatible, and they know NMEA 2000 is a voluntary standard. If I were king, I mean if I was a big wig at NMEA, I would gather all of the NMEA 2000 Certification members and let them know the perilous road NMEA is on if they don't stop the misuse of the NMEA 2000 trademark. Remember, we recreational boaters quickly get an attitude about an entire product line when one device starts acting up.

The big manufacturers do not run NMEA and their relationship with it seems complicated, as I tried to explain once.  The issue of daisy chaining N2K instruments, which I've also covered, illustrates what I mean. Furuno, Simrad, B&G and Raymarine all sell instruments with two N2K ports, so that an installer can chain them together easily -- as illustrated below in a 2008 Panbo entry called NMEA 2000 Outlaw!  -- even though the hardware details in the NMEA 2000 Standard don't permit it. NMEA explains why in this PDF


I believe that all the daisy chain instruments are what you term "certified but only compatible equipment," meaning they pass the certification software test but can't be certified just because of the hardware issue. And I keep hoping that some compromise will be reached -- like a sticker on every instrument warning about the danger of daisy chaining, which is completely optional. But so far the situation remains the same with neither side budging, and the Certification concept suffering.

That's not to say that some very good NMEA 2000 compatible equipment is available from all of the manufacturers, I'm sure there is. However, my comments stem from a non-profit national certification association I sit on that aggressively goes after companies that misrepresent by misusing the certification logo or name. First a cease and desist letter and, if necessary, they will go to legal means. Personally, I like it. My twenty-person company invests thousands each year supporting this organization. We donate money, time and technical expertise in support so they may pay operating expenses and maintain a reliable certification standard. I would rather drive the bus, or at least have a seat on the bus, than to be standing on the sidelines as it whizzes by; that's entirely my choice and goes to my point. Not only does my company benefit by advertising the organization's logo (which goes directly to client and consumer relations), those seeking certification know the difference between Certification and Certification-like. There are some well-founded competitors who chose to go in a different direction. When one used the logo without permission they were slapped down pretty hard. The organization I belong to does, in fact, set the standard. So, why not allow the public to know there is a difference?

Again, I do think that NMEA polices the NMEA 2000 logo. I also think that most manufacturers large and small are honoring and supporting the standard more than ever. I just noticed, for instance, that a bunch of BEP CZone devices just made the 2014 Certified list on NMEA's front page (even though they've been available for at least two years and work fine in my experience).  

Ben, I don't know if there are products that "probably won't work on a NMEA 2000 network" as purported by Steve in his article. I don't disagree with your comments either. My entire point, and yes, there is one, is the National Marine Electronics Association needs to do a better job of protecting their name and logo. Do that and it seems most of this controversy would go away. By protecting their name they protect recreational boaters for whom the standard is maintained. I personally believe using the NMEA 2000 Compatible is sales trickery. Heck, unless I am really missing the point, it does not seem that difficult. NMEA created a specific standard that sets criteria for a manufacturer to follow and provides a testing and verification process. Either it meets the standard or it does not. Certification always attests to an established set of criteria. We don't want to learn about "compatible," "works with, " or "NMEA Lite," (I threw that one in...) after we purchase and install a device by reading the fine print too late or by being laughed at by a NMEA installer. The product that is compatible may work just fine, but by NMEA protecting their registered trademark and name it protects me and all other recreational boaters. And please, to every manufacturer's sales rep and technician that may read this or see me coming to your booth at the next boat show: don't make me pull my pants down around my ankles as you try to enlighten me. Believe me when I say I am all ears and want to learn more than you can imagine. So just be honest. Your products are, or they are not, NMEA 2000 Certified.

I stand by my original thesis. NMEA and NMEA 2000 are great for boaters, I think, but certification is not a black and white issue for the reasons I've mentioned. Marine electronics is a relatively tiny, but vastly complicated, industry and thus, almost nothing about it is subject to simple dictates. I know, for instance, that Larry Anderson -- who was NMEA Technical Director during N2K's early years and then a principal at Maretron until he retired -- now feels that the "plug and play" aspect of N2K was oversold. Lots of do-it-yourselfers have had good experiences with it, but often a pro installer should be involved sooner rather than later. 

Finally, here is one example of how this concept, or point of mine, worked for me. I am currently installing Maretron digital gauge displays for Hercules and Big Boy (sorry, that would be my Detroit 4/53's). After researching several alternatives to get analog engine data to digital I settled on Actisense. The EMU-1 that does this fancy work IS NOT, as I could find, a NMEA 2000 Certified product. However, my research found that Actisense has many products that are certified and they are listed as a NMEA member. This gives me comfort, and I am better prepared to make an informed decision. Not all recreational boaters are ignorant. We just need the facts, please.        Regards, Bo

Well, Bo, that also seems like a good example of my attitude toward certification. In fact, I hadn't even realized that the EMU-1 was not certified (yet) though I've trying to pay more attention to that and I'm a big fan of the device. At any rate, thank you very much for articulating your concerns. I'll bet that you'll end up with a wonderful electronics setup and that you'll understand it. Now, I hope that interested readers will add their thoughts.

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