We already discussed that in another thread. The RD cannot "show the SD2 sounds". Do you expect the Ketron sounds to appear on the Roland display? No instrument is able to do that. The Roland RD is not designed as a controller keyboard, so when Roland describes how to connect a sound module they assume you can change the sounds on that module directly. This is not possible on the SD2, so you can only try to do it by changing sounds on the Roland which happen to have the same bank/program change midi messages as some sounds on the Ketron, or use e.g. an ipad app to change the Ketron sounds.