First published 11 Jan 2022, updated and revised.
Tested LGB 55029 decoder with Firmware version number 220.127.116.11 with the following equipment.
From Marklin mDecoderTool3, 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 Test.mdtp file.
Adding extra WAV files to a new folder, for example
“My Documents\Maerklin\Soundbibliothek\Sounds\My sound\".
The file format should be 22050Hz, 16 bit, mono.
A 44100Hz WAV file will be downsampled automatically, so it will actually take about half the space in the decoder. In the 8MB available on the decoder you can store about 3.1 minutes of sounds in total.
The file patterns are:
Start.wav - played once when the slot is activated.
It's not interrupted by disabling the function.
01Loop.wav - played in loop until the function is disabled.
An iteration is not interrupted.
More NNLoop.wav files can exist in a sound folder.
Restart the app to show the new folder, add a new sound slot to the project and drag-n-drop the new folder on the slot.
Then map it to one of the functions.
The software doesn't make it easy to import your own sounds but in the end it works fine.