The Märklin Mobile Station 2 (MS2) does not have a double header feature built into its user interface, but that is not the same as saying that it is not possible.
Double header on NMRA DCC compatible decoders is actually just an extra locomotive address as defined by CV 19. Any locomotive with a value set into CV 19 will participate in a consist with the value being the address of the consist.
Note: The following example uses PoM (Programming on Main) it is crucial that you use the PoM feature, so you wont overwrite any settings of the other locomotives on the track.
Locomotive A and B are to be in a double header.
- Make sure the locomotives run in the same direction.
- Find locomotive A on your MS2
- Enter programming mode using PoM (CV19 is a PoM value)
- Enter CV 19 and enter the value of the address (e.g. 10)
- Now find locomotive B on your MS2
- Enter programming mode using PoM
- Enter CV 19 and enter the same value as you did with the first locomotive
That's it. You're done. The locomotives are now in a double header.
If you want to break up the double header, you simply enter the value of 0 into CV 19.
The trains cannot be operated individually while in a double header.
PoM or Programming on Main is a feature where you can easily program a decoder directly on the layout, without having to fear that other decoders might pick up the settings. Not all CVs on the decoder are PoM compatible, so you will have to check with your decoder user's manual to see which CVs are compatible and which are not.