loco decoder

[geoffb41]

have a bachman loco and trying to read CV1 with my elite keeps returning XXX

i know it'sset at  no. 51 and i can select this loco on the elite and control its movement but any attempt at a CV read just gives XXX

tried CV8 to 8 but no difference

programming setup is working as can read other locos ok.

understand different brands may use a different CV to reset but how can u tell what brand of decoder it is if u can't read any CV 

 

[96RAF]

Read CV7 and 8 to find out the make and model by ref to the NMRA decode listing and then manufacturers site if they list such info, else ask their support desk.

 

XXX or 255 usually means the decoder cannot be read and it may be a characteristic e.g. some Hornby R8215 decoders could not be read at all or could only be read in Reg Programming Mode. Try that on your Elite, although you need to Google Reg Mode to see what each of the 8 registers contains.

[ColinB]

I am assuming that the decoder still functions. The decoder doesn't have any "stay alive" connected to it, because that can cause that to happen. I have had issues with the Elite doing the same with certain decoders, DCC concepts and Gaugemaster but Bachmann did seem to work ok. The only thing I did notice and this is weird, is turn the unit off wait about an hour and then try again. This is only a theory, but I think the Elite has a bit of a timing issues with some decoders because when mine didn't work I tried it on my second controller (a Fleishmann) and it worked every time. I also noticed that the Elite takes two attempts to read data whereas the Fleishmann did it in one. So I don't know if the Elite takes two readings and compares them or not.

[96RAF]

Elite conforms and is certificated to NMRA requirements Colin so no it doesn’t have its own read or write agenda.

 

@geoff

What firmware version is your Elite. This shows briefly at startup. Several fearures have been added over to years including better handling of other male decoders including bachmann if indeed that is the decoder in your loco.

Current Elite version is v1.45.

[ColinB]

All I can say is the Fleishmann does it differently and quicker. The NMRA requirements will just say how to read it probably with a timing diagram, probably similar to many other communication specifications I have read and implimented over the years. How you decide to do that in your software is usually up to the implimentor. So if they decide to read it five times or once they probably will still meet the specification, but I will have another read it of it, just in case. It can also depend on the devices (integrated circuits) you use to do the implimentation. From what I have managed to read DCC does not have a dedicated IC to do the hardware layer so I assume most of it is done in software and again this is highly dependant on how it is coded.

Either way without the technical jargon, I have found with some devices Elite doesn't always work as I am sure do many of the other controllers on the market at the moment. I did contact DCC Concepts asking if they had had any similar issues, but they seemed to have decided not to answer my very poilte email (and yes it was).

[96RAF]

Why don’t you go and read the NMRA DCC rules and regs then you can discuss particular points in the spec in a new thread rather than just assume they do this or they don’t do that.

I am sure the OP has no interest in the nitty gritty of DCC code, only does it work for him using the kit he has.

[ColinB]

To be quite honest it doesn't really matter, I am just answering the question. The Elite doesn't always work with all decoders. It could be because there is "Stay Alive" present or just an incompatibility with certain decoders. It seems to be an issue with newer designed ones. So to the average user as long as they know which controllers work with which decoders that is all that matters. I just don't use the ones that don't work with my Elite. Sometimes it is just the Elite gets itself in a muddle, which is why I suggested turning it off and starting again.

 

Incidentally I didn't mention code, just how it was implimented.

I will add the one really good bit about the Elite is the ease with which it sets up the read of data, basically the menuing function, the Fleishmann can read CVs but it is not so easy.  The only issue with the Elite is the lack of an "Enter" key , using that push button with the rotary encoder means it quite often enters the wrong value. That is why I use the Elite for programming and my Fleishmann for running the main layout.

[Stephen-1211844]

So to the average user as long as they know which controllers work with which decoders that is all that matters. I just don't use the ones that don't work with my Elite.

 

 

Wouldn't it be nice if we had a database of what is known to work with what. And a definition of 'works'?

[ColinB]

Yes it would but this is the Hornby website so some people get upset if you find fault with their gear. Since I wrote my first post I have been programming more decoders. With my Elite I can easily read Hornby, Zimo and LaisDCC decoders, that includes the sound options. It seems to have issues with the gaugemaster direct plugin 8 pin ones also in varying degrees DCC Concepts ones. I have tried a few others including Bachmann and they seem ok. Add "stay alive"/ "keep alive" (whatever you call it) and then you have issues. I think it is all to do with the programming period not being long enough the charge the capacitor in the "stay alive". Also function decoders and decoders not fitted to a motor also have issues. There also seems to be an undocumented feature (software bug) where if the Elite is left on for a while in normal mode and then switched to programming it gets it wrong. Also I have noticed that sometimes when reading it takes two clicks of the relay to read values, sometimes three. If it takes one it isn't going to work. As 96RAF says the read and write cycle are fixed by the specification, but it depends on timing functions on the decoder and what the software in the Elite does with the data.

[96RAF]

Are you saying Colin that the Elite has a bug but only in Standard mode but it doesn't bug in Classic mode, or are you speculating.

My Elite can be on all day and I have never had problems with it failing to program when required.

If you can give me firm evidence I will report it in for investigation. Such evidence would be Elite firmware state, how long does it have to be on before it bugs out, decoders that it does and/or doesn't work with before/after the fail event point, etc. Is it any decoder or just some, etc. Tabulate the data for simplicity of analysis.

Elite is featured so that it will program a function decoder i.e. being used without a motor load. This was introduced at v1.4.

It is well known that any controller can struggle to program when a stay alive is fitted. Controllers that usually will work are those without a dedicated Prog output that effectively program on the main at full track potential, like the Select and some others.

[ColinB]

Well 96RAF a lot of questions to answer. That bug has occurred about 3 times to me in programming mode in the last two years. To be quite honest I didn't consider reporting it as when it happens I just switch off the Elite and it works again. I can normally tell as I normally count how many times the relay clicks, when it goes wrong it only clicks once. The software level is the latest. Bugs like that are a devil to find but it is useful to let other users to know in case it happens to them. It is probably some timer wrap. Next time it happens I will collect all the necessary data.

I have tried to program a Zimo function decoder and yes it programs it perfectly well but it will not let me read any of the values. In fact it does the same with any decoder with no motor attached. When I get round to it, I was going to try putting a resistor across the motor terminals to see if that allows me to read it. It was in no way a criticism of the Elite, I think most devices have difficulty reading decoder values with no motor load attached. Every software device has issues, generally nobody notices them. I just flag them just in case someone starts binning their Elite.

As for the stay alive, as I said it is because in programming mode it pulses the track with DCC you can see it on my tester. The pulse though is unfortunately not long enough to charge up that huge capacitor. On a system where it programs at full track potential the capacitor is fully charged up so it will work. Sometimes it does work on the Elite, it depends if the capacitor is charged from before.

[96RAF]

Just collect whatever data you can Colin then it can be pushed up the chain for investigation.

As you say faults are a pest if you cannot repeat the problem time and again.

Are you talking about these Zimo function decoders...

http://www.zimo.at/web2010/products/funktionsdecoder_EN.htm

[Brew Man]

Doesn't the decoder have to support and be enabled for RailCom in order to read CVs? I'm sure it says that in the Elite manual, without going and fetching it.

[Howbi]

@Brewman......Decoders do not have to be Railcom® enabled in order to adjust CVs. That is just an additional protocol developed by Lenz which Hornby may utilise in the future such as in Loco Detection.......HB

[Brew Man]

@Howbi

I'm not talking about adjusting, (writing) CVs, I'm talking about reading their values. It's just what I read in the Elite Manual.

[Howbi]

@Brewman.........you are correct, the manual refers to Railcom® being enabled in order to read CVs although not all decoders are Railcom® equipped. I have never given it a thought before and never had to turn the Railcom® com feature on or off on any decoder..........HB

Edit to correct previous incorrect comment.....

[96RAF]

I think you will find (without me looking in the manual) that read-back is only possible on the main when Railcom is enabled. Usually PoM read-back is not possible, only write.

That is how Sapphire fuel burn is passed back to the Elite to kill the loco when it runs out of coal/water/fuel. CV28 sets Railcom comms, CV29 bit 3 enables/disables Railcom, CV146 turns fuel simulator on -off.