TrainCarts/API/SignAction/9 [en]

// When a [cart] sign is placed, activate when powered by redstone when each cart

       // goes over the sign, or when redstone is activated.
       if (info.isCartSign()
               && info.isAction(SignActionType.MEMBER_ENTER, SignActionType.REDSTONE_ON)
               && info.isPowered() && info.hasMember()
       ) {
           sendGreetingForCart(info, info.getMember());
           return;
       }
   }