According to the catalog...

Marklin my world has plastic rails and IR control. Each starter set comes with one controller per locomotive, and each stand-alone locomotive is also supplied with a controller.

I guess each locomotive is "slaved" to a controller, so adding extra trains should be as easy as putting them on the tracks.

Regards,

Not so

Each locomotive and wireless remote have a "A" and "B" setting. Any, every train set to a letter will run the trains set to the same letter but not with separate control. So two set to the same letter run and stop together.  There are only 2 settings. Is there anyway to control more than two trains at a time. Thanks

Each set with two frequencies

As far as I know each Maerklin my world starter set comes with a controller that works on two different frequencies, A/B, C/D, or G/H. There was once a fourth set, E/F but there were interferences with C/D.

You have to check each starter set for the included frequencies.
Regards, Volker (Germany)

More confusion

I now have 3 sets all A-B   Two manuals show AB, one manual shows CD, but  the 3 trains and controllers are all AB.  I couldn't open the boxes before I ordered them.  Thanks very much for your replies. Norm