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Discussion Starter · #1 ·
Hi all,

This post was originally made to the RMweb forums (no particular reason why I chose to post there first!) and following the very positive discussions and feedback from that I have spoken to a moderator on here and obtained approval for continuing the discussions over here. Apologies for its length!

I've updated the post from the one in RMweb simply to keep it current and correct following the discussions that have already taken place. If you want to follow that discussion as well then the link is here:;sk=t&sd=a

I guess this is probably going to kick off a flamewar but I feel it has got to be covered for the reasons covered below. If Moderators feel i'm being just too "picky" about this then feel free to bin the post. It is NOT intended to be pro-Hornby, anti-anyone else or any other sway, the topic is NMRA Conformance and having spent quite a bit of time conversing with the right people within the NMRA in the states, the people that look after the standard, manage the conformance warrants and do the testing, I feel i've built up a firm understanding of it now and i'm shocked and amazed at how little this is reflected in the manufacturers and forum members.

I will also add one last caveat by saying that just because a system does not have a Conformance Warrant does NOT mean it's rubbish, it does NOT mean it's any less compatible than any other system and i'm not intending this to imply that - it just means you don't *KNOW* it is, it's not *CERTIFIED* to be, and my basis for this post is that as a consumer I feel we should all be in a position to *KNOW* this as a fact so that we do not have a repeat of the disaster with the first gen Hornby decoders and their Select system.

I have noticed that "NMRA Compatible" and "Fully NMRA Conformant" are phrases often bandied around by forum members and manufacturers alike and I can't help but think that your average Joe is going to get very confused by this and end up buying something that they thought was tested and certified but actually was not.

There are a number of problems with NMRA Conformance of DCC at the moment. The first is that not enough manufacturers actually seem to understand the confidence and value this offers to a customer that their purchase is going to be compatible going forwards, there are simply very few manufacturers actually participating in NMRA Conformance testing, though it is on the up, very very slowly.

The second problem is that there is a lack of understanding about how long a warrant is valid for or for what equipment - well, the simple fact is that it is valid, indefinitely, for the life of THAT VERSION of the equipment. Change the equipment and the new version does not have a conformance warrant. I posed two specific examples to the NMRA which I will briefly summarise now:

The Hornby Elite
At Firmware versions 1.0 and 1.1 it did not have a conformance warrant. However, for version 1.2 it was tested and certified and if you look on the C&I page at the NMRA you can verify for yourself that Hornby Elite Firmware 1.2 has warrant number 2007-1011. However, Hornby then updated the firmware again and issued version 1.3 and I asked the NMRA if this would still be certified - it is NOT. A change requires a re-certification. This is not my opinion, this is fact from the NMRA.

NCE PowerCab
The NCE PowerCab is based very heavily on the NCE PowerHouse Pro, essentially miniaturising the command station and putting it in to the same cab that you use with the PowerHousePro. The PowerHouse Pro has Conformance Warrant 2005-011. So, is the NCE PowerCab therefore certified? It is NOT. It is a different unit and the NMRA view is that it requires testing of its own to obtain its own warrant. This is not my opinion, this is fact from the NMRA.

In another communication with the NMRA they let me know that they have recently introduced a new self-certification process whereby manufacturers can actually now test their equipment themselves - they have always made the specs and hardware diagrams available anyway, now the manufacturers can actually run the tests in house, produce the documentation and the NMRA simply then review it and either request further testing or issue the warrant right away if it all looks good. What surprises me about this is that when i've spoken to Dave Nichols at ZTC at various exhibitions, he has told me that they built their own NMRA test kit from the specs and they test to the standards - they just didn't send the kit off for the NMRA to do the testing and therefore it didn't have the warrant. But with this new process, surely all the ZTC kit can now quite quickly gain full certification? One wonders why the effort has not been made, but this points back to my initial comment that the manufacturers do not seem to feel the value in NMRA conformance and therefore only cursory glance is made.

Look through the warrant list, look at the names missing - there is no ecos, no digitrax, no mrc/gaugemaster etc for example. Major brands with well respected gear, but none of it with a conformance warrant. Credit goes to NCE for having a warrant on their Power House Pro unit of course.

I strongly urge everyone looking at equipment to find the kit that best suits them and then verify it has a warrant, if it does not have a warrant then tell the manufacturer that you will only buy certified kit and you really want theirs to be certified. If enough people do this then I feel we can turn things around and "NMRA Conformant" can actually mean something and provide us end-users with the level of confidence that we actually want when we're spending money on DCC systems.

Very little of the above post is my opinion, it has all come out through discussion with the NMRA specifically with the people involved with the DCC certification process.

I'm happy to answer any questions, pass them on or you could even just write to them yourself - I didn't get any special handshake, I just wrote to their normal contact addresses to confirm that the state of certification was as dire as it seemed looking through the issued warrant list, and discussions have followed on over the last year or so since then.

Here is a link to the Conformance and Inspection Warrants Issued list, if it is not on this list it does NOT have a warrant:

It is also worth re-iterating the difference between being technically conformant and being certified conformant with a warrant. There are probably many pieces of kit out there that are technically conformant but are not certified as such and we should all be chasing up our preferred manufacturers and asking them WHY they aren't seeking certification from the NMRA. If there's a good reason why not then rather than just avoiding it they need to be working with the NMRA to resolve these issues - such as the former FCC requirement (see below).

Now, if you have an NCE PowerCab, contact NCE and find out what they're doing about getting a warrant for the kit and if there's a reason why not then let's work to resolve it. It looks like a fantastic bit of kit and is let down by not having that magic warrant number.

It's up to us as consumers to make sure that vendors know that certification equals money because right now I think that consumers are not pressing the issue enough - if getting certification will not sell them any more units (or continuing to not have it won't cost them sales) then there is no business case for the money and time required to get the certification.

FCC Certification Requirement

After speaking with Dave Nichols at ZTC at a show he told me about the bizarre and unreasonable requirement to have an FCC certification in order to even apply for DCC certification. Just to expand on this for those that aren't aware, all electronic goods must have the CE certification for sale in Europe or FCC certification for sale in the US, it doesn't matter where it was made just where it's being sold. So obviously a manufacturer in europe who is not selling to the US doesn't need (or want) to go through the expense and time of an FCC certification just to get their DCC warrant.

I raised this with the NMRA and they pledged to investigate and review it, next time I brought it up it was confirmed as removed when the guy emailed me back almost straight away:

QUOTE The NMRA Board of Directors agreed with my recommendation to remove this requirement from our compliance program. Therefore, an FCC report is not necessary to be issued an NMRA Warrant. This does not mean the product is exempt from having an FCC certification. It only means NMRA is not concerned about it.

Please be advised that the FCC does recognize the CE certificate from Europe.


As consumers I want to understand why we are not more demanding of our favourite manufacturers to get their equipment certified. The NMRA want to improve adoption but are struggling to see how to move it forwards - my answer is to get consumers fired up about it and have them demand it from their manufacturers.

I would be very interested to hear from people who simply don't care about the conformance warrant, why that is and their understandings of it - perhaps there is a genuine failing in the standard, perhaps there is a failing in understanding - I am not here to preach that it's perfect, but to say that standards are a GOOD thing and if we aren't adopting it because it's flawed or wrong, we should be FIXING it. If there's nothing really wrong with it then we should all be demanding compliance from our preferred manufacturers and asking them why they aren't - perhaps they have good reasons, let's find them out and try to improve things.

So why am I getting my knickers all twisted about this anyway? Because we go out to lots of model railway exhibitions all over the country talking as an independent about DCC. Since we're not a vendor or a manufacturer we can give completely impartial advice - and our advice is ALWAYS to check the Warrant list and ONLY to buy kit with the conformance warrant because it provides that level of confidence about the compatibility of the kit. The problem is, there's next to nothing on the list at the moment! We do talk about non-warranted kit but only really in terms of encouraging them to try it out and then talk to the manufacturer about getting it certified if they like it.

I hope the discussion will proceed positively and constructively with a view to improving the standardisation situation for DCC, thanks for your time reading and contributing.


· Registered
52 Posts
Discussion Starter · #6 ·
QUOTE I'm amazed that Bachmann have said that ESU are able to self certify and that explains why there is no warrant listed under Bachmann for the Dynamis, but then they go on to say that they are working now to get one...

I think perhaps there is some confusion about self certification...

Self Certification is a process that lets the manufacturer do all the testing themselves, they produce the reports and so forth - and then it must all be submitted to the NMRA who will then issue the conformance warrant once they've reviewed the documentation and are satisfied that it is complete, so the NMRA are still the ones issuing the conformance warrants and this means that your equipment is still not able to display the logo until it's received one from the NMRA.

Richard - apologies for picking your post apart, I just want to reply in-context to save me waffling more than necessary

QUOTE every firmware change or revision does not invalidate a conformance warrant unless it changes these factors negatively.

Hmm, this is at odds with the reply I got from the NMRA, I posed the following question:

QUOTE Lastly, I wonder if you could clarify the continuation of warrants across versions. Presumably equipment at a particular version is tested but I don't have a way to know whether the equipment has been significantly changed since a warrant was issued - e.g. the NCE warrant was back in 2005, presumably three years later there's been some hardware modifications so do these require re-testing and how do I know this has taken place? I note that the Hornby Elite is listed at "version 1.2" - what happens now that they have released 1.3 firmware, is this version not covered by the warrant or is it assumed that once euqipment has received a warrant then all future versions are covered?

and the reply was simply as follows:

QUOTE Changing a version number requires retesting.

QUOTE Conformant: has been submitted for NMRA testing and passed the tests. a system cannot be called conformant unless its been tested by thenmra themselves.

Compliant: has been self tested and is warranted to comply. a product cannot use the term compliant and the dcc logo unless it meets the standards. if a Mfr does this then the NMRA will get on their case.

I guess this is part of my reason for wanting to understand things more simply - word-games like this are what confuse the general consumer, even more so when you throw in "compatible" with a further different meaning, the poor consumer now doesn't really know whether it's warranted or not.

Bottom line from what I have understood from NMRA is that it's very simple:

The NMRA issue conformance warrants. Conformance warrants can only be issued by the NMRA.
Manufacturers can complete the testing and submit the results, but cannot issue their own conformance warrant.
You can see if a piece of equipment has a conformance warrant by looking through the issued warrants list at the URL I gave earlier.

QUOTE For decoders there is only the very basic things such as CV29 and a couple of others such as DC/DCCcompatiblity and minor compulsory CV use... interestingly guess which decoder brand fails even this?

Well, there are also a slew of electrical tests to pass as well but yes decoders should be relatively easy to put through testing.

QUOTE They do it not because they couldn't be conformant (because universally they can...) but because they cannot afford to wait to bring a product to market and lose the timing edge that is critical to all marketing.

Then what I would ask the manufacturers is why they can't go ahead and bring it to market after their own testing is completed, and once it's out there then seek the NMRA warrant (which should just be submitting paperwork) which can be appended to their sales literature once it has been obtained - a couple of months delayed release definitely can hurt sales, but a couple of months after release adding the warrant number shouldn't cause any problems at all?

Thanks for the input Richard, I was hoping you'd chip in with your valuable experience!


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52 Posts
Discussion Starter · #7 ·
QUOTE I totally agree with the posititive intent of the concept but beware - some conformant product is markedly inferior to compliant product of other brands, so using the existence of the warrant as the sole arbiter of choice at this point in time is not necessarily doing the punters a positive service.

Well we certainly point that out and I have no problem at all in recommending that people wander around a show and talk to the manufacturers and vendors, try the equipment on the stands out and find what's good for them. There's so very little that actually DOES have a warrant that limiting to that is almost impractical unless it's a small layout suitable for an Elite or Dynamis really. But the recommendation is, if you find you like Digitrax (for example) then get in touch with them and tell them you want their kit conformant - more people start doing this and this will raise the "value" of the conformance warrant and we'll see more manufacturers considering it for their new kit; so chances are it isn't going to help them for the system they buy today but it might make it much more likely that their next system has a warrant.

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