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I’m from the Old Skool way of doing things, very much the paper and pencil type. The collection of notes diagrams etc., has started to get o...

LGB 55029 Decoder Programming Marklin:

Tested LGB 55029 decoder with Firmware version number 3.2.2.2 with the following equipment.

Marklin 60971 Programmer and LGB 55129 Decoder Interface, using Marklin mDecoderTool3 version number 3.4.2.

Note for Marklin mDecoderTool3, used default L55029_mSD3_SpurG.mdtp as supplied, also created Test.mdtp files for checking and verifying correct operation. 


Marklin 60971 Programmer & LGB 55129 Decoder Interface with additional extension USB cable.


mDT3 (Märklin Decoder Tool) Version: 3.4.2, dated 13th October 2020.


mDT3 (Märklin Decoder Tool) Version: 3.4.2, Decoder Other Settings for Protocol selection, the option to TURN OFF  mfx is not available, will require the use of a conventional DCC system to access CV 50 to disable mfx.


For learning purposes created a .mdtp file.


The Instruction Manual whilst small in size, is sufficient to follow to design a Sound Project file, created one for Ivor the Engine, using external sound files that are not part of program or downloadable from the Marklin web site.

Uploaded to the LGB 55029 decoder, and operated from a Navigator.


Next step was to interrogate the generated .mdtp file, more out of curiosity, to see how it is constructed and what it contains.

The mTD3 program itself is obviously aimed at the mfx environment and Users, it's main uses are the ability to download project files produced by Marklin,  design and construct alternative Sound Projects, altering and reassigning Function Outputs, etc., then uploading to a decoder.

It does make fairly good job of dealing with what are common DCC CV's, does have a few quirks, but as it is not the primary source for configuring DCC CV's, not that troublesome.

What can be gleaned from the .mdtp file, that is of use to a DCC User, rather disappointingly not a great deal.

The file that contains the DCC information, Marklin decided to use the ..name= convention rather than the more familiar numbers to describe CV's, does make deciphering the contents a tad more difficult.


Was able to edit one of the files that contains the SUSI CV information, as yet have been unsuccessful in being  able to program these direct from a Navigator, a task for another day perhaps.


One item that has proved extremely useful and helpful are Loco Info Cards which are easily produced from the data provide by the Massoth Service Tool program.
Able to edit one of the files, provided the basics, decoder information, Function Outputs, Sound Files, as it's a HTML file, can be opened by LibreOffice, converted to a word processing file, can be edited, modified, images inserted, then converted to a .PDF file, result as below as in a Loco Info Card.