LGB MFX Decoder CV Help?

R

R. Wolfe

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25 Jun 2017
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#1
I have recently purchased a LGB 20985 Loco with a new MFX decoder. The Loco uses a 5-volt smoke unit and the performance is not up to par. It is very weak compared to some of my older LGB models. I contacted Marklin and they sent me another smoke unit. I also had the same problem with my 20755 Loco with MFX. I replaced the unit in the 20985 the other day and it worked about the same. I then tested the voltage output under load and it is right at 5.17 volts. Some of my older LGB with 5-volt smokers do very well but I find the voltage output is closer to the 6 volt range. I would like to raise the voltage slightly but I can't figure out which CV controls the smoke voltage. I use a Massoth system and recently was able to adjust the sound volumes for all the different sounds with out any issues. It seems as long as the cv value range is 0-255, the massoth system will adjust those cv's just fine. I just can't understand the manual and have no idea which cv controls smoke unit voltage. Does anyone know or have a more detailed CV list then what the loco manual provides? Any help would be much appreciated.

Thanks, Richard.
 
idlemarvel

idlemarvel

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#2
I guess the smoke generator is connected to one of the AUX outputs. To find out which one without opening the loco if you know which function key is set to turn smoke on you can trace that back to find out which AUX output it is, then you can set the voltage for that AUX output. The mapping of function keys to AUX output is quite complicated using bit settings. For example CV257 bits 2-7 (starting 0) are AUX1-6 for F1. Further complicated by the fact you can have different settings depending on whether the loco is moving backwards or forwards. Anyway if you can tell me which F fey sets smoke on I can tell you which AUX and which CV sets the voltage for that AUX. Or you can work it out from the attached doc (German).

https://www.maerklin.de/fileadmin/m...ionen/Umruestdecoder_mLD-mSD_CV-Liste_DCC.pdf
 
R

R. Wolfe

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25 Jun 2017
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#3
Thanks for the Quick reply. Function Key 7 turns the smoke on and off. I would like to raise the output voltage to around 6 volts (give or take) but stay under 7 volts. I also would like to know what the Default setting is in case I screw up. Thanks, Richard.
 
idlemarvel

idlemarvel

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#4
Okay Richard, what is the value of CV 292 . That sets what function key 7 does and will tell us which AUX output it is turning on. You could look it up yourself if you refer to page 12 of the document in that link, but if you are not familiar with German or bitwise CV programming then just give us the value and we can interpret it.
 
idlemarvel

idlemarvel

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#5
Also can we just be sure it is an MFX decoder? The 20985 from LGB just came with a decoder interface, it would be unusual for someone to fit a Maerklin MFX decoder rather than say a Massoth. Just to check please can you also tell us the value of CV 8?
 
R

R. Wolfe

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#6
My fault, it is a 21985 with Factory MFX. Register 292-295 Function Mapping Function F7 forwards Range is 0-255. Default is 292=4. Does this mean I also have to set 392-395 Function Mapping Function F7 backwards? If so, Range is 0-255 Default is 392=4.
 
idlemarvel

idlemarvel

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#7
Okay, value of 4 in CV 292 means function key 7 is turning AUX 1 on and off.
If you want function key 7 to have the same meaning if the loco is going backwards, then yes CV 392 should have the same value, which it seems it does.
AUX 1 voltage is set in CV 119, range 0-255. I assume that means 255 is full track voltage and 0 is no volts.
What is the current value CV 119?
 
R

R. Wolfe

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#8
Sorry for the delay, I had to step out for a while. The manual does not say what CV 119 is set too and I don't think my Massoth system will read ethe current CV settings like it will with a LGB / Massoth Decoder. The Manual says Register 115-135 Assignment Mapping phys. outputs, lights in the rear, Aux 1-6, compare 112-114
 
idlemarvel

idlemarvel

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#9
If you cannot read CV of MFX decoder with your current setup then that presents another problem. You can configure the decoder to talk "pure DCC" rather than MFX but I need to look up what that is.
EDIT
The CV to change the protocol search order is CV 50.
This is another bitwise setting.
By default it is probably set to 10 which is DC on and mfx on.
If you set it to value 2 it will turn mfx off while leaving the option for DC on. DCC is always "on" BTW.
This CV can be set using programming on main or programming track.
Then you should be able to read and write CVs with your Massoth setup as normal.
 
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R

R. Wolfe

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#10
Okay, I did not change cv 50 yet. I was actually able to read cv 119. It's value is reading 255. I also read cv 50 and it shows value of 10 so it appears to be reading this decoder just fine. I did not change cv50 yet. I only want to do that if I run into any problems. I was under the impression from all the forums that said you had to have a CS2 or CS3 to read anything but apparently they were wrong. This is Great News!
 
idlemarvel

idlemarvel

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#11
Maerklin decoders are DCC compliant as well as providing some proprietary extensions in the form of MFX, but they are sensible enough to let you turn that off if it is a problem.
CV 119 reading 255 implies AUX 1 is full voltage.
Earlier you said that the default for CV 292 was 4, now you can read CVs can you check it actually is 4.
I have read somewhere that 21985 has a pulsed smoke generator. Seems unlikely in the space inside a 1K but I don't have that model. But if it has, rather than a standard LGB 5v generator, it might need full track voltage.
Strangely I can't find reference to 21985 on the official LGB web site to verify this.
 
R

R. Wolfe

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#12
No, the 21985 is the regular 5-volt smoke unit. It is the weathered Toy Fair edition. I am (don't ask how I know as I am not supposed to know per wife) getting the one with Pulsed Smoker for Christmas. It is Model # 21980. That should smoke somewhat better. I can try to scan the CV chart from the manual and post it. It looks like I will have to explore the CV settings since I can read it. Maybe voltage is not 119? I know the smoke unit plugs directly into the circuit board and not the Decoder.
 
R

R. Wolfe

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#13
I appreciate all your help. You have defiantly cleared up a lot of unanswered questions and myths. I feel I am pointed in the right direction now and will keep you updated. I don't know how to thank you enough. I personally love these new decoders. The trains really run so smooth and flawless. The response time of the functions is instant with no lag. Amazing! Thanks again, Richard.
 
muns

muns

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#14
Maybe the voltage reg is performed on the board not the decoder as performed on other decoder ready locos.
 
idlemarvel

idlemarvel

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#15
I appreciate all your help. You have defiantly cleared up a lot of unanswered questions and myths. I feel I am pointed in the right direction now and will keep you updated. I don't know how to thank you enough. I personally love these new decoders. The trains really run so smooth and flawless. The response time of the functions is instant with no lag. Amazing! Thanks again, Richard.
My pleasure. I hope you reach a satisfactory conclusion. I agree about the Maerklin decoders, they are good and have some nice features, the main issue is the lack of English documentation. Dave.
 
idlemarvel

idlemarvel

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#16
BTW I found some instructions for the 21980 which is the green equivalent model to your black one, and that has a pulsed smoke unit, so I imagine your 21985 has too. Do you hear a fan running when the smoke is turned on?
"Smoke Unit
This model is equipped with a smoke unit. Fill the smoke stack only halfway with
smoke fluid. If you put in too much fluid, the smoke unit cannot produce smoke.
The smoke generator may be filled with a maximum of 5 – 6 milliliters / 0.2 fluid
ounces of 2421 smoke fluid.
Note: The smoke unit can be operated “dry“ without smoke fluid. When the tank is
empty, the heating and the fan will turn off after about 2 minutes."
 
R

R. Wolfe

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#17
No, no fan, I actually swapped smoke units all ready. The new unit smokes slightly better but not much. You can only put about 20 drops of fluid in at a time or it won't smoke. The original unit would smoke about 30 seconds then quit, then smoke again, then quit till it almost used all the fluid then it would constantly smoke for the last minute till it ran out. The new smoke unit smokes constantly but weak until it is almost empty then it smokes good for about the last minute before it runs out. 5.17 volts is probably the cause. If i could get even 5.4 volts, it would probably show a good improvement. My 20755 does the exact same thing and it has a factory installed MFX. Probably the same issue. I think Seuth may have a 4 or 4.5 volt version available so that may be worth a shot.
 
LGB333

LGB333

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15 Feb 2015
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#18
Hi R. Wolf - A couple of suggestions for you regarding Marklin's mfx decoder technology. One, if you with other forum members' assistance can't figure out how to adjust the CVs for your needs, I suggest you send an email to Marklin's Technical Support folks...….hopefully they'll be cooperative like the Massoth folks are. I also have a Massoth system and install decoders on my locomotives and for customers. The second suggestion about their German language documentation, there are several free German to English translators on the Internet...….you just copy and paste the German and instant translation. I use these when I'm searching on eBay.de for LGB items.

A negative point about Marlkin's mfx decoders. One of my customers with a DC/Analog layout bought the LGB 28443 RhB Railway 50th Anniversary Electric Locomotive and found that the factory-issued product has the Analog sound turned off. I contacted LGB USA folks and was told that you need a Marklin Central Station to re-set it to "on". The Massoth dealer in Baltimore, whom I collaborate with on technical issues, confirmed that point, but then someone on another large scale forum told me that my Massoth system should be able to make the appropriate adjustment to the mfx decoder. I liked the LGB 28443 design so well, I then bought one, too, but I run it on DCC and works well...…..there's a short video on my Website of it operating. So, in light of all this confusion about the mfx decoders and analog mode, I complained to LGB USA that LGB/Marklin should revert back to the Lehmann's mainstay technology used reliably for several decades, Massoth. That's especially true for 80% of the USA large scale hobbyists who still use only DC/Analog locomotives and layouts. Of course, Ron Gibson, the recently retired LGB USA manager, told me that USA hobbyists are only about 15% of lGB/Marklin's marketshare, so it's unlikely they focus very much on us buyers...…..Europe is their biggie arena.

Tom
 
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R

R. Wolfe

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#19
Tom, thanks for your reply. I also like the older LGB decoders as well as Massoth products. I wish they would have stayed with that format too. I have been using the Massoth XLS-M1 Decoders in a few new upgrades that I have done and they seem to run very well. They seem to be a little more finicky to program or read the CV's but very satisfied once you get them dialed in. I like the new MFX, the way they run out of the box is super using DCC. Their analog performance as far as sound is not so good. I just wish they were more DCC friendly as far as being able to program using my Massoth equipment. I don't wan't to invest in a CS3 just to be able to program them so I too agree with your comments. I have been wanting to try making some adjustments but have always been hesitant due to the fear of messing them up. I don't want to have to ship them back to Marklin. I have about 5 MFX locos now and finally have become brave enough to pick one to be the test unit due to poor smoke performance as mentioned above in the forum.

Richard
 
PhilP

PhilP

G Scale, 7/8th's, Electronics
5 Jun 2013
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#20
You can program them with your Massoth equipment..
BUT,
It is not a Massoth decoder, so things are not where 'we' expect, and certain 'nice to have' features on the Massoth, do not work because of this.
Case in point being changing the address:
The 'change address' feature on the Massoth system, changes more than just the address 'value', this is why it fails to a MFX decoder.. As long as you are aware of this, and change the individual CV's, then no problem.

I think it is more a case of it being 'different', having a lot more features (though Massoth are catching up, a little), so things are not where we expect them to be.

We are all so familiar with the way we have 'always' done it, change is hard. :think: