I have bought many 5231 Viessmann decoders and installed them on my layout. They work great.
Last month I bought 2 more via a store in Germany. (all the others were bought in the USA)
When they arrived, the operation manual (which was enclosed with the 5231) did NOT say anything about being able to program them with the Marklin Mobile Station1. All the ones I have DID say they can be programmed with the MS1. That is the way I program them (using F1-F4).
When I connected them like I always do (and according to the description which was enclosed) after the first push on the small gold colored switch the Marklin turnout flipped a few times as it should.
But when I wanted to program the 5231 to the F1 setting from the MS1 nothing happened.
I tried it many different ways. Nothing worked. I even tried the second one I bought from Germany and it did not work either. When I tried one of my own, it worked fine.
Looking at them carefully, it showed on the back of the board of the Germain bought ones, a number 94107-03
On the ones I have it showed a number 94107-04
Is there a difference? Can anyone tell me?