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It is my understanding that Lenz were instrumental in creating the NMRA DCC standard and are a source reference for any ammendments.

Hornby have in conversation claimed that they have benchtested Hornby Digital against Lenz products as Lenz "are the standard" (Hornby's words). It seems like a waste of time for any digital manufacturer to be testing against all products on the market when Lenz are not going to deviate from a standard that they are instrumental in creating and maintaining.

If products do not work with Lenz consoles and accessories then they cannot claim to be compatible with the NMRA standard.

Am I right or wrong?


Happy modelling
Gary
 

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Gary you are right. the only system which appears to be different is hornby why don't hornby ask nmra to check out their decoder to see if it is nmra compatable
 

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QUOTE If products do not work with Lenz consoles and accessories then they cannot claim to be compatible with the NMRA standard. As Lenz are the only company to my knowledge who have fully conformed to the NRMA standard you would appear to be right.

QUOTE the only system which appears to be different is hornby Another thread seems to be saying that the Gaugemaster system has problems too.

I'm dying to hear whats coming next?
 

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Discussion Starter · #5 ·
Doug has used the Hornby decoders with his Lenz set up and they work fine within the limits of their specification.

And Lenz decoders will function with the Hornby Select console within the limits of its specification.

Proof that Lenz products work with Hornby Digital.

Logically, we can state that a product that does not function with Hornby Digital either is not NMRA compatible or has a hardware failure or both.

And we can state that if a Lenz product that does not have a hardware failure will not function with a Hornby Select console then the console has a hardware failure only.

Am I right or wrong?


Happy modelling
Gary
 

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You are pulling logic to the edges of it's boundaries...


I think to say if something is NMRA compatible / compliant / or conformant etc, the product has to go to the NMRA for testing. And it has to pass the tests.

Why can the Hornby decoder be 'read' by the Select, but not with the Lenz Cab controller? Surely there is a fault there somewhere?

Why are there issues with other DCC systems?
 

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It was when re-reading your review Doug that it got me thinking. It is fortuous that you have a Lenz set up as you can test anything for compatibility as it is THE most compatible system!


The Hornby Select has the ability to write only and not read. It will not tell you what the address of a loco is if you place it on the track.

A quote from your Hornby decoder review Doug:-

QUOTE I set up a test station on my desk (in from the cold garage) and connected up my Lenz Set 100 with the LZV100 command station and the LH100 hand controller.

Lenz command stations were used in the test. I believe it is not deemed a compatibility failure if a Lenz command station cannot read a Hornby decoder.

It is a property of the Hornby decoder that it cannot be read.

Again is this right or wrong?

Happy modelling
Gary

PS I do share Doug's concern that there seems to be issues with the products of many manufacturers. However if something works with Lenz then it has to be compatible with the standard. It would be illogical to say otherwise. I am catching up on a few episodes of Star Trek and Mr Spock has not yet encountered DCC...

...what would Mr Spock make of it?
 

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Dear All,

Getting an NMRA Conformance Warrant is a lengthy process, see here for all the details :-

NMRA Conformance and Inspection

For a list of current products that have the Conformance Warrants, see this page :-

NMRA Conformance Warrants

This list includes DCC and non-DCC products (there are more NMRA standards than just DCC). I have heard that NMRA did start off with Lenz as a basis, but that was a long time ago and I am fairly sure that both NMRA and Lenz have moved on from there. You will see Lenz, ESU, Bachmann and Soundtraxx equipment (amongst others) in the list of warrants, but no Hornby as yet.

If a piece of Lenz equipment on this list of products with a DCC conformance warrant does not work with a piece of Hornby equipment, then either one of them is faulty (Lenz or Hornby), or it is possible that Hornby are not following an applicable NMRA standard, or there is another issue (see my example later). You have to go through this NMRA testing procedure for DCC conformance to be sure.

For example, Lenz have an advanced from of feedback known as RailCom. I believe it has been submitted as a future NMRA Recommeded Practice, but is still under discussion. It is only supported by some manufacturers (e.g. Zimo and some others). If you are using RailCom in your Lenz controller and a Hornby decoder does not recognize the signals, this is outside the scope of the current NMRA standards and Hornby cannot be faulted for this. A Lenz customer can claim the Hornby decoder does not work (with RailCom), but Hornby could actually be fully conformant with the NMRA standards in this case and would pass the test as defined above. We just don't know the full story yet.

It's a very tricky subject, once you dig into the details, and we can only be certain about Hornby (or anyone else), if they do make the effort to obtain the conformance warrant. This makes discussions of incompatibility issues between say Prodigy and Hornby non-productive. Since neither have been through the NMRA testing procedured and obtained a warrant, how can anyone say (with any certainty) which one is at fault?
 

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QUOTE (Gary @ 17 Jan 2007, 12:09) <{POST_SNAPBACK}>It was when re-reading your review Doug that it got me thinking. It is fortuous that you have a Lenz set up as you can test anything for compatibility as it is THE most compatible system!


The Hornby Select has the ability to write only and not read. It will not tell you what the address of a loco is if you place it on the track.

A quote from your Hornby decoder review Doug:-
Lenz command stations were used in the test. I believe it is not deemed a compatibility failure if a Lenz command station cannot read a Hornby decoder.

It is a property of the Hornby decoder that it cannot be read.

Again is this right or wrong?
Not being able to read CV7 and CV8 is one of the issues that mean the Hornby decoder will *never* get a conformance warrant in it's current state since they are mandatory CVs within the Recommended Practice for CVs. To gain conformance a product must implement the Standards all mandatory sections of relevant RPs. A manufacturer can't pick and choose only the bits they want to implement and still claim conformance.

So, whilst there may be no "compatibility failure" in using a feature that simply doesn't exist, there is a failure to implement that feature (readback of CVs).

Andrew Crosland
 

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QUOTE (SPROGman @ 17 Jan 2007, 12:38) <{POST_SNAPBACK}>Not being able to read CV7 and CV8 is one of the issues that mean the Hornby decoder will *never* get a conformance warrant in it's current state since they are mandatory CVs within the Recommended Practice for CVs. To gain conformance a product must implement the Standards all mandatory sections of relevant RPs. A manufacturer can't pick and choose only the bits they want to implement and still claim conformance.

So, whilst there may be no "compatibility failure" in using a feature that simply doesn't exist, there is a failure to implement that feature (readback of CVs).
All this does make me wonder who (if anybody) Hornby consulted when planning their DCC system and deciding what features to include (or omit!). If they paid a consultancy fee for such information, I would suggest they ask for their money back
 

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There are a very large number of ommisons from the conformance list. Conformance is not mandatory.

If a product functions with another product that has a conformance warrant then it can claim to be compatible.

Issues seem to arrise when two products that do not have a conformance warrant are used together.

Logically if you have a console that has a conformance warrant then all compatible products should function with that console for those products to claim compatibility with the standard.

And logically you are simply unable to claim that a product is incompatible if it does not function with another product that claims to be compatible but does not conform.

Put simply...

...Hornby Digital will function with all products that have a conformance warrant and Hornby claim compatibility as a result.

...Hornby Digital may function with many products that claim compatibility but do not have a conformance warrant. Hornby Digital is not incompatible with the conformance standard in the event of not functioning with another non conforming product.

For example if Hornby Digital does not function with Digitrax then the Digitrax console user could not claim that Hornby Digital was incompatible with the conformance standard.

Am I right or wrong?

Happy modelling
Gary
 

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QUOTE For example if Hornby Digital does not function with Digitrax then the Digitrax console user could not claim that Hornby Digital was incompatible with the conformance standard.

Gary I admire your persistence in the face of adversity and overwhelming evidence. You have manfully defended the Hornby brand against all the odds. Good man. The facts remain however that your product has teething problems. Rank and file users will quickly loose interest in the product because of this. The principle problems with decoder compatibility wont go away unless Hornby change the parameters or specifications. You have to regard this as established fact and accept it. Hornby are not the be all of DCC, far from it, to date they
appear to have tackled DCC and the product launch in quite a rushed amateur manner. The perception is much more should have been done to support the product on launch. None of your legal arguments are going to change the hard evidence about the existing product. I repeat my statement of about 10 days ago wait for the Elite and lets see if Hornby are going to get their act together on DCC.
 

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QUOTE For example, Lenz have an advanced from of feedback known as RailCom. I believe it has been submitted as a future NMRA Recommeded Practice, but is still under discussion. It is only supported by some manufacturers (e.g. Zimo and some others). If you are using RailCom in your Lenz controller and a Hornby decoder does not recognize the signals, this is outside the scope of the current NMRA standards and Hornby cannot be faulted for this. A Lenz customer can claim the Hornby decoder does not work (with RailCom), but Hornby could actually be fully conformant with the NMRA standards in this case and would pass the test as defined above. We just don't know the full story yet.

Since Hornby have been touting RailCom as a feature of the Elite, one would hope that Hornby decoders would not be affected by its use. It's a shame that Hornby's standard (and currently only) decoder is "dumb" and won't talk to anybody.

As regards the main thrust of Gary's argument, equipment from two manufacturers without a conformance certificate may work with Lenz but it does not follow that that equipment will work with each other. It is possible that since the certificated Lenz equipment covers the full spectrum of the standards' variations that it can cover the potentially smaller range of the non-certificated equipment. These two smaller ranges may not overlap sufficiently for inter-operability to take place. Ergo, the only cast iron way to cover all bases is to buy certificated equipment. There is an argument for saying that buying anything less is doing the hobby a dis-service.

David
 

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these arguments are all well and good but the fact remains that there do appear to be problems using non hornby dcc components with the hornby system and visa versa the same with the guagemaster sytem.

For the consumer this is something which needs to be addressed because if people start purchasing products (as mentioned on other threads and other forums) only to find that there is a compatibility problem people are going to get upset and shout about it and eventually there may have to be some sort of trading standards investigation which could be very damaging or some manufacturers will get a bad reputation which may not be deserved simply because their products wont work with a lower priced system
 

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QUOTE Logically, we can state that a product that does not function with Hornby Digital either is not NMRA compatible or has a hardware failure or both.

If a product functions with another product that has a conformance warrant then it can claim to be compatible

Logically if you have a console that has a conformance warrant then all compatible products should function with that console for those products to claim compatibility with the standard.

No all it means is that it functions with the other product

Nice try Gary but this is not how it works. Hornby really must give you an award for your persistence in promoting their product despite all the facts to the contrary. Regardless of your flawed logic we do admire your tenacity.

An analogy of what you are saying is that because a Spanish speaker and an Frenchman can understand Latin it follows that a Spaniard can speak French.

QUOTE the only cast iron way to cover all bases is to buy certificated equipment. There is an argument for saying that buying anything less is doing the hobby a dis-service. I echo this statement. If you want to get into DCC buy a proprer established system like those of Lenz, ESU, Roco, Digitrax. If you go for an uncertified option you are going to generate more problems than it's worth.
 

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QUOTE If you want to get into DCC buy a proprer established system like those of Lenz, ESU, Roco, Digitrax. If you go for an uncertified option you are going to generate more problems than it's worth.

Some of those names do not have a conformance warrant.

QUOTE An analogy of what you are saying is that because a Spanish speaker and an Frenchman can understand Latin it follows that a Spaniard can speak French.

That analogy is incorrect. The correct analogy is that the Spaniard and Frenchman are able to communicate with each other in Latin. They cannot speak each others own respective language. Depending on each others understanding of Latin they communicate with each other well or badly.

I believe my logic to be correct. All compatible products can communicate with conformance products. Some compatible products may be able to communicate with some other compatible products. All conformance products can comunicate with conformance products.

I do agree that for the consumer who is planning to mix systems it should be made clear by every respective manufacturer who does not have a conformance warrant but who claims compatibility precisely what this means and how they have tested for compatibility. It is not incumbant upon manufacturers to test compatibility with every other product on the market. If a product works with Lenz then this should be sufficient to claim compatibility and manufacturers should state this if it is the case.

Stockists who sell DCC product and who do not ask how that product is being used only have themselves to blame in the event of a return due to a failure of the compatible product to communicate with another manufacturers compatible component.

Happy modelling
Gary
 

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I did believe that you intended your analogy to mean just that. The manner that I tweaked it was a bit off so I apologise for that.

I am very much clearer now as to the distinction between conformance and compatibility and hopefully others who were similarly confused are too.

This clarity may help with issues going forward. Anybody who has a compatibility issue should at the very least check the product having the issue with a console that has a conformance warrant.

Model Rail Forum has the use of a Lenz system so any Model Rail Forum DCC product review will beyond a shadow of a doubt establish credentials in this area!

So if manufacturers would like to send their gear to Model Rail Forum I am absolutely positive the product will get a thorough going over!


And if you don't then you only have yourselves to blame when things go wrong!


Happy modelling
Gary
 

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QUOTE (Gary @ 17 Jan 2007, 23:46) <{POST_SNAPBACK}>I do agree that for the consumer who is planning to mix systems it should be made clear by every respective manufacturer who does not have a conformance warrant but who claims compatibility precisely what this means and how they have tested for compatibility. It is not incumbant upon manufacturers to test compatibility with every other product on the market. If a product works with Lenz then this should be sufficient to claim compatibility and manufacturers should state this if it is the case.
I suggested just such a scheme a few weeks ago. If manufacturers would publish which clauses of the NMRA Specs each item in their range is intended to comply with, we can all make a much better judgement of what combinations of kit are likely to work and what are not. It is not a simple matter of conformity versus compatibility - you must take into account which features are incorporated, especially those which are not mandatory or are 'camp' specific such as LocoNet and XpressNet, as well as specific methods of implementation such as programming modes. It is when manufacturers try to get away with omitting mandatory requirements (such as CV readback on a decoder) that most of the confusion sets in.
 
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