Disable MFX CV DisableMFXCV

[dunnyrail]

Hi at a pals today helping clean track. He has an old Massoth system and at every reset of system an newer MFX Maerklin loco starts up running unexpectedly. He has another MFX loco or two but only this one does it and regularly. He was told by matey at Scarborough that a CV can disable MFX but my pal forgot the relevant CV.

Apparently MFX can be disabled by a CV, anyone know which number on a current loco or just this one please?

The problem loco in this instance is a GE4/4 II LGB box Ref. 28446 but underneath sticker shows 20015070.

I wont begin to wonder why the Ref. No. is different on the sticker under the loco to that on the box!

 

[Nodrog1826]

There is a an option in CV 50 to select which protocol it responds to, it's bit 3 mfx off/on 0/8 default value is 10, but it's been some time (2019) since I switched off MFX on my new Crok, I will have to look and try and dig out what I did.

Edit after digging the instructions.

Check page 7 here 28446 instruction manual.

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static.maerklin.de

Now there is something in those setting that had me thinking, so as of 3 p.m. today I have read CV50 and it's value is set to 2, which is what I can sort of recall was the advice I was given at the time, appears to work, because when I set it to 0 it wouldn't only work anologue and not DCC, but we are going back 6 years.

 

[dutchelm]

The sticker is only a date reference. The first digits are a build date of 2020.

 

[PhilP]

Yes, CV 50 but NOT on a Massoth decoder!

This was one of the first 'gotchas' when Marklin brought out their MFX decoders..

PhilP.

 

[dunnyrail]

There is a an option in CV 50 to select which protocol it responds to, it's bit 3 mfx off/on 0/8 default value is 10, but it's been some time (2019) since I switched off MFX on my new Crok, I will have to look and try and dig out what I did.

Edit after digging the instructions.

Check page 7 here 28446 instruction manual.

Loading…

static.maerklin.de

Now there is something in those setting that had me thinking, so as of 3 p.m. today I have read CV50 and it's value is set to 2, which is what I can sort of recall was the advice I was given at the time, appears to work, because when I set it to 0 it wouldn't only work anologue and not DCC, but we are going back 6 years.

Thanks all for replies.

Yes bit numbers a ‘bit’ confusing. I am used to lots of options where you add the options for an outcome, this appears very different or perhaps Maerklin do not trust us with the other bits.

 

[Dan]

For DCC and DC operations you must change CV50 to 2. DC operation is always on as if you shut it off you would never be able to program the decoder again.

 

[dunnyrail]

For DCC and DC operations you must change CV50 to 2. DC operation is always on as if you shut it off you would never be able to program the decoder again.

Not sure that is what I understand, clearly many options of CV50 not stated in the MFX list, we had a go at it today and CV50 read 3, not a listed option. So we changed it to the default of 15, heck knows what that means? Not run away on a reset after a few tests but the running away never predictable as sometimes it does sometimes it don't. Time will tell.