DSmain has an S88 interface. If you use Railuino System or DCC/MM2 Shield, you need to get S88 shield.
Desktop Station requires a S88 interface board to play with S88 function. If not use S88, not reuquired a S88 interface board. S88 interface board is not on sale. You have to make S88 interface board. Connector of S88 decoder uses 1.27mm pitch 6 pins header which you can get easily in worldwide. Wiring specification of S88 interface is as below. S88 shiled is now for sale in owner's site. Please contact us about S88 Shield.
Assignment S88 cable and Arduino
S88 Interface shiled
S88 Interface shiled with S88 decoder